Radical Graft Copolymerization of Vinylpyrrolidone onto Poly vinylalcohol

Radical Graft Copolymerization of Vinylpyrrolidone onto Poly(vinylalcohol) 

Safety precautions Before this experiment is carried out. Sect. 2.2.5 must be read as well as the material safety data sheets (MSDS) for all chemicals and products used. 

An initiator solution is prepared by dissolving 0.625 g of 2,2-azobis(2-aminopropene) dihydrochloride in 6 ml water.The solution is transferred under argon into a syringe. 

A standard apparatus (250 ml, three-neck round-bottom flask, thermometer, heating bath) is equipped with magnetic stirrer, reflux condenser, dropping funnel with pressure release, and one neck is sealed with a septum which can be used for thermometer inlet but also addition of initiator solution using a syringe the apparatus is flushed with argon. Under argon atmosphere one adds 8.3 g of a 30-wt% polyvinylalcohol aqueous solution (2.5 g of PVA, molar mass about 30,000 g/mol), 1/5 of the vinylpyrrolidone amount (4.5 g),and about 3 drops of the initiator. 

000 g/mol, e.g.,Luviskol K30from BASF AG) solution -I-1 g 10 wt% aqueous polyvinylalcohol solution (M about 30,000 g/mol) 

About 10 drops of solution A and B, respectively, are added dropwise to 30 ml of an acetone/ethanol mixture (2 1). While the xmgrafted mixture causes a visible clouding, the graft product is fuUy soluble. 

---

Example 3.51 Radical Graft Copolymerization of Vinylpyrrolidone onto Poly(vinylalcohol)... 

---