Silanized Silica-Encapsulated Calcium Carbonate@Natural Rubber Composites Prepared by One-Pot Reaction.

Yao Yu,Junyi Zhang,Hongzhen Wang,Zhenxiang Xin

doi:10.3390/polym12112668

Abstract

This article demonstrates the one-pot reaction, an efficient and environmentally friendly organic synthesis method, utilized to prepare the silanized silica-encapsulated calcium carbonate@natural rubber composites (SSC@NR), following first mixing the calcium carbonate (CaCO3) solution, silica (SiO2) sol solution and a small amount of Si-69 solution, to modify the surface of CaCO3 particles, and then wet mixing with natural rubber latex. The obtained silanized silica-encapsulated calcium carbonate (SSC) particles were tested by TGA, FTIR and XRD, to substantiate the effect of surface modification. Moreover, the effects of the amount of SSC on the Mooney viscosity, curing characteristics, physical and mechanical properties and dynamic mechanical properties of the SSC@NR were investigated. The results show that the surface of modified CaCO3 is effectively coated with SiO2 particles by means of physical and chemical combination, to achieve the effect of surface coating. When the optimum amount of SSC filler is 40 phr, the SSC can form better physical adsorption and chemical combination with the NR molecular chains and can be evenly dispersed in the rubber matrix, resulting in the conspicuous improvement of physical and mechanical properties, such as the tensile strength, tear strength, elongation at break and abrasion resistance. Meanwhile, the compound with SSC has preferable processability and dynamic mechanical properties.

Highlights

Calcium carbonate (CaCO3 ) is a kind of widely used inorganic chemical raw material.In recent years, due to the rapid development of rubber industry, plastic industry, coating industry, building materials and paper industry, the development of calcium carbonate industry has been promoted correspondingly [1,2,3,4]
Through a facile, efficient and environmental one-pot reaction, silanized silicacompatibility and dispersion of the silica-encapsulated calcium carbonate (SSC) in the rubber matrix are greatly improved and that they have encapsulated calcium carbonate (SSC) particles could be fabricated through the mixing of CaCO3 more binding and adsorption with the natural rubber molecular chain
With the increase solution, neutral silica sol solution and Si-69 solution, and wet-mixed SSC with natural rubber of the content of SSC, the Payne effect has been strengthened, which indicates that too many fillers latex, to obtain silica-encapsulated calcium carbonate@natural rubber composites (SSC@NR) composites

Summary

Introduction

Calcium carbonate (CaCO3 ) is a kind of widely used inorganic chemical raw material. In recent years, due to the rapid development of rubber industry, plastic industry, coating industry, building materials and paper industry, the development of calcium carbonate industry has been promoted correspondingly [1,2,3,4]. For the selected neutral silica sol solution, the thermal motion of the sol particles will aggravate the Brownian motion at a relatively mild temperature (80 ◦ C), which will increase the collision probability between particles, resulting in the instability of sol system and the coagulation of SiO2 particles on the surface of CaCO3 particles to form a dense silica coating. This experimental method has the characteristics of low energy consumption and environmental friendliness, and it provides the feasibility for practical production in industry

Materials

Experimental Variables

Characterization and Testing

The Chemical Structure and Microstructure of SSC

Conclusions