Use of plasticisers for thermo-plasticising starch

(57) In the bottom of existence of the water of quantity in which summary book invention is determined experimentally, . From polyvinyl alcohol of 88*99.5% of the degree of saponification, are manufactured by acetal-izing and/or the acetal exchange reaction by an acid catalyst with the carbohydrate containing a carbonyl group or a putative carbonyl group. However, the degree of acetal-izing is related with the usage which expresses with the carbonyl equivalent per 100 Eq of vinyl alcohol, and uses 0.2*20 and the biodegradable graft copolymer which is 1*10 preferably as a plasticizer to thermoplasticity-izing of starch and/or a starch mixture.