분야
hwp2.Objective
3.Theory
4.Apparatus & Reagents
5.Produce
6.Data & Result
7.Discussion
8.Reference
Synthesis of PVAc and PVA
2.Objective
PVA(poly vinyl alcohol) is prepared by hydrolysis of PVAc, which is synthesized by emulsion polymerization of vinyl acetate.
3.Theory
◇ Background
-PVA
Polyvinyl alcohol has excellent film forming, emulsifying, and adhesive properties. It is also resistant to oil, grease and solvent. It is odorless and nontoxic. It has high tensile strength and flexibility, as well as high oxygen and aroma barrier properties. However these properties are dependent on humidity, in other words, with higher humidity more water is absorbed. The water, which acts as a plasticiser, will then reduce its tensile strength, but increase its elongation and tear strength. PVA is fully degradable and is a quick dissolver.
-PVAc
Polyvinyl acetate, PVA, PVAc, poly(ethenyl ethanoate), is a rubbery synthetic polymer with the formula (C4H6O2)n. It belongs to the polyvinyl esters family with the general formula -[RCOOCHCH2]-. It is a type of thermoplastic. It should not be confused with the related polymer polyvinyl alcohol, which is called PVA also (PVAc could be considered a technically correct abbreviation for polyvinyl acetate and would aid in avoiding such confusion). Polyvinyl acetate is a component of a widely-used type of glue, referred to variously as wood glue, white glue, carpenter's glue, school glue or PVA glue.
1) http://en.wikipedia.org/wiki/Polyvinyl_alcohol
2) http://en.wikipedia.org/wiki/Polyvinyl_acetate
3) http://en.wikipedia.org/wiki/Suspension_polymerization
4) http://en.wikipedia.org/wiki/Bulk_polymerization
5) http://en.wikipedia.org/wiki/Emulsion_polymerization
6) http://en.wikipedia.org/wiki/Solution_polymerization
7) http://en.wikipedia.org/wiki/Transesterification
8) http://en.wikipedia.org/wiki/Potassium_persulfate
9) http://en.wikipedia.org/wiki/Sodium_lauryl_sulfate
10) http://en.wikipedia.org/wiki/Vinyl_acetate
11) http://en.wikipedia.org/wiki/Saline_water
12) http://en.wikipedia.org/wiki/Distilled_water
