Polyvinyl alcohol (PVA) is a multifunctional water-soluble polymer that is widely used in many fields due to its excellent film-forming property, adhesion, solvent resistance and biodegradability.
The wide application of PVA is due to its unique combination of properties: water solubility, film-forming property, adhesion, biocompatibility and degradability, which makes it continue to play an important role in the fields of industry, medicine and environmental protection.
1. Physical and chemical properties
Polyvinyl alcohol is a high molecular polymer, non-toxic, odorless, pollution-free, and has a white or light yellow flocculent, flaky or powdery solid appearance
The molecular formula of completely alcoholyzed polyvinyl alcohol: -(C2H4O)n
The molecular formula of partially alcoholyzed polyvinyl alcohol: (C2H4O)n-(C4H6O2)m
The true specific gravity of polyvinyl alcohol is 1.26~1.31
Polyvinyl alcohol has good thermal stability; polyvinyl alcohol is easily soluble in water; polyvinyl alcohol has good blending properties; polyvinyl alcohol and its film are resistant to most organic solvents such as oils, lubricants and hydrocarbons
2. Main uses
It is used for fiber processing, fabric pulp, adhesive production, production of architectural coatings, production of emulsion stabilizers and dispersants, and production of acetal derivatives. In addition, polyvinyl alcohol is also widely used in degradable films, protective colloids and soil improvers, seed and pharmaceutical coatings, inorganic and electronic product adhesives, water-based films, cosmetic additives, temporary protective films, etc.
The following are its main application areas and functions:
1>. Adhesive industry
Function: As the main component of water-based adhesives, it provides high bonding strength and environmental protection.
Application: Used for bonding wood, paper, textiles, packaging materials, etc., such as white latex. Its low toxicity and high viscosity make it particularly important in food packaging glue.
2>. Textile industry
Function: As yarn sizing and finishing agent, it enhances fiber performance.
Application:
Sizing: Improve yarn strength and wear resistance, reduce weaving breakage.
Finishing: As a temporary protective film or compounded with other resins, improve fabric wrinkle resistance and feel.
3>. Papermaking industry
Function: Improve paper physical properties and printability.
Application:
Surface sizing: Enhance paper water resistance and tear resistance.
Coating agent: Improve paper smoothness and ink absorption uniformity.
4>. Building materials
Function: As an additive to improve construction performance.
Application:
Cement/mortar modification: enhance adhesion, flexibility, and reduce cracking.
Building coatings: as a film former, improve adhesion, water resistance, and wear resistance.
5>. Medical field
Function: use biocompatibility and controlled degradability.
Application:
Drug carrier: used for sustained-release tablet coating or microspheres.
Medical hydrogel: make wound dressings or artificial joint lubricants.
Absorbable sutures: automatically degrade after surgery to avoid secondary surgery.
6>. Packaging materials
Function: environmentally friendly water-soluble and barrier applications.
Application:
Water-soluble film: used for laundry beads, etc. to reduce plastic pollution.
Coating materials: improve the oil and moisture resistance of packaging.
7>. Environmental protection field
Function: help pollution control and degradable material development.
Application:
Sewage treatment: as a flocculant to absorb heavy metals and suspended solids.
Degradable plastics: replace traditional plastics and reduce environmental pollution.
8>. 3D printing
Function: Utilize water-soluble support properties.
Application:
Support material: Temporary structure that is easy to remove in complex printing.
Bio-ink: Carry cells for printing biological tissues.
9>. Other fields
Cosmetics: thickener or film former (such as facial mask).
Electronics industry: temporary protective film or ceramic molding adhesive.
Agriculture: seed coating or soil water retainer.
