Poly vinyl alcohol is completely water soluble and thus is used as a thickener in some suspensions and emulsions.
Repeating unit of pva poly vinyl alcohol is.
The repeat unit for poly vinyl alcohol pva is shown below.
It is colourless white and odorless.
It is commonly supplied as beads or as solutions in water.
Pva is unique among polymers chemical compounds made up of large multiple unit molecules in that it is not built up in polymerization reactions from single unit precursor molecules known as monomers.
Component of watersoluble edible film that may be used to form pouches containing pre portioned aliquots of 1 certain dry ingredients i e instant tea instant coffee hot chocolate mix flavored drink powder and whey protein supplement powder to be used by the consumer in preparing ready to serve foods and beverages at a.
As a novel biodegradable material poly vinyl alcohol pva starch st glycerol gl halloysite nanotube hnt nanocomposite films were prepared by solution casting at the hnt contents of 0 25 0 5 1 3 and 5 wt.
Water absorption capacity and water solubility of nanocomposite films were decreased remarkably by 44 24 and 48 05 respectively with increasing the hnt content from 0 to 5.
Poly vinyl alcohol is a synthetic polymer bearing repeating ch 2 ch oh units which is generally prepared from post polymerization reaction of a homopolymer obtained from a protected monomer such as vinyl acetate.
Although usually amorphous it can be drawn into a semicrystalline fiber.
Determine the number average molecular weight of this particular polymer.
Calculate the repeat unit molecular weight for pva.
This is the value with which the proportion of the vinyl alcohol unit in all the repeating units is indicated in mol.
Additionally when expressing the degree of hydrolysis using the repeating units m and n in figure 1 the degree of hydrolysis can be expressed as follows.
If the degree of polymerization of a particular pva is 2 000.
However the melting point of the crystallites is above the thermal degradation temperature.
Instead pva is made by dissolving another polymer polyvinyl.
Polyvinyl alcohol pva a colourless water soluble synthetic resin employed principally in the treating of textiles and paper.
Poly vinyl alcohol pvoh pva or pval is a water soluble synthetic polymer it has the idealized formula ch 2 ch oh n it is used in papermaking textile warp sizing as a thickener and emulsion stabilizer in pvac adhesive formulations and a variety of coatings.
Accordingly increasing attention is devoted to the preparation of environmentally compatible pva based materials for a wide range of applications.
Degree of hydrolysis mol m n m 100.
