price for polyvinyl alcohol HOPE WAY PVA HWF-20 for sale,price for polyvinyl alcohol HOPE WAY PVA HWF-20 exporters and manufacturers

Home >> Polyvinyl Alcohol(PVA) >> price for polyvinyl alcohol HOPE WAY PVA HWF-20

HOPE WAY POLYVINYL ALCOHOL

Introduction

PolyvinylAlcohol (PVA) is a water soluble and biodegradable synthetic polymer. It is adry solid, and is available in granule and powdered forms. Grades include bothfully hydrolyzed and partially hydrolyzed. PVA is an excellent adhesive withsuperior bonding strength, film forming and emulsifying properties. The film ofPVA exhibits outstanding resistance to oil, grease and solvents. In addition toits film forming property, it has excellent adhesion to both hydrophilic andhydrophobic materials. PVA has been extensively used in textile industry forwarp sizing and resin finishing; in paper industry for surface sizing andpigment coating; in the production of PVAc emulsion as protective colloid; inthe suspension polymerization of PVC as a dispersion agent; as binder for ceramics,magnet, foundry cores and pigments.

PVA is manufactured by polymerization of vinyl acetate monomer, byhydrolysis of the polyvinyl acetate. HOPE WAY PVA is produced in a wide rangeof hydrolysis and polymerization. In the partially hydrolyzed grades, 86-89mole% of acetate group is replaced by alcohol group. Likewise, in the fullyhydrolyzed grade, 98.0~99.0 mole % of acetate group is replaced by alcoholgroup.

IndividualPVA grade varies in molecular weight (degree of polymerization) and degree ofhydrolysis. In order to help our valued PVA users to choose the mostappropriate grade, HOPE WAY has defined HOPE WAY PVA grade as following:

HWF-17: Fully hydrolyzed PVA with degree of polymerization about 1700.

HWP-20: Partially hydrolyzed PVA with degree of polymerization about 2000.

The two-digit number indicates the degree of polymerization byone-hundredth; the higher the number, the higher degree of polymerization, sois the viscosity.

The most important properties which the majority of applications depend aredegree of polymerization and degree of hydrolysis. The degree of polymerizationis an expression of the size of polymer. The higher the degree ofpolymerization of polymer is, the bigger the size and the longer the length ofpolymer is. Similarly, the degree of hydrolysis is an expression of the ratioof hydrophilic alcohol group and hydrophobic acetate group.

The properties of PVA are summarized as follows.

1. Basedon degree of polymerization

■ The higher degree of polymerization of polymer is, the higher viscosity ofsolution and adhesion strength of film are.

■ The higher degree of polymerization of polymer is, the less water solubilityand the higher solvent resistance are.

■ The higher the degree of polymerization of polymer is, the higher tensilestrength of PVA film is.

■ The higher the degree of polymerization of polymer is, the less penetrationand softness of film is.

■ The higher the degree of polymerization of polymer is, the better protectiveability is.

2. Based on degree of hydrolysis- Dissolving properties

■ Fully hydrolyzed grade PVA (HWF type) can be easily dissolved in over 90°Cwater, but it only swells in room temperature water.

■ Partially hydrolyzed grade PVA (HWP type) can be slowly dissolved in roomtemperature water. But in normal uses, raising temperature to 90°C is necessaryfor saving dissolving time.

■ Super low hydrolyzed grade PVA (HWC type) can be dissolved in 25°C to 50°Cwater, according to their grades.

3. Characteristic of HWF type PVA

■ Good affinity to hydrophilic fiber such as cotton, rayon and paper.

■ Better water resistance film property than HWP type PVA film.

■ Viscosity is less stable in the condition of low temperature and high concentrationthan HWP type PVA.

■ Dissolving rate is slower than HWP type PVA.

4. Characteristic of HWP type PVA

■ Good affinity and cohesion power to hydrophobic fiber such as polyester,nylon, polyester /cotton blended and polyester/ rayon blended fiber.

■ Good compatibility with oiling agent.

■ Good solution viscosity stability.

■ Better protective colloid property than HWF type PVA

Previous:chemicals for textile industry Polyvinyl alcohol 2488

Next: price for polyvinyl alcohol HOPE WAY PVA HWF-17

Product Categories

Address :2th, No. 104, Jinshang Road, Huli, Xiamen,China.
Tel :+86 592 5255859
Fax :+86 592 5525425
E-mail:sales@sinopva.com
Quick Index : A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Polyvinyl Alcohol Application

Polyvinyl Alcohol Grades

Polyvinyl Alcohol Introduction