不同熔体强度对聚乳酸微发泡行为的影响  

Effect of Microcellular Foams from Polylactic Acid of Different Melt Strength

作　　者：韩志忠[1] 张有忱[1] 杨卫民[1] 谢鹏程[1] 

机构地区：[1]北京化工大学机电工程学院,北京100029

出　　处：《塑料》2016年第5期49-52,63,共5页Plastics

基　　金：中央高校基本科研业务费专项资金资助(YS1403)

摘　　要：合适的熔体强度是取得良好发泡效果的关键。通过对熔体强度的聚乳酸(PLA)进行微发泡注射实验,对其发泡密度、泡孔尺寸及分布情况及常规力学性能进行了测试和表征。实验结果表明:不同的熔体强度会对聚乳酸的发泡行为产生不同的影响,熔融指数在11.2 g/10min时,得到PLA发泡制品最低密度值为0.0928 g/cm^3,平均泡孔直径为38.5μm,泡孔密度为2.08×106个/cm^2;随着熔体强度的降低,PLA发泡制品的平均泡孔直径先增大后减小,泡孔密度先减小后增大,PLA发泡制品的发泡密度值和常规力学性能呈现先减小后增大的变化趋势。对熔融指数为11.2 g/10min的PLA进行微发泡后具有良好的泡孔结构和综合力学性能。Suitable melt strength was the key to making better foaming. Through the different melt index （melt strength） of polylactic acid （PLA） microcellular injection molding, the foam density, the average cell size and distribution and the conventional mechanical properties were tested and characterized. The results showed that the different melt strength of the PLA would had different effects to foaming behavior. When the melt index was reached to 11.2 g/10min ,the minimum density of PLA foamed article was obtained to 0. 0928 g/cm3 ,the average cell diameter to 38.5 μm and the cell density to 2.08 × 106/cm2. With lower melt strength, the average cell diameter of PLA foam products was first increased and then decreased, the cell density was decreased first and then increased. The foam density and the conventional mechanical properties was showed the change trend that decreased first and then increased. The melt index 11.2 g/10min of PLA micro-foamed had good cell structure and mechanical properties.

关 键 词：熔体强度 熔体流动速率 聚乳酸 微孔发泡 泡孔结构 

分 类 号：TQ320.63[化学工程—合成树脂塑料工业] Q946.816[生物学—植物学]