Improving reinforcement of natural rubber latex by introducing poly‐zinc dimethacrylate and sulfur vulcanizing system

Abstract

In this work, zinc dimethacrylate (ZDMA) was employed to reinforce natural rubber latex (NRL) and a new process was introduced. Polymethacrylic acid was prepared by emulsion polymerization of methacrylic acid (MAA), then mixed with ZnO in a different mole ratio (ZnO/MAA) and the mixture was noted as PZDMA. It was added to NRL and a traditional sulfur vulcanizing system was adopted simultaneously. The mechanical test results show that compared with the sample "NR," the tensile and tear strength are significantly improved by the addition of PZDMA. When 7 phr ZnO (NR-7A) are loaded, it can reach 25.1 MPa and 62.8 N/mm, which are higher than "NR" by 52.0% and 104.6%, respectively. While the strength of the NRL film reinforced only with PZDMA is quite limited. Detailed analysis by Fourier-transforms infrared spectroscopy, X-ray diffractometers, scanning electron microscopy, thermogravimetric, and dynamic mechanical analysis revealed that PZDMA is successfully formed and dispersed uniformly in NRL, PZDMA acts as a nanoparticle and ionic cross-linking agent, and the covalent cross-linking network is formed by a sulfur vulcanizing agent. The dual cross-linking network shows a synergistic effect on the reinforcement of NRL. The present work provides a process to reinforce NRL with adjustable mechanical properties.mechanical properties, natural rubber latex, poly-zinc dimethacrylate, reinforcement | INTRODUCTIONZinc dimethacrylate (ZDMA) can be easily polymerized and grafted to the polymer chain in the presence of peroxide, and has attracted great interest from researchers due to its excellent polymer reinforcement properties. [1] Hayes and Conard [2] reported for the first time that ZDMA was used as an additive for hydrogenated nitrile rubber (HNBR), and its abrasion resistance, tear strength, and high-temperature performance were significantly

Preparation of Poly(acrylic acid-co-acrylamide)-Grafted Deproteinized Natural Rubber and Its Effect on the Properties of Natural Rubber/Silica Composites

“…The TGA and DTG thermograms of DPNR, P10-DPNR, and P30-DPNR are presented in Figure 8 . It was observed that the DPNR decomposed within the temperature range of 336–476 °C [ 57 ]. For the P10-DPNR and P30-DPNR, the weight loss at 70–170 °C was attributed to the loss of water in the modified DPNR samples.…”