Effects of zinc isophthalate on the crystallization and crystal transformation behavior of polybutene alloy

Abstract

The slow crystallization rate and crystal transformation restrict the application of PB-A (PB blended with 2-3wt% polypropylene). This paper investigated the effects of zinc isophthalate (ZnIA) on the crystallization and crystal transformation behavior of PB-A by means of DSC, POM, XRD and Flash DSC. The results showed that addition of ZnIA raised the crystallization peak temperature from 71.1 ℃ to 82.8 ℃ and decreased the half crystallization time from 818 s to 160 s at the content of 0.2wt%. It also reduced the spherulites size dramatically according to the images of POM. The survey conducted by Flash DSC showed that the formation of amorphous phase was retarded by the addition of ZnIA as cooling rate increasing and as a result, the crystallinity of PB-A was raised from 50.0 to 56.1% with 0.2wt% ZnIA added. Moreover, the improvement on crystal transformation caused by ZnIA could be owing to the increase in crystallization temperature which leads to the enhancement of internal thermal stress and shortened nucleating process as well before the growth of form I. In conclusion, Znic Isophthalate is a kind of effective and multifunctional nucleating agent for PB-A and this study is beneficial to understand the mechanism of crystallization as well as the crystal transformation for PB-A.

Effects of nucleating agents on the II–I transition of iPB-1

“…22,28,29 Fantinel 50 found that nano-montmorillonite not only acted as a nucleating agent by increasing the melt crystallization temperature of form II, but also accelerated the subsequent II–I transition at room temperature. Similar experimental observations have been reported after addition of ZnIA, 51 MWCNT, 52 or β-NA. 53 Kaszonyiova 29,54 further extended their work on processes of melt-II, III–I and III–II transitions of iPB-1.…”