One facile route to prepare high‐strength natural rubber through a green cardanol modification technology

Abstract

A new modification strategy of natural rubber (NR) with high efficiency and environmental protection is proposed to get a high‐strength natural rubber (HSNR) by wetly modifying the natural latex with cardanol emulsified by emulsifier fatty alcohol polyoxyethylene ether sodium sulfate (AES) first and then short‐term high‐temperature treatment. The obtained HSNR was characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. Moreover, the influences of the amount of cardanol on the crystallization behavior, processability, and physicomechanical properties were also studied. The results indicated that HSNR has a higher molecular weight, gel content, Mooney viscosity, initial plastic value, and elastic modulus, exhibiting good thermal stability and high glass transition temperature. Markedly, HSNR vulcanizates had excellent mechanical strength and thermo‐oxidative aging resistance when the optimum dosage of cardanol was 1 phr. Further discussion revealed that cardanol could effectively modify NR and enhance comprehensive properties by promoting the crosslinking of molecular chains of NR and introducing phenol, which contributed to the potential value in the application field of replacing ribbed smoked sheets.