超高分子量聚乙烯/聚乙烯蜡共混物的流变性能研究

Study on Rheological Properties of UHMWPE/PE-Wax Blends

通过熔融共混法制备了超高分子量聚乙烯/聚乙烯蜡（UHMWPE/PE-wax）共混物,采用振荡频率扫描与时间扫描模式研究了PE-wax与UHMWPE的解缠结情况。结果表明：UHMWPE的解缠结速度由PE-wax和UHMWPE的分子量决定,PE-wax或UHMWPE的分子量越低,解缠结速度越快;共混物的模量由UHMWPE用量、分子量及其解缠结程度共同决定,UHMWPE用量越大、分子量越高或解缠结程度越高,共混物的模量越高;UHMWPE在剪切作用下逐步进行解缠结,当达到缠结平衡时,其模量达到最大值。通过研究PE-wax对UHMWPE的改性机理,为UHMPWE的加工提供借鉴。

Ultra high molecular weight polyethylene/polyethylene wax（UHMWPE/PE-wax） blends were prepared by melt blending. The entanglement of PE-wax and UHMWPE was studied by the mode of oscillating frequency scanning and time scanning. The results show that： The entanglement speed of UHMWPE is determined by the molecular weight of PE-wax and UHMWPE. The lower the molecular weight of PE-wax or UHMWPE, the faster the entanglement speed is. The modulus of the blends depends on the amount of UHMWPE, the molecular weight and the degree of entanglement. The greater the amount of UHMWPE, the greater the molecular weight or the higher the degree of entanglement, the higher the modulus of the blends. The lower molecular weight of PE-wax and the molecular weight of UHMWPE had the faster disentanglement process. The modulus of the mixture was determined by the concentration and molecular weight of UHMWPE, the degree of disentanglement of UHMWPE. The higher concentration of UHMWPE and the greater molecular weight of UHMWPE, or the greater the degree of disentangling had higher the mixing modulus. UHMWPE is gradually tangled under shear. When the entanglement balance is reached, its modulus reaches the maximum. Through studying the modification mechanism of PE-wax on UHMWPE, it can provide reference for UHMPWE processing.