光/生物降解塑料薄膜制备及其性能研究

以玉米淀粉、低密度聚乙烯和线型低密度聚乙烯为主要原料,制得光/生物降解塑料薄膜,所得降解薄膜中淀粉质量分数约为30%,厚度约为20 μm.研究结果表明:吹膜料的流变性能接近聚乙烯,为剪切变稀的假塑性流体,可用通用塑料加工设备加工;该薄膜的力学性能接近纯聚乙烯薄膜,并具有较好的光降解性能;薄膜经紫外光照射或曝露在户外均可发生明显降解,其降解产物中含有羰基和不饱和碳-碳双键的聚合物.

Preparation and study on properties of photo-biodegradable plastic films

Photo-biodegradable plastic films containing 30 wt% of corn starch with thickness of about 20 fan were prepared by using corn starch, low-density polyethylene(LDPE) and linear low-density polyeth-ylene(LLDPE) as main materials. The processing properties of master-batch and the blend for blowing films were investigated. The rheological properties of the blend for blowing films were similar to that of LDPE, the mixture of master batch and LLDPE was pseudo-plastic fluid and could be processed by usmg classical plastic machines. The mechanical properties and photo-degradation properties of the films were also studied. The experiment results showed that the mechanical properties of the films approximated to that of LDPE film, and the films had good photo-degradation properties. After 15 days of exposure to ultraviolet light, some lower molecular weight polymers with carbonyl group or carbon-carbon double bond were detected in the degraded films.