摘要
通过溶液复合制备了聚丁二酸丁二醇酯(PBS)/氨基笼型低聚倍半硅氧烷(POSS)纳米复合材料,并研究了POSS的加入对其微观结构、晶体结构、结晶行为、球晶形态和球晶生长速率、力学性能和热稳定性等方面的影响.扫描电镜观察POSS能够均匀纳米级地分散在PBS基体中,呈现良好的界面作用.X-射线衍射仪测试表明加入POSS不影响基体PBS的晶型,且POSS在基体中以晶体形态存在.差示扫描量热测试显示加入POSS反而降低了非等温结晶温度,延长了等温结晶时间,表明POSS的成核能力非常有限,且POSS的加入阻碍了PBS链段的运动,偏光显微镜观察POSS降低了PBS的球晶生长速率.力学性能测试表明POSS提高了PBS的杨氏模量和储能模量,增强效果不显著,降低了PBS的断裂伸长率,提高了PBS的玻璃化转变温度.POSS分解温度低于PBS,但不影响基体PBS的热稳定性.综上实验结果分析,POSS分子上的氨基与PBS链段上的羰基形成较强的分子间氢键作用,以及POSS的笼型结构起物理交联点作用在PBS/POSS纳米复合材料中形成三维网络结构,是POSS影响PBS的结晶行为和力学性能的主要原因.
The poly（butylene succinate ） （ PBS ） and aminopropylisobutyl polyhedral oligomeric silsesquioxanes （POSS） nanocomposites were prepared by solution-casting method. The effects of POSS on the microstructure, crystal structure, crystallization behavior, spherulitic morphology and spherulite grow rate, mechanical properties and thermal stability of PBS/POSS nanocomposites were investigated with various techniques. Scanning electron microscope measurements revealed that POSS particles were well-dispersed uniformly on the nanoscale in the PBS matrix and had a good interfacial interaction with PBS chains. Wide- angle X-ray diffraction patterns showed that the POSS molecules are able to crystallize in PBS matrix,but do not affect the crystalline structure of PBS matrix. Differential scanning calorimetry results indicated that the incorporation of POSS particles into PBS matrix,unexpectedly, decreased the crystallization temperature during nonisothermal melt crystallization and prolonged the crystallization time during isothermal crystallization. The nucleation effect of such POSS on the crystallization of PBS is extraordinary limited; furthermore,it hindered the motion of PBS chains and decelerated the spherulite growth rate, as confirmed by polarized optical microscopy. Mechanical properties were evaluated by Instron and dynamic mechanical analysis. The Young＇ s modules and storage modules of the nanocomposites were enhanced relative to PBS by the addition of POSS, however, the tensile strength was not much improved and the elongation at break was reduced for the nanocomposites. Glass transition temperature （ Ts） of the PBS/POSS nanoeomposites increased slightly with increasing POSS content,which indicated that the molecular mobility of amorphous PBS chains was constrained in the nanocomposites. The above results indicated that the retarded crystallization of PBS and the variation of mechanical properties of the nanocomposites in the presence of POSS were ascribed the stronger hydrogen- bonding interactions between the POSS molecules and the PBS matrix as well as the network formation based on the POSS physical crosslinking points in the PBS/POSS nanocomposites.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2013年第10期1253-1261,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号31000427)
中央高校基本科研业务费(基金号DUT12JB09)资助项目
关键词
聚丁二酸丁二醇酯
笼型低聚倍半硅氧烷
纳米复合材料
阻碍结晶
Poly （ butylene succinate） , Polyhedral oligomeric silsesquioxanes, Nanocomposites, Retarded crystallization
