聚己内酰胺-己内酯微球/PA6原位微纤化复合材料的制备及性能研究

Preparation and Properties Research of Polycaprolactam-caprolactone Microspheres/PA6 in Situ Microfibrillated Composites

原位微纤化是提高复合材料强度和韧性的有效方法,但传统原位微纤化材料是基于两相体系的不相容特点。为了探究在相容体系下,两相粘度比对微纤化行为及复合材料性能的影响,通过阴离子聚合制得聚己内酰胺-己内酯(P (CL-CLO))共聚微球,并与PA6切片于双螺杆挤出机中通过共混纺丝,得到P(CL-CLO)/PA6原位微纤化复合材料。分别考察了CLO含量、共混比和牵伸比对共聚微球和微纤的形貌以及P(CL-CLO)/PA6的性能影响。通过SEM观察到,CLO含量为25 wt%以下时,能得到形貌规则的P(CL-CLO)共聚微球。旋转流变仪测结果表明,通过调控CLO含量实现了P(CL-CLO)与PA6的粘度比在1.25~1.65之间调控。对微纤形貌的观察发现,粘度比为1.45~1.65时所形成的微纤尺寸均匀。同时当共混比为2:8、牵伸比为4时,微纤复合材料伸长率和断裂强度分别比纯PA6提高了31.6%和2.96%。这表明微纤与基体间有良好的界面作用力,实现了复合纤维的增强增韧。

In situ microfibrillation is an effective method to improve the strength and toughness of composites,but traditional in situ microfibrillated materials are based on the incompatible characteristics of two-phase systems.In order to investigate the effects of the two-phase viscosity ratio on the microfibrillating behavior and composite properties under the compatible system,in this paper,poly(caprolactam-caprolactone)(P(CLCLO)) copolymerized microspheres were fabricated by anionic polymerization,and P(CL-CLO)/PA6 in situ microfibrillated composites were obtained by blending and spinning with PA6 slices in a twin-screw extruder.The effects of CLO content,blending ratio and drafting ratio on the morphology of copolymerized microspheres and microfibers as well as the properties of P(CL-CLO)/PA6 were investigated respectively.It was observed by SEM that P(CL-CLO) copolymerized microspheres with regular morphology were obtained when the CLO content was 25 wt% or less.The results of rotational rheometry showed that the regulation of viscosity ratio of P(CL-CLO) to PA6 between 1.25~1.65 was achieved by controlling the CLO content.The observation of microfiber morphology revealed that the microfibers formed with 1.45~1.65 viscosity ratio were uniform in size.At the same time,when the blending ratio was 2:8 and the drafting ratio was 4,the elongation and breaking strength of the microfiber composites increased by 31.6% and 2.96% respectively compared with those of pure PA6.It indicated that there was a good interfacial force between microfiber and matrix,which realized the reinforcement and toughening of composite fiber.