Effect of N,N′‐diphenyl adipamide on the formation of the β‐crystalline form in isotactic polypropylene

Abstract

ABSTRACT:The polymorphic compositions and mechanical properties of isotactic polypropylene (iPP) samples nucleated by a selective b-nucleating agent [N,N 0 -diphenyl adipamide (DPA)] were investigated with wide-angle X-ray diffraction, polarized light microscopy, scanning electron microscopy, and mechanical tests. It was found that b-phase crystals emerged with the addition of DPA, and the relative proportion of the b-crystalline form reached the maximum value of 0.97 with the addition of 0.1 wt % DPA. The curved lamellae in the b spherulites were like flowers. The b spherulites were etched more easily than a spherulites because amorphous regions were distributed inside the b spherulites. The Izod notched impact strength increased sharply with the addition of DPA and attained the maximum value of 7.30 kJ/m 2 (the value of blank iPP was 3.13 kJ/m 2 ) with the addition of 0.1 wt % DPA. An analysis of the misfit factors between DPA and b-iPP showed that b-iPP could epitaxially crystallize on the DPA crystal well.

Nonisothermal crystallization and multiple melting behaviors of β‐nucleated impact‐resistant polypropylene copolymer

“…Therefore, in this work, we introduced a highly effective β‐form nucleating agent (β‐NA; an aryl amide compound with the trade name TMB‐5) into IPC to further investigate the crystallization behavior of IPC. It has been proven that TMB‐5 is a highly effective β‐NA for the crystallization of isotactic PP, and the nucleation efficiency is comparable to values reported in the literature 20–27. Similarly, both the nucleation efficiency of TMB‐5 and the supermolecular structure of iPP are determined by the concentration of β‐NA 28–32.…”

Crystal structure and melting behavior of homo-polypropylene and heterophasic ethylene–propylene copolymer after long time heat treatment

“…Due to its perfect performance, b-iPP has its wide applications like in toughened plastic products, pressurized pipe system, micro-porous fibers and so on. In the past two decades, the crystalline structure, crystallization characteristics, melting behavior as well as properties of b-iPP formed have attracted many researchers' interests [10][11][12][13].…”

Self‐organization of micro reinforcements and the rules of crystal formation in polypropylene nucleated by non‐selective nucleating agents with dual nucleating ability

“…[3,10,27] There are also numerous NAs, which induce the formation of the β-modification because its impact resistance is significantly larger compared to that of the α-form. [25,[28][29][30][31][32][33][34][35][36][37][38][39] Several novel β-NAs are soluble in the polymer melt in order to achieve good homogeneity, however, β-NAs are not always completely selective to one of the modifications and mixed polymorphic structure is formed in their presence. [29,40] This effect is designated as "dual nucleating ability", which term was introduced in our earlier publication.…”