Lignin as Alternative Reinforcing Filler in the Rubber Industry: A Review

Nor Anizah Mohamad Aini,Kannika Sahakaro,Nadras Othman,Nabil Hayeemasae,M Hazwan Hussin

doi:10.3389/fmats.2019.00329

Nor Anizah Mohamad Aini, Kannika Sahakaro + Show 3 more

Open Access

https://doi.org/10.3389/fmats.2019.00329

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Abstract

Lignin has a potential reinforcing filler and alternative to carbon black in rubber industry. This is due to cheaper materials, abundant with yearly renewable source, low weight, high biological efficiency and wide ecological adaptability. Utilization of bio-filler in rubber industry has increased more attention among the researchers due to increasing environmental concerns and toxicological effect of carbon black towards health and environment. This article is intended to summarize the current efforts in development of green and sustainable of rubber product. Instead of focused to silica and alternative rubber matrix like guayule and Russian dandelion, lignin also has potential as reinforcing filler and lead to development of competitive green rubber composites. Lignin has several special properties such as good mechanical, physico-chemical, biodegradability, antioxidant and excellent thermal stability. However, incorporation of lignin in rubber matrix is not a straightforward and needs to overcome with certain suitable solution because of the polarity of lignin molecules which contribute to strong self-interactions. Consequently, chemical modification of lignin is often used to improve the dispersion of lignin in elastomers, or compatibilizer is added to enhance interfacial of adhesion between lignin and rubber matrix. This review attempts to compile relevant knowledge about the performance of lignin-filled rubber composite from different approach such as mixing method, surface modification, hybrid filler etc. This study is expected to gain significance interest of researcher globally on the subject of lignin-based rubber composites and the advancement of development in green rubber product.

Highlights

Given the many applications of rubber in industrial parts such as hoses, tires, seals, cushions, etc., it should be acknowledged that many aspects need to be considered and understood
The main goal of this review is to focus on lignin-derived compounds as bio-renewable filler as well as the performance and properties of lignin-reinforced rubber composites
This technology contributed to savings in automotive fuel, since it reduced rolling resistance by approximately 20% compared to a tire reinforced by carbon black (Hall and Moreland, 2001; Niedermeier et al, 2002; Hilonga et al, 2012; Sarkawi et al, 2015)

Summary

INTRODUCTION

Given the many applications of rubber in industrial parts such as hoses, tires, seals, cushions, etc., it should be acknowledged that many aspects need to be considered and understood. Lignin offers great advantages such as high abundance, light weight, cost-competitiveness, biodegradability, and environmental friendliness In view of it being insoluble in water (hydrophobic) and stable in nature, achieving efficient transportation of water and nutrition in the cells of plant (Nordstrom et al, 2013), and having an antioxidant, antimicrobial, and biodegradable nature, along with its CO2 neutrality and reinforcing capability (Pouteau et al, 2003; Boeriu et al, 2004; Doherty et al, 2011; Bertini et al, 2012) it is an excellent alternative for the development of innovative polymer composite materials (Frigerio, 2014; Watkins et al, 2014).

14 Kraft pipe lignin NR

17 Kraft lignin

Findings

19 Sodium sulfate