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Polyvinyl alcohol
Polyvinyl alcohol
Polyvinyl alcohol
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Polyvinyl alcohol
Names
Other names
PVOH; Poly(Ethenol), Ethenol, homopolymer; PVA; Polyviol; Vinol; Alvyl; Alcotex; Covol; Gelvatol; Lemol; Mowiol; Mowiflex, Alcotex, Elvanol, Gelvatol, Lemol, Nelfilcon A, Polyviol und Rhodoviol
Identifiers
ChEMBL
ChemSpider
  • none
ECHA InfoCard 100.121.648 Edit this at Wikidata
E number E1203 (additional chemicals)
KEGG
RTECS number
  • TR8100000
UNII
Properties
(C2H4O)x
Density 1.19–1.31 g/cm3
Melting point 200 °C (392 °F; 473 K)
1.477 @ 632 nm[1]
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
1
0
Flash point 79.44 °C (174.99 °F; 352.59 K)
Lethal dose or concentration (LD, LC):
14,700 mg/kg (mouse)
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Polyvinyl alcohol (PVOH, PVA, or PVAl) is a water-soluble synthetic polymer. It has the idealized formula [CH2CH(OH)]n. It is used in papermaking, textile warp sizing, as a thickener and emulsion stabilizer in polyvinyl acetate (PVAc) adhesive formulations, in a variety of coatings, and 3D printing. It is colourless (white) and odorless. It is commonly supplied as beads or as solutions in water.[2][3] Without an externally added crosslinking agent, PVA solution can be gelled through repeated freezing-thawing, yielding highly strong, ultrapure, biocompatible hydrogels which have been used for a variety of applications such as vascular stents, cartilages, contact lenses, etc.[4]

Although polyvinyl alcohol is often referred to by the acronym PVA, more generally PVA refers to polyvinyl acetate, which is commonly used as a wood adhesive and sealer.

Uses

[edit]

PVA is used in a variety of medical applications because of its biocompatibility, low tendency for protein adhesion, and low toxicity. Specific uses include cartilage replacements, contact lenses, laundry detergent pods and eye drops.[5] Polyvinyl alcohol is used as an aid in suspension polymerizations. Its largest application in China is its use as a protective colloid to make PVAc dispersions. In Japan its major use is the production of Vinylon fiber.[6] This fiber is also manufactured in North Korea for self-sufficiency reasons, because no oil is required to produce it. Another application is photographic film.[7]

PVA-based polymers are used widely in additive manufacturing. For example, 3D printed oral dosage forms demonstrate great potential in the pharmaceutical industry. It is possible to create drug-loaded tablets with modified drug-release characteristics where PVA is used as a binder substance.[8]

Medically, PVA-based microparticles have received FDA 510(k) approval to be used as embolisation particles to be used for peripheral hypervascular tumors.[9] It may also used as the embolic agent in a Uterine Fibroid Embolectomy (UFE).[10] In biomedical engineering research, PVA has also been studied for cartilage, orthopaedic applications,[11] and potential materials for vascular graft.[12]

PVA is commonly used in household sponges that absorb more water than polyurethane sponges.[citation needed]

PVA may be used as an adhesive during preparation of stool samples for microscopic examination in pathology.[13]

Polyvinyl acetals

[edit]

Polyvinyl acetals are prepared by treating PVA with aldehydes. Butyraldehyde and formaldehyde afford polyvinyl butyral (PVB) and polyvinyl formal (PVF), respectively. Preparation of polyvinyl butyral is the largest use for polyvinyl alcohol in the US and Western Europe.

Preparation

[edit]

Unlike most vinyl polymers, PVA is not prepared by polymerization of the corresponding monomer, since the monomer, vinyl alcohol, is thermodynamically unstable with respect to its tautomerization to acetaldehyde. Instead, PVA is prepared by hydrolysis of polyvinyl acetate,[2] or sometimes other vinyl ester-derived polymers with formate or chloroacetate groups instead of acetate. The conversion of the polyvinyl esters is usually conducted by base-catalysed transesterification with ethanol:

[CH2CH(OAc)]n + C2H5OH → [CH2CH(OH)]n + C2H5OAc

The properties of the polymer are affected by the degree of transesterification.

Worldwide consumption of polyvinyl alcohol was over one million metric tons in 2006.[6]

Structure and properties

[edit]

PVA is an atactic material that exhibits crystallinity. In terms of microstructure, it is composed mainly of 1,3-diol linkages [−CH2−CH(OH)−CH2−CH(OH)−], but a few percent of 1,2-diols [−CH2−CH(OH)−CH(OH)−CH2−] occur, depending on the conditions for the polymerization of the vinyl ester precursor.[2]

Polyvinyl alcohol has excellent film-forming, emulsifying and adhesive properties. It is also resistant to oil, grease and solvents. It has high tensile strength and flexibility, as well as high oxygen and aroma barrier properties. However, these properties are dependent on humidity: water absorbed at higher humidity levels acts as a plasticiser, which reduces the polymer's tensile strength, but increases its elongation and tear strength.

