粉末NBR和超细碳酸钙填充粉末NBR硫化胶力学性能的研究*

以高分子树脂膜为包覆剂，采用凝聚共沉法制备非填充型粉末ＮＢＲ和超细碳酸钙填充粉末ＮＢＲ。研究了包覆剂及超细碳酸钙的用量对产物粒径及其硫化胶力学性能的影响。结果表明，当包覆剂用量为１０份时，粒径≤０９ｍｍ的产物占９９８％，加入超细碳酸钙后可进一步减小产物的粒径；极性适宜的包覆剂及超细碳酸钙对粉末ＮＢＲ硫化胶有显著的补强作用，故非填充型粉末ＮＢＲ及超细碳酸钙填充粉末ＮＢＲ均有良好的力学性能。扫描电镜分析表明，极性适宜的包覆剂与ＮＢＲ有一定的相容性，并以粒径约０５μｍ的微粒均匀分布于ＮＢＲ基体中；超细碳酸钙则以原生粒子和粒径≤０５μｍ的团粒存在，它在粉末ＮＢＲ中的分散性比块状ＮＢＲ／超细碳酸钙混炼体系有显著改善

Study on Mechanical Properties of Powdered NBR or Ultra-fine Calcium Carbonate-filled Powdered NBR Vulcanizates

The powdered NBR and ultrafine calcium carbonatefilled powdered NBR were prepared with coacervationcoprecipitation method by using polymeric resin as encapsulant.The influence of the encapsulant and ultrafine calcium carbonate levels on the particle size of product and the mechanical properties of vulcanizate was investigated.The results showed that the particle size of product would be decreased further by the addition of ultrafine calcium carbonate if 10 phr of encapsulant was used and the product with particle diameter 0.9 mm accounted for 99.8%;both unfilled powdered NBR vulcanizate and ultrafine calcium carbonatefilled powdered NBR vulcanizate gave good mechanical properties because the encapsulant with suitable polarity and the ultrafine calcium carbonate had the significant reinforcing effect on the powdered NBR vulcanizate.It was found by SEM that the encapsulant with high polarity was compatible to NBR and dispersed uniformly in NBR matrix in the form of microparticles with diameter equal t