Effect of β‐nucleating agent on the crystallization, mechanical properties, and heat resistance of impact‐resistant propylene–ethylene copolymer

Abstract

In this study, β‐nucleated impact‐resistant propylene–ethylene copolymer (IPC) samples were prepared via melt compounding. The effect of β‐nucleating agents (β‐NAs: NT‐A and NT‐C) on the nonisothermal crystallization and melting behaviors of IPC was investigated by means of differential scanning calorimetry (DSC). Spherulitic morphology, mechanical properties and heat resistance of the samples were investigated. The nonisothermal crystallization kinetics was analyzed by Mo's method and the crystallization activation energy was calculated by Kissinger's method. The results show that the content of β‐crystals and the crystallization rate of the β‐nucleated IPCs are greater than those of the neat IPC, indicating that NT‐C is more efficient than NT‐A as a β‐NA. It is also found that the addition of β‐NAs decreases the size and increases the number of spherulites significantly. The Izod notched impact strength and heat deflection temperature (HDT) of IPC are also improved by β‐NAs, accompanied with marginal loss of tensile strength. It is found that the β‐α phase transition occurred during the HDT tests for β‐ nucleated IPCs. It is also indicated that Mo's method well describes the nonisothermal crystallization kinetics of the samples. The addition of β‐NAs remarkably decreases the activation energy of nonisothermal crystallization of IPC. J. VINYL ADDIT. TECHNOL., 24:E36–E47, 2018. © 2016 Society of Plastics Engineers