Safety and environmental considerations

[edit]

Polyvinyl alcohol is widely used, thus its toxicity and biodegradation are of interest. Tests showed that fish (guppies) are not harmed, even at a poly(vinyl alcohol) concentration of 500 mg/L of water.[2]

The biodegradability of PVA is affected by the molecular weight of the sample.[2] Aqueous solutions of PVA degrade faster, which is why PVA grades that are highly water-soluble tend to have a faster biodegradation.[14] Not all PVA grades are readily biodegradable, but studies show that high water-soluble PVA grades such as the ones used in detergents can be readily biodegradable according to OECD screening test conditions.[15]

Orally administered PVA is relatively harmless.[16] The safety of polyvinyl alcohol is based on some of the following observations:[16]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Polyvinyl alcohol

View on Grokipedia
from Grokipedia
Polyvinyl alcohol (PVA), also known as polyethenol, is a synthetic, water-soluble with the idealized [\ceCH2CH(OH)]n[ \ce{CH2CH(OH)} ]_n or (\ceC2H4O)n(\ce{C2H4O})_n. It is characterized by a linear chain structure composed of repeating units, typically obtained through the partial or complete of , where acetate groups are replaced by hydroxyl groups in the presence of an alkaline catalyst like or . PVA is non-toxic, conditionally biodegradable, and biocompatible, with a molecular weight generally ranging from 20,000 to 200,000 g/mol, which affects its and film-forming capabilities. PVA exhibits high solubility, particularly for grades with 87–99% , dissolving to form clear, viscous solutions at elevated temperatures (above 80°C for fully hydrolyzed forms), while being insoluble in most organic solvents such as alcohols, hydrocarbons, and oils. Its physical properties include a temperature of approximately 85°C, good tensile strength, and flexibility, making it suitable for forming strong, transparent films. Chemically, PVA is stable under neutral conditions but can undergo cross-linking with agents like to enhance mechanical durability. Commercially produced since the via a continuous of in , PVA is manufactured in various grades differing in degree of and molecular weight to tailor its performance for specific uses. The production involves of followed by controlled , yielding a versatile material that is the largest volume water-soluble synthetic globally. PVA finds extensive applications across industries due to its adhesive, emulsifying, and barrier properties. In textiles and manufacturing, it serves as a warp sizing agent and coating to improve strength and printability. As an component in polyvinyl acetate emulsions, it is used in wood glues, , and . In biomedical fields, PVA-based hydrogels are employed for , wound dressings, and scaffolds owing to their and tunable swelling behavior. Additionally, it is utilized in films, pods, and as a stabilizer in pharmaceuticals and .

Overview

Definition and basic characteristics

Polyvinyl alcohol (PVA), also known as polyethenol, is a water-soluble synthetic produced by the of , with the idealized repeating unit -[CH₂CH(OH)]ₙ-. This process replaces acetate groups with hydroxyl groups, yielding a material that is odorless, tasteless, and appears as a white to cream-colored granular powder. PVA cannot be synthesized directly via of , as the monomer is unstable and spontaneously tautomerizes to under standard conditions. As a , PVA contains multiple hydroxyl (-OH) groups along its chain, which confer unique hydrophilic properties and enable hydrogen bonding, setting it apart from other vinyl polymers such as (-[CH₂CH₂]ₙ-), which is hydrophobic and insoluble in water due to the absence of polar functional groups. This polarity makes PVA highly versatile as a water-soluble binder and stabilizer in various formulations. Key characteristics of PVA include substantial tensile strength, flexibility, and excellent emulsifying capabilities, arising from its ability to form stable films and interact with both aqueous and non-aqueous phases. Commercial grades typically exhibit degrees of from 500 to 5000, corresponding to molecular weights of approximately 20,000 to 200,000, and degrees of ranging from 88% to 99%, which influence , , and crystallinity.

