淀粉/聚乙烯醇全降解缓释塑料薄膜的制备与性能研究

聚乙烯醇(PVA)溶解后与淀粉(St)共混,同时加入增塑剂丙三醇、交联剂甲醛,反应结束后将包膜液流延成膜。考察了m(St)∶m(PVA)、反应温度、丙三醇用量、甲醛加入方式、甲醛用量、反应时间对薄膜性能的影响,并表征了薄膜的结构。结果表明:当m((St)∶m(PVA)=7∶3、反应温度为90℃、w(丙三醇)=3%(占St、PVA、纯水质量之和的质量分数)、甲醛一次性加入、w(甲醛)=2%、反应时间为1 h时,制得的塑料薄膜拉伸强度、断裂伸长率较大,吸水率和透NH4+率均较低,共混体系的相容性好。

Preparation and properties of starch/polyvinyl alcohol full-degradable plastics membrane

Polyvinyl alcohol（PVA）dissolved in hot water was blended with starch（St）in the presence of plastifier glycerol and crosslinking agent formaldehyde.The reaction product was then made into membrane by casting method.The effects of the mass ratio of the St to PVA,the contents of glycerol and formaldehyde,the reaction temperature and time on the mechanical properties of the membrane were studied,and the structure of the membranes were characterized.The results showed when the mass ratio of St/PVA was 7∶3,the content of glycerol was three percent,the content of form aldehyde was two percent,the reaction temperature was 90℃ and the reaction time was 1h,the formaldehyde was added once,the elongation at break and the tensile strengths of the membrane were high,the water absorption rate and the transmissivity rate of ammonium were low,the compatibility of the membrane was very good.