Effect of Binder Coatings on the Fracture Behavior of Polymer–Crystal Composite Particles Using the Discrete Element Method

Huabin Wang,Yuchen Guo,Gaoyang Hu,Bo Zhou,Jianmei Li

doi:10.3390/coatings11091075

Abstract

Polymer–crystal composite particles formed by crystals coated with binders are widely used in the fields of medicine, energy, the chemical industry, and civil engineering. Binder content is an important factor in determining the mechanical behavior of composite particles. Therefore, this study aimed to investigate the underlying effect of binder coatings in the fracture micromechanics of polymer–crystal composite particles using the discrete element method (DEM). To achieve this objective, realistic particle and crystal shapes were first obtained and reconstructed based on X-ray micro-computed tomography (μCT) scanning and scanning electron microscope (SEM) images. A series of single particle crushing tests and DEM simulations were conducted on real and reconstructed polymer–crystal composite particles, respectively. Based on the experimental and DEM results, the effect of binder coatings on the crushing strength and crushing patterns of polymer–crystal composite particles was measured. Moreover, the micromechanics of the development and distribution of microcracks was further investigated to reveal the mechanism by which binder coatings affect polymer–crystal composite particles.

Highlights

Polymer–crystal composite particles formed by crystals coated with binders are widely used in the fields of medicine [1], energy [2,3], the chemical industry [4,5], and civil engineering [6,7]
The polymer–crystal composite particles were produced by a kneading granulation method, in which melamine crystals (C3 N6 H6 ) were coated with fluorine rubber (F2311) binders [47]
To eliminate the effect of the loading rate, a related analysis was implemented in our previous study [46], which was consistent with the results verified by Sheng et al [41] and Lv et al [55]

Summary

Introduction

Polymer–crystal composite particles formed by crystals coated with binders are widely used in the fields of medicine [1], energy [2,3], the chemical industry [4,5], and civil engineering [6,7]. To optimize binder content, it is critical to understand the macro-mechanical behavior and micro-fracture mechanisms of these composite particles during the loading process. The interfacial fracture mechanism of composite materials is a topical issue, and many mechanical test methods have been proposed to evaluate the adhesion of coatings, including the Brazil split test [14], the indentation test [15], the double cantilever beam test [16], and the four-point bend test [17]. The uniaxial compression test [7] and triaxial compression test have been more widely used [12,13,18]

Objectives

Methods

Results

Conclusion