HDPE／NBR共混物的超声行为研究

研究了不同丙烯腈含量的丁腈橡胶（ＮＢＲ）与高密度聚乙烯（ＨＤＰＥ）组成的共混物的超声行为，考察了共混物超声声速随组成变化的规律，首次发现不相容的ＨＤＰＥ／ＮＢＲ共混体系在丙烯腈含量较低时，共混物组成与声速仍呈线性关系。

INVESTIGATION ON ULTRASONIC BEHAVIOR OF HDPE/NBR BLENDS

It has established that compatibility of polymer blends can be examined via study on ultrasonic velocity through polymer blends.The further research works revealed that the ultrasonic velocity varies linearly with composition in compatible blends while the velocity deviates from linearity in incompatible polymer blends.The ultrasonic behaviors of various HDPE/NBR blends have been investigated, and the relationship of ultrasonic velocity vs.composition of the blends were obtained.It was found for the first time that the sonic velocity can vary linearly with composition for incompatible blends of HDPE/NBR as the content of AN of NBR is less than 25%(mass).This is not in accordance with previous conclusion.The morphological observation by SEM found that the blends was phase separated,and the FT-IR measurement proved there was no grafting between HDPE and NBR.The DMA results revealed that the NBR chains would favour entanglment with HDPE chains in amorphous area,and WAXD identified that there existed a partial order in HDPE amorphous area because of such entanglment. The fact that the NBR dispersed in HDPE in low composition can not be extracted out with dimethyl benzane revealed that the interface of two phase had good adhesion due to the entanglment of HDPE/NBR chains.This may be the cause of ultrasonic behavior of HDPE/NBR blends.