原位反应挤出制备聚乳酸与聚醚酯嵌段共聚物合金的性能研究

以0.35%(质量分数)的过氧化二异丙苯(DCP)为引发剂和2%(质量分数)的马来酸酐(MAH)为增容剂,通过原位反应挤出的方法制备了聚乳酸(PLLA)/聚醚酯嵌段共聚物(TPEE)合金。利用TG、差示扫描量热(DSC)、SEM等研究了其热性能和相形态,并测试了合金的力学性能和熔体流动速率。结果表明,在引发剂DCP的存在下,MAH的添加使得反应挤出制备的合金中PLLA与TPEE之间产生部分共价键连接而增加了相容性。合金的热稳定性、韧性随TPEE含量的增加而升高,但模量和强度下降。另外,不同TPEE含量的合金的熔体流动速率均高于纯PLLA和TPEE,表明在原位反应挤出过程中PLLA与TPEE均发生了一定程度的降解反应。同时,对合金的流变性能也进行了研究。

Properties of Poly(L-lactic acid) and Poly(ether-ester) Copolymer Alloy Prepared by In-situ Reactive Extrusion

Poly (L-lactic acid)(PLLA)/poly (ether-ester)copolymer(TPEE)alloys were prepared by reactive extrusion using 0.35wt% of dicumylperoxide (DCP)as initiator and 2wt% of maleic anhydride (MAH)as reactive compatilizer.Their thermal properties and morphologies were investigated by thermal gravimetric analyzer (TGA), differential scanning calorimeter (DSC)and SEM,and the mechanical properties and melt flow rates were also deter-mined.The results showed that miscibility of PLLA/TPEE alloys was improved due to the formation of a silk-like co-valent bonding link between PLLA and TPEE,which is a result of surface reaction in the presence of DCP and MAH. The thermal stability and toughness of the alloys increased with the addition of TPEE,but the strength and modulus decreased with the addition of TPEE.Meanwhile,the melt flow rates of the alloys were higher than that of neat PL-LA and TPEE due to the degradation of PLLA and TPEE during reactive extrusion process.In addition,rheology properties were also investigated.