以聚对苯二甲酸丁二醇酯(PBT)与双酚A型聚碳酸酯(PC)为基体、氧化铝(Al2O3)作为导热填料,通过熔融共混法制备了PBT/PC/Al2O3导热复合材料,采用亚磷酸三苯酯(TPPi)作为酯交换反应抑制剂调节材料中树脂基体的相态结构,并通过红外光谱分析(FTIR)、激光导热仪、扫描电子显微镜(SEM)、示差扫描量热仪(DSC)及力学性能测试仪等对材料中的酯交换反应、导热性能、相态结构、结晶参数及力学性能进行了表征.实验结果表明,TPPi的加入可有效抑制体系中酯交换反应的发生,使PBT/PC共混物的相态结构改变,进而对填料的分布状态产生影响.当PBT/PC配比为1/1时,向其中加入1 wt%的TPPi可使体系的相态结构趋向于形成双连续相态结构,并有效提升材料的导热系数;在该体系中加入60 wt%的Al2O3后,材料的导热系数达到0.89 W/(m·K),相对于未加入TPPi的相同体系提升了13%.
Thermally conductive composites based on Al2O3-filled poly( butylene terephthalate) / bisphenol-A polycarbonate( PBT / PC) blends were prepared with a melting mix technique by use of twin screw extruding.Triphenylphosphite( TPPi) as an inhibitor was used to suppress the transesterification between PBT and PC.The transesterification,thermally conductive property,phase structure,crystallization parameters and mechanical properties of the materials were characterized by Fourier transform infrared spectroscopy( FTIR),laserflash thermal analysis,scanning electron microscopy( SEM),differential scanning calorimetry( DSC) and mechanical properties tester,respectively. Experimental results show that TPPi can effectively suppress the transesterification; by this,the phase structure of the blend changed and the distribution of the fillers was also influenced. With 1. 0 wt% of TPPi loading in PBT / PC( 1 /1),the co-continuous phase structure formed and the thermal conductivity of the blend improved effectively. After adding 60 wt% of Al2O3 filler in the blend system with 1. 0 wt% TPPi,the thermal conductivity of the composite reached to 0. 89 W /( m·K),which improved by 13% than that of the system with no TPPi.