天然胶乳包覆聚苯乙烯刚性微粒对聚丙烯结晶的影响

Effects of Natural Rubber Coating PS Rigid Particles on Crystallization of PP

采用DSC、XRD分析方法研究了聚苯乙烯刚性微粒(XPS)和天然胶乳包覆聚苯乙烯刚性微粒(N-XPS)对聚丙烯(PP)结晶行为的影响。结果表明:XPS和N-XPS均可加快PP在高温区的成核速率,导致PP在较高的温度下提前结晶;它的存在也阻碍了PP球晶的生长速率,使总结晶度降低,相比较而言,其中N-XPS有更好的效果。XRD分析表明:在PP中添加2%的XPS或N-XPS,均可诱导PP形成β结晶,增加用量,β-PP结晶峰消失;PP/N-XPS试样中2θ=14.02°的α晶(110)峰明显比纯PP的要小这一事实,佐证了N-XPS阻碍了PP(α-110)晶面的生长,使其结晶度降低的结果。

The effects of the polystyrene rigid particles （XPS） and PS particles coated by natural rubber （N-XPS） rigid particles on the crystallization behavior of polypropylene （PP） were investigated by differential scanning calorimeter （DSC） and X-ray diffraction （XRD） experiments. Results indicated that XPS and N-XPS could accelerate nucleation rate of PP in high temperature region resulting in PP crystallizing in advance in higher temperature, but they resisted the spherulitic growth rate of PP, and made the total crystal degree of PP decreased. Compared with XPS, N-XPS had better effect. XRD analysis showed that the β crystal existed in PP by adding 2% of XPS or N-XPS and then the β-PP crystal peak disappeared with the XPS or N-XPS content increasing. The α crystal （110） peak at 2θ = 14. 02° in PP/N-XPS blends was more distinctly snmller than that in the neat PP, which proved that N-XPS resisted the growth of the PP （α- 110） crystal face to lower crystal degree.