Historical development

Polyvinyl alcohol (PVA) was first synthesized in by German chemists Willy O. Herrmann and Wolfram Haehnel through the of using in , marking the initial preparation of this -soluble . This discovery laid the foundation for PVA's development, though early efforts focused on overcoming its high for practical applications. Herrmann and Haehnel filed initial patents for PVA production processes in the mid-1920s, with subsequent advancements in exploring its potential in adhesives and coatings, but commercialization remained limited due to technical challenges. In the , PVA saw its first significant commercial breakthrough in the United States, where introduced the product under the trade name Elvanol, targeting uses in textiles, sizing, and adhesives. This period aligned with growing demand for synthetic materials amid industrial expansion, enabling PVA's entry into global markets despite wartime disruptions. By the late , production scaled up, with Elvanol establishing PVA as a versatile in . Post-World War II, PVA production surged in the and , driven by rising needs in textiles and ; led this expansion, with commercializing PVA fibers () in 1950—the world's first synthetic PVA fiber—for applications in clothing and industrial fabrics. Global output grew rapidly, supported by resumed operations in and the U.S., as PVA's adhesive properties proved essential for wood bonding and amid postwar reconstruction. By the , production reflected widespread adoption in consumer and industrial sectors. The evolution of PVA grades progressed from early low-hydrolysis variants (around 80-90% hydrolyzed), which offered better for adhesives, to higher-hydrolysis types (over 98%) by the 1970s and 1980s, enabling specialized uses like high-strength films. Pharmaceutical applications of PVA have developed with enhanced purity standards to meet regulatory requirements for excipients in drug formulations. In the 2020s, sustainable production initiatives have gained prominence, with manufacturers like and OCI supporting sustainable manufacturing processes to reduce environmental impact. Concurrently, post-2010 shifts toward bio-based alternatives, such as starch-derived or biomass-composite polymers, have accelerated amid pressures in and films, addressing the origins of PVA. As of , global PVA production reached approximately 1.4 million metric tons annually. This timeline underscores PVA's transition from a synthetic to a cornerstone material, now evolving amid pressures.

Chemical Structure and Properties

Molecular composition

Polyvinyl alcohol (PVA) is a synthetic characterized by its repeating unit of -CH₂-CH(OH)-, resulting in the idealized (C₂H₄O)ₙ, where n represents the typically ranging from hundreds to thousands. This linear structure consists of a carbon backbone with pendant hydroxyl groups, which arise from the process and subsequent modifications. PVA is primarily produced through the partial or complete of (PVAc), which has the repeating unit -CH₂-CH(OCOCH₃)-. The reaction involves the cleavage of bonds, replacing groups with hydroxyl groups, as represented by the equation: [−\ceCH2CH(OCOCH3)−]n+n\ceH2O→[−\ceCH2CH(OH)−]n+n\ceCH3COOH[-\ce{CH2CH(OCOCH3)-}]_n + n \ce{H2O} \rightarrow [-\ce{CH2CH(OH)-}]_n + n \ce{CH3COOH} This process, often catalyzed by or in methanolic solution, allows control over the degree of , influencing the final composition. The standard structure of PVA features head-to-tail linkages, where the hydroxyl-bearing carbon of one monomer connects to the methylene carbon of the next, forming a predominantly atactic configuration with no regular stereoregularity along the chain. This atactic nature stems from the free-radical polymerization of vinyl acetate precursor, leading to random placement of hydroxyl groups relative to the chain axis. The degree of hydrolysis, typically 80-99% for commercial grades, determines the proportion of residual acetate groups, which can introduce slight comonomer-like variations and affect chain regularity. While PVA is generally linear, structural variations include possible branching from side reactions during of the precursor, and crosslinking can be induced post-synthesis through chemical agents targeting the hydroxyl groups. Syndiotactic forms, with higher regularity in hydroxyl placement, are achievable via advanced methods such as of vinyl trifluoroacetate followed by , yielding syndiotactic contents up to 69%. Tacticity and sequence distributions in PVA are confirmed through (NMR) , particularly ¹H and ¹³C NMR, which resolve triad (mm, mr, rr) and higher-order configurations based on differences in the methine and methylene protons or carbons. Recent studies in the 2020s have utilized advanced NMR and scattering techniques to elucidate PVA's , revealing self-organized dissipative structures in solution that influence chain folding and formation at the nanoscale.

