聚酰胺胺改性碳纤维/尼龙复合材料制备及性能

Preparation and properties of polyamidoamine modified carbon fiber/polyamide composites

为改善碳纤维增强尼龙复合材料(CFRPA)的加工流动性和力学性能,采用聚酰胺胺(PAMAM)树枝状高分子作为改性剂,通过熔融共混制备出碳纤维(CF)增强尼龙66(PA66)复合材料。采用DSC、万能试验机和SEM分别对改性后PA66的结晶行为、CFRPA的拉伸性能及微观组织形貌进行测试表征。结果表明,添加PAMAM可以极大地改善PA66流动性,有效降低CFRPA熔融共混时的黏度。PAMAM添加量为PA66的1wt%时,PA66的结晶度最大(为12.75%)。熔融指数(MFR)提高至112 g/10 min,较未改性的PA66的MFR增长了814.47%。对应的不同CF含量的CFRPA熔融共混时的平衡扭矩均有所降低,且CF可均匀地分布在PA66基体中,当CF含量为40wt%时,CFRPA的拉伸强度最高,为118 MPa。

To improve the processing flowability and mechanical property of carbon fiber reinforced polyamide(CFRPA) composites, polyamide amine(PAMAM) dendrimer was used as flow modifier when the CFRPA was prepared from melt compounding. DSC, electromechanical universal testing machine and SEM were employed to characterize the crystallization behavior of the modified polyamide 66(PA66) and the mechanical properties, microstructure morphology of CFRPA, respectively. Results indicate that by the addition of PAMAM, the fluidity of PA66 can be significantly improved and the viscosity of CFRPA melt blends can be effectively reduced. When the addition of PAMAM is 1 wt% of PA66 matrix, a maximum crystallinity of 12.75% of PA66 is achieved. The melt flow rate(MFR)is increased to 112 g/10 min, which is 814.47% higher than that of the unmodified PA66. Correspondingly, the equilibrium torques of the CFRPA with different CF contents during melt blending are reduced, and CF can be uniformly dispersed in the PA66 matrix. CFRPA has a maximum tensile strength as high as 118 MPa with CF content of40 wt%.