酯端基型聚酰胺胺树形高分子对聚(3-羟基丁酸戊酸共聚酯)结晶性能的影响

采用不同比例G3.5酯端基类型的聚酰胺胺(PAMAM)树形高分子氯仿溶液与聚(3-羟基丁酸酯-co-3-羟基戊酸酯)(PHBV)树脂氯仿溶液进行共混并流延成膜，采用差示扫描量热分析、偏光显微镜以及拉伸和直角撕裂等方式对制备的PHBV/PAMAM复合膜进行表征。结果表明，随着PAMAM树形高分子的加入，PHBV/PAMAM复合膜的玻璃化转变温度（Tg）越来越明显，初步表明其韧性增强； G3.5 PAMAM树形高分子的加入，可使PHBV的结晶度由61.70 %先下降至24.02 %，并逐渐下降，最后至结晶消失； PAMAM树形高分子的加入可使PHBV的直角撕裂强度大幅度提高，最高可由8.90 kN/m提高到22.10 kN/m；当PAMAM树形高分子含量为2.0份时，增韧效果最好。

Effect of Ester-terminated Poly(amidoamine) Dendrimer on Crystallization Properties of Poly(hydroxybutyrate-co-hydroxyvalerate)

Ester-terminated poly(amidoamine) (PAMAM) dendrimer of generation 3.5(G3.5) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were blended in chloroform and casted into film. Properties of the film were characterized using differential scanning calorimetry, polarizing microscope, tensile tester, and right angle tearing tester. The results indicated that with the addition of PAMAM dendrimer, the glass transition temperature of the film became more distinct, indicating a greater toughness. The crystallinity of the PHBV/PAMAM film was much lower than that of neat PHBV (0~24.02 % vs 61.70 %). Moreover, the addition of PAMAM dendrimer considerably increased the tangential breaking strength of PHBV from 8.90 kN/m to 22.10 kN/m. The optimal toughening effect was observed with a PAMAM dendrimer content of 2.0 phr.