Physical and chemical properties

Polyvinyl alcohol (PVA) exhibits a range of physical properties that make it suitable for various material applications. Its typically ranges from 1.19 to 1.31 g/cm³, depending on the degree of and processing conditions. PVA has a temperature of approximately 75–85 °C, above which it transitions from a glassy to a rubbery state, influencing its flexibility and processability. The material decomposes before fully melting, with decomposition onset around 200 °C and a reported of 180–230 °C for different grades, where fully hydrolyzed PVA shows higher thermal endurance than partially hydrolyzed variants. PVA demonstrates high solubility, particularly for lower molecular weight grades, dissolving up to 100 g/L at 20 °C, though decreases with increasing hydrolysis degree and molecular weight. Chemically, PVA's numerous hydroxyl groups enable strong intramolecular and intermolecular , which contributes to its excellent film-forming ability and properties. This network also imparts resistance to oils, greases, and most solvents, as the polar structure repels non-polar substances. However, PVA is susceptible to degradation in strong acids or bases, where or swelling can disrupt the chains, and it remains stable in weak acids, bases, and organic solvents under ambient conditions. Aqueous solutions of PVA exhibit pseudoplastic behavior, with viscosities ranging from 4 to 50 cP for 4% solutions at 20 °C, varying by molecular weight and concentration; higher molecular weights yield more viscous solutions suitable for coating applications. In terms of thermal stability, PVA undergoes at elevated temperatures above 200 °C, forming conjugated polyene structures through elimination of molecules, which can lead to discoloration and chain scission. This process enhances thermal degradation resistance up to approximately 380 °C for dehydrated forms but limits long-term exposure to high . Optically, PVA films are highly transparent, with refractive indices around 1.477 at 632 nm, due to the uniform amorphous and crystalline regions formed by hydrogen bonding. Properties of PVA vary significantly by grade, particularly with molecular weight and hydrolysis degree, affecting mechanical and rheological performance. Higher molecular weights increase crystallinity, leading to tensile strengths of 20–80 MPa and elongations at break of 200–400% in , with greater chain entanglement enhancing overall and modulus. For instance, low molecular weight PVA (around 20,000–50,000 g/mol) offers higher elongation but lower strength, while high molecular weight grades (above 100,000 g/mol) provide superior tensile properties. In emerging applications since the 2020s, PVA's rheological properties are critical, showing strong shear-thinning behavior where decreases with increasing (e.g., from 10^3 to 10 Pa·s under typical conditions), enabling precise filament deposition; temperature elevation to 180–200 °C further reduces melt for improved printability, though excessive heat risks degradation.
PropertyTypical ValueInfluencing FactorsSource
Density1.19–1.31 g/cm³ degree
Glass Transition Temperature75–85 °CMolecular weight
Decomposition Temperature> °CCrystallinity
Water Solubility (low MW)Up to 100 g/L at 20 °C degree
Solution Viscosity (4 wt%)4–50 cP at 20 °CMolecular weight
Tensile Strength20–80 MPaMolecular weight
Elongation at Break–%Molecular weight

Synthesis and Production

Laboratory preparation

Polyvinyl alcohol (PVA) is commonly synthesized in laboratory settings through the alkaline of (PVAc), a process that replaces groups with hydroxyl groups. This method typically involves dissolving PVAc in a methanol-water and adding a base catalyst such as (NaOH) or (KOH) at concentrations of 1-5 wt%, followed by heating at 40-60°C for 1-2 hours to achieve a degree of hydrolysis ranging from 88% to 99%, depending on reaction time and catalyst amount. An alternative approach is acid-catalyzed , which allows for more precise control over residual content, particularly for partially hydrolyzed PVA. In this procedure, PVAc is reacted with (HCl) in an acetic acid-water medium at mild temperatures (around 50-70°C) for several hours, producing copolymers with tunable hydrolysis degrees suitable for specific applications. The PVAc precursor required for hydrolysis is prepared via free radical polymerization of vinyl acetate monomer. This lab-scale reaction often employs emulsion polymerization in water with initiators like 2,2'-azobisisobutyronitrile (AIBN) or benzoyl peroxide at 60-80°C under nitrogen atmosphere, yielding PVAc latex with molecular weights typically in the range of 10,000-100,000 g/mol. Following hydrolysis, the PVA solution is purified by precipitation into excess acetone, which causes the polymer to solidify and separates it from unreacted materials and byproducts like sodium acetate. The precipitate is then filtered, washed multiple times with acetone or water to remove residuals, and dried under vacuum at 40-60°C to obtain a white, powdery product. In laboratory preparations, the degree of is monitored via , where a sample undergoes with excess base, followed by back-titration of unreacted with to quantify residual groups, ensuring reproducibility and desired properties. Typical overall yields for these bench-scale syntheses exceed 90%, reflecting efficient conversion under controlled conditions.

Industrial manufacturing processes

Polyvinyl alcohol (PVA) is produced on an industrial scale through a two-step process involving the of (VAM) to form (PVAc), followed by or alcoholysis to replace groups with hydroxyl groups. Global production of PVA reached approximately 1.4 million tons in 2023, driven by demand in adhesives, textiles, and sectors. accounts for over 60% of global capacity, with major producers including Sichuan Works and Anhui Wanwei Group. Leading producers also include Co., Ltd. in , which operates a U.S. plant with 40,000 tons annual capacity (completed in 2016); and Sekisui Chemical Co., Ltd., also in . The step typically employs suspension or solution methods in aqueous or organic media, using initiators such as peroxides at temperatures of 50–70°C to yield PVAc with controlled molecular weight. This is followed by continuous methanolysis, where PVAc dissolved in reacts with a base catalyst like to produce PVA and as a . The reaction proceeds under mild conditions, around 40–60°C and , with the degree of (typically 88–99%) dictating the final product's solubility and properties. Key process parameters emphasize efficiency and yield, including precise control of concentration (0.1–1 wt%) to achieve uniform alcoholysis and minimize gel formation. Byproducts such as (produced at about 1.68 times the weight of PVA) and residual acetic acid are recovered through and , enabling of methanol and acetic acid back into the VAM production cycle for economic viability. Energy consumption in the overall process is optimized through heat integration, though specific figures vary by facility; recent assessments highlight efforts to reduce it via advanced designs. Industrial operations favor continuous processes over batch methods for scalability, allowing steady-state operation and higher throughput in large reactors. Post-2020 advancements include explorations in solvent-reduced systems to lower environmental impact, though methanol-based continuous alcoholysis remains dominant for commercial production. Quality control relies on (GPC) to analyze molecular weight distribution, ensuring polydispersity indices of 1.5–3.0 for consistent performance in end-use applications. Supply chain challenges, such as the 2022 VAM shortages in due to production halts and logistical issues, led to PVA price spikes exceeding USD 1,800 per metric ton in during Q1, underscoring vulnerabilities in raw material availability. By 2025, shifts toward bio-derived VAM—produced via of or —are emerging, with companies like integrating sustainable feedstocks to enhance PVA's eco-profile while maintaining process compatibility.

Applications

Industrial and commercial uses

Polyvinyl alcohol (PVA) plays a pivotal role in the adhesives industry, where it serves as a primary binder in water-based formulations for wood glues, such as those akin to Elmer's, providing strong to porous substrates like wood and due to its film-forming and emulsifying properties. It is also employed in bonding applications, including remoistenable labels and seals, enhancing durability and flexibility. Approximately 25% of global PVA production is allocated to adhesives, underscoring its significant market presence in this sector. In textiles, PVA is predominantly used as a warp sizing agent, applied to yarns to increase tensile strength, abrasion resistance, and weavability during the weaving process, after which it is removed via to avoid contamination. This application leverages PVA's ability to form a protective, flexible on fibers, benefiting both natural and synthetic materials, and constitutes about 44% of overall PVA consumption. PVA contributes to the paper and industries through coatings that impart grease and resistance, improving barrier performance against oils, vapors, and moisture in and other materials. It also functions as a binder in nonwovens, enhancing structural and printability in products like tissues and absorbent papers. Beyond these core areas, PVA acts as a in latex paints to control and improve application properties. In ceramics, it serves as a temporary binder and during processing, facilitating powder compaction, green body formation, and reducing friction for better shaping and outcomes. For medical packaging, PVA enables the production of sterilizable films suitable for pharmaceutical and healthcare applications, owing to its , non-toxicity, and oxygen barrier characteristics. Emerging applications in the 2020s include PVA as water-soluble filaments for support structures, enabling the fabrication of complex geometries with easy post-processing dissolution in , a use that has expanded significantly since 2015. Additionally, PVA films are utilized as encapsulants in unit-dose laundry detergents, providing convenient, dissolvable packaging that reduces material waste. Adhesives and textiles collectively account for roughly 70% of PVA's end-use consumption, with market projections for 2025 highlighting growth in biomedical sectors driven by partially hydrolyzed grades for pharmaceutical and innovations.

Specialized derivatives like polyvinyl acetals

Polyvinyl acetals are formed through the acid-catalyzed of polyvinyl alcohol (PVA) with s, where the hydroxyl groups on PVA react to create linkages, often resulting in a crosslinked . This process typically involves immersing or dissolving PVA in a solution containing the aldehyde and an acid catalyst, such as , leading to the elimination of water. The general reaction can be represented as: [−\ceCH2CH(OH)−]n+\ceRCHO→[−\ceCH2CH(OCH(R)O)−]n/2+\ceH2O[-\ce{CH2CH(OH)-}]_n + \ce{RCHO} \rightarrow [-\ce{CH2CH(OCH(R)O)-}]_{n/2} + \ce{H2O} where R denotes the aldehyde substituent. Common aldehydes include formaldehyde for polyvinyl formal (PVF) and butyraldehyde for polyvinyl butyral (PVB), with the degree of acetalization controlled by reaction conditions to balance solubility and mechanical properties. Among the key types, PVB is widely used as an interlayer in laminated safety glass, particularly for automotive windshields, where it enhances impact resistance by holding shattered glass fragments in place. PVB interlayers dominate the laminated glass market, accounting for over 55% of the segment in 2023 due to their optical clarity and adhesion to glass surfaces. In contrast, PVF finds applications in wire enamel coatings and adhesives, providing electrical insulation and structural bonding in electrical components. These derivatives exhibit enhanced properties compared to unmodified PVA, including superior solvent resistance and improved to plastics and metals, which stem from the hydrophobic groups reducing water solubility. PVB, in particular, offers significantly greater toughness, enabling it to absorb high-impact energy without fracturing, a critical attribute for safety applications. Industrial production of polyvinyl acetals, especially PVB, involves dissolving PVA in a water-alcohol mixture, followed by the addition of the aldehyde and acid catalyst under controlled to achieve partial acetalization while retaining some hydroxyl groups for compatibility. Global PVB production exceeds 2 million metric tons annually, driven by demand in and automotive sectors. Beyond core uses, PVB is used in some encapsulations, where it protects photovoltaic cells from environmental degradation due to its UV stability. PVF is employed in coatings for its and thermal resistance. Recent advancements in the include research on bio-based acetals derived from sustainable aromatic aldehydes, offering biodegradable alternatives to petroleum-derived versions while maintaining mechanical integrity. Additionally, technologies for PVB laminates from end-of-life windshields have progressed, with EU-funded methods enabling efficient separation and reprocessing of PVB for closed-loop , potentially recovering over 125,000 tons annually and reducing .

Safety and Environmental Aspects

Health and safety considerations

Polyvinyl alcohol (PVA) exhibits low acute oral toxicity, with an LD50 greater than 15 g/kg in rats, indicating minimal risk from ingestion under normal conditions. It is classified by the International Agency for Research on Cancer (IARC) as Group 3, not classifiable as to its carcinogenicity to humans, based on insufficient evidence from animal and human studies. In powder form, PVA acts as a mild irritant to eyes and skin, potentially causing redness or discomfort upon direct contact, though it is not a significant sensitizer. Exposure to PVA dust through may lead to irritation, including coughing, throat discomfort, or nose irritation, particularly in poorly ventilated areas during processing. However, PVA is considered safe for contact applications, with the U.S. (FDA) granting it (GRAS) status for use as an indirect in coatings and films at specified levels. Safe handling of PVA requires the use of (PPE), such as gloves, , and respirators, especially when generating during or to minimize irritation risks. As a combustible solid, PVA can form mixtures with air when heated; its is approximately 79°C (open cup), and is around 440°C, necessitating proper ventilation and ignition source controls in industrial settings. PVA is registered under the European Union's REACH regulation (EC 1907/2006), with ongoing safety assessments confirming its low hazard profile for registered uses. The (OSHA) sets a (PEL) of 15 mg/m³ for total dust as an 8-hour time-weighted average to protect workers from respiratory effects. For medical applications, such as implants or systems, pharmaceutical-grade PVA is required, meeting stringent purity standards (e.g., low residual and ) to ensure . Recent studies from the 2020s have reinforced PVA's for implant applications, demonstrating minimal inflammatory response and good integration with tissues in composite coatings for orthopedic and dental implants.

Environmental impact and

Polyvinyl alcohol (PVA) exhibits slow biodegradability under aerobic soil conditions, with degradation rates influenced by molecular weight and environmental factors; studies indicate partial mineralization over weeks to months via microbial action, though exact half-lives vary and can extend to 50-100 days in low-oxygen soils. In marine environments, PVA degradation occurs primarily through microbial consortia, including species, which depolymerize the via extracellular enzymes, achieving up to 42% degradation in controlled assays over extended periods. This process involves a two-step mechanism: initial oxidation followed by , as demonstrated by lignolytic fungi and , highlighting PVA's potential for natural breakdown but underscoring the need for optimized conditions to accelerate it. The production lifecycle of PVA contributes approximately 2.4 kg of CO2 equivalents per kg of in a cradle-to-gate assessment, primarily from energy-intensive of and raw material sourcing. As a water-soluble used in textiles and detergents, PVA enters streams, where up to 77% may persist through treatment plants, raising concerns about microplastic-like that could mobilize contaminants in aquatic ecosystems. Life cycle analyses emphasize that while PVA's aids dispersion, incomplete degradation in effluents amplifies its environmental footprint compared to insoluble s. For waste management, PVA is suitable for incineration with energy recovery, converting the polymer to heat and reducing landfill volumes, though emissions control is essential to minimize air pollution. Chemical recycling via methanolysis or hydrolysis can recover vinyl alcohol monomers from PVA waste, enabling circular reuse, particularly for industrial scraps. These methods support energy-efficient disposal over landfilling, aligning with broader polymer waste strategies. Sustainability initiatives include pilot-scale production of bio-based PVA using renewable feedstocks like bio-ethylene derived from , with 2024 projects demonstrating reduced dependency in precursor synthesis. Green manufacturing processes have achieved lower water usage through optimized and effluent , cutting operational impacts by up to 30% in select facilities. In the , regulations under the and microplastics restrictions promote biodegradable polymers like PVA, exempting water-soluble variants from bans if they meet aerobic and anaerobic degradation thresholds; as of October 2025, enforcement of Regulation (EU) 2023/2055 requires suppliers to provide use and disposal instructions for exempted products.

References

  1. https://www.consumerreports.org/environment-sustainability/what-is-polyvinyl-alcohol-what-is-pva-used-for-a1054051485/
  2. https://www.bpf.co.uk/plastipedia/polymers/polyvinyl-alcohol-pvoh.aspx
  3. https://www.fao.org/fileadmin/templates/agns/pdf/jecfa/cta/61/PVA.pdf
  4. https://www.fda.gov/files/food/published/GRAS-Notice-GRN-927-Polyvinyl-alcohol.pdf
  5. https://ntrs.nasa.gov/api/citations/20205002815/downloads/King_Glen_PhD_Thesis_Norfolk_State_8-31-20_final.pdf
  6. https://pmc.ncbi.nlm.nih.gov/articles/PMC6332455/
  7. https://www.sigmaaldrich.com/US/en/product/aldrich/363170
  8. https://cameochemicals.noaa.gov/chemical/7523
  9. https://pubs.acs.org/doi/10.1021/prechem.3c00051
  10. https://bioresources.cnr.ncsu.edu/resources/preparation-and-characterization-of-polyvinyl-alcohol-based-composite-reinforced-with-nanocellulose-and-nanosilica/
  11. https://pmc.ncbi.nlm.nih.gov/articles/PMC10893462/
  12. https://digital.hagley.org/1972341_0578
  13. https://apps.dtic.mil/sti/tr/pdf/ADA288990.pdf
  14. https://www.kuraray.com/global-en/company/history/vinylon_poval/
  15. https://www.wacker.com/cms/en-us/products/insights/a-binder-connects-the-world.html
  16. https://www.tandfonline.com/doi/pdf/10.1163/156855508X292383
  17. https://www.merckmillipore.com/Web-INTL-Site/en_US/-/USD/ShowDocument-Pronet?id=202009.076
  18. https://www.pharmaexcipients.com/news/polyvinyl-alcohol-revival/
  19. https://fox5sandiego.com/business/press-releases/ein-presswire/854204546/global-polyvinyl-alcohol-market-to-reach-usd-2412-61-million-by-2034-driven-by-hydrolyzed-grades-diverse-uses
  20. https://www.nature.com/articles/s41578-021-00407-8
  21. https://www.mordorintelligence.com/industry-reports/polyvinyl-alcohol-pva-market
  22. https://www.publish.csiro.au/ma/fulltext/MA25027
  23. https://www.sciencedirect.com/topics/chemical-engineering/polyvinyl-alcohol
  24. https://pubs.acs.org/doi/10.1021/ma60029a010
  25. https://www.sciencedirect.com/science/article/pii/S0032386122001616
  26. https://www.sciencedirect.com/science/article/abs/pii/S002196731100255X
  27. https://www.sciencedirect.com/science/article/abs/pii/S0032386101004931
  28. https://www.scribd.com/document/494823169/Characterization-of-Polyvinyl-Alcohol
  29. https://pubs.acs.org/doi/10.1021/acs.macromol.3c02047
  30. https://www.kuraray-poval.com/fileadmin/technical_information/brochures/poval/kuraray_poval_basic_physical_properties_web.pdf
  31. https://www.chemicalbook.com/article/polyvinyl-alcohol-properties-production-process-and-uses.htm
  32. https://www.sciencedirect.com/topics/materials-science/poly-vinyl-alcohol
  33. https://4spepublications.onlinelibrary.wiley.com/doi/10.1002/pen.24855
  34. https://www.echemi.com/cms/2620441.html
  35. https://link.springer.com/article/10.1007/s10812-015-0048-5
  36. https://analyzing-testing.netzsch.com/en-US/polymers-netzsch-com/commodity-thermoplastics/pval-polyvinyl-alcohol
  37. https://pmc.ncbi.nlm.nih.gov/articles/PMC8588446/
  38. https://www.iieta.org/download/file/fid/102405
  39. https://www.pharmaexcipients.com/wp-content/uploads/2024/04/Evaluation-of-Printability-of-PVA-Based-Tablets-from-Powder-and-Assessment-of-Critical-Rheological-Parameters.pdf
  40. https://iasj.rdd.edu.iq/journals/uploads/2025/01/03/19dd66121e2a95a38262f33eeca15a5a.pdf
  41. https://www.sciencedirect.com/science/article/abs/pii/S2213343719303616
  42. https://www.researchgate.net/publication/264095241_Acid-Catalyzed_Hydrolysis_Reaction_of_Polyvinyl_acetate
  43. http://pdf.hanrimwon.com/journal.aspx?journal_code=POLYMERKOREA&journal_issue=03&journal_vol=029&kinds=JOU&pdf_file=PK29-3-0304.pdf
  44. https://pubs.acs.org/doi/10.1021/ed078p1370
  45. https://pslc.ws/macrog/radical.htm
  46. https://www.flinnsci.com/api/library/Download/8dcefc2345ef4072a3d0082316723ad8
  47. https://core.ac.uk/download/pdf/39181318.pdf
  48. https://www.researchgate.net/publication/281526601_Preparation_of_poly_Vinyl_alcohol_from_local_raw_material
  49. https://www.jinhetec.com/blog/analysis-of-global-and-chinese-polyvinyl-alcohol-industry-in-2023-93281.html
  50. https://prismaneconsulting.com/report-details/global-polyvinyl-alcohol-pva-market-study
  51. https://www.kuraray.com/global-en/news/2012/0605/
  52. https://patents.google.com/patent/US8697802B2/en
  53. https://www.elephchem.com/application-and-preparation-of-polyvinyl-alcohol
  54. https://www.sciencedirect.com/science/article/abs/pii/S0009250907008603
  55. https://dwsim.fossee.in/flowsheeting-project/download/project-file/469
  56. https://ijiet.com/wp-content/uploads/2015/06/43.pdf
  57. https://www.sciencedirect.com/science/article/abs/pii/S0022286023025620
  58. https://www.agilent.com/cs/library/applications/5991-2519EN_GPCpharma.pdf
  59. https://datavagyanik.com/reports/polyvinyl-acetate-pva-market/
  60. https://www.kuraray.com/global-en/news/2025/0925/
  61. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/polyvinyl-alcohol
  62. https://www.archivemarketresearch.com/reports/polyvinyl-alcohol-pva-powder-377860
  63. https://www.sekisui-sc.com/applications/textiles/
  64. https://www.industryresearch.biz/market-reports/polyvinyl-alcohol-market-113165
  65. https://pmc.ncbi.nlm.nih.gov/articles/PMC8072764/
  66. https://www.mdpi.com/2079-6412/13/11/1975
  67. https://www.sekisui-sc.com/blog/ceramics1/
  68. https://www.inchem.org/documents/jecfa/jecmono/v52je09.htm
  69. https://www.3dnatives.com/en/all-you-need-to-know-about-pva-for-3d-printing-270520224/
  70. https://www.monosol.com/about-pva/
  71. https://www.ncbi.nlm.nih.gov/books/NBK464344/
  72. https://ntrs.nasa.gov/api/citations/19790012957/downloads/19790012957.pdf
  73. https://www.mordorintelligence.com/industry-reports/polyvinyl-butyral-interalyers-market
  74. https://www.gminsights.com/industry-analysis/laminated-glass-market
  75. https://dorfketal.com/index.php/polyvinyl-formal-pvf/
  76. https://www.chemicalbook.com/ChemicalProductProperty_EN_CB3748800.htm
  77. https://www.schem.net/blog/difference-between-polyvinyl-butyral-pvb-resin-and-polyvinyl-alcohol-pva-resin_b72
  78. https://www.sciencedirect.com/science/article/abs/pii/S0014305713001304
  79. https://www.archivemarketresearch.com/reports/polyvinyl-butyral-72616
  80. https://cordis.europa.eu/article/id/454293-recycled-polymer-works-its-way-into-laminated-glass
  81. https://www.mdpi.com/2073-4360/17/3/317
  82. https://pubmed.ncbi.nlm.nih.gov/12504164/
  83. https://monographs.iarc.who.int/wp-content/uploads/2018/09/ClassificationsAlphaOrder.pdf
  84. https://www.cir-safety.org/sites/default/files/PVA.pdf
  85. https://www.fda.gov/files/food/published/GRAS-Notice-GRN-767-polyvinyl-alcohol.pdf
  86. https://www.fishersci.com/content/dam/fishersci/en_US/documents/programs/education/regulatory-documents/sds/chemicals/chemicals-p/S25473.pdf
  87. https://www.fishersci.com/store/msds?partNumber=AA41241&productDescription=keyword&vendorId=VN00024248&countryCode=US&language=en
  88. https://echa.europa.eu/substance-information/-/substanceinfo/100.008.350
  89. https://www.elephchem.com/pharmaceutical-grade-polyvinyl-alcohol
  90. https://pmc.ncbi.nlm.nih.gov/articles/PMC11342069/
  91. https://pmc.ncbi.nlm.nih.gov/articles/PMC7563362/
  92. https://www.researchgate.net/publication/282460847_Enrichment_and_isolation_of_microbial_strains_degrading_bioplastic_polyvinyl_alcohol_and_time_course_study_of_their_degradation_potential
  93. https://www.science.gov/topicpages/p/polyvinyl%2Balcohol%2Bdegradation.html
  94. https://www.kuraray-poval.com/further-news/lca-assessment-for-kuraray-poval-polyvinyl-alcohol-pvoh-products-manufactured-in-frankfurt-germany
  95. https://www.packagedsustainable.com/post/is-polyvinyl-alcohol-pva-biodegradable-or-does-it-cause-microplastics
  96. https://pmc.ncbi.nlm.nih.gov/articles/PMC8199957/
  97. https://www.polyva-pvafilm.com/a-news-recycling-and-disposal-considerations-for-pva-films.html
  98. https://pubs.acs.org/doi/10.1021/acssuschemeng.3c07435
  99. https://www.plasticstoday.com/biopolymers/dow-sources-bio-based-feedstock-for-us-plastics-production
  100. https://www.polyva-pvafilm.com/a-news-biodegradability-and-environmental-benefits-of-pva-films.html
  101. https://susproc.jrc.ec.europa.eu/product-bureau/sites/default/files/2025-02/Draft%2520ANNEX%2520III_Industrial_and_institutional_dishwasher_detergents_for_2nd_consultation_250221.pdf
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