Decrystallization of cellulose under the influence of elastomer-assisted mechanical and mechanochemical shear

Abstract

Microcrystalline cellulose (MCC) was subjected to mechanical and mechanochemical shear in a rubber mixing milling. Nitrile rubber (NBR) and ethylene-propylene-diene monomer (EPDM) rubber were used to induce shear on cellulose during treatment. Solid-state interactions between N ,N-dimethylacetamide/lithium chloride (DMAc/LiCl) and cellulose particles were facilitated during mechanochemical shear. Fourier transform infrared spectroscopy, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy and swelling studies were carried out on MCC, DMAc/LiCl-treated MCC, MCC subjected to mechanical shear and DMAc/LiCl-treated MCC subjected to mechanochemical shear. Crystallinity and swelling behaviour of the untreated and merely DMAc/LiCl-treated MCC samples, in the absence of any shear, were found to be similar. However, when MCC was subjected to mechanical shear assisted by NBR and DMAc/LiCl-treated MCC subjected to mechanochemical shear assisted by EPDM, the resultant MCC samples exhibited significant reduction in their crystalline index with increased swelling. When DMAc/LiCl-treated MCC was subjected to mechanochemical shear assisted by NBR and mechanical shear alone on MCC, assisted by EPDM, did not exhibit any appreciable change in the crystalline index and swelling behaviour of the resultant MCC samples. While NBR-assisted mechanical shear was found to reduce crystallinity in untreated MCC, crystallinity in DMAc/LiCl-treated MCC was found to be reduced significantly with EPDM rubber-assisted mechanochemical shear.

Influence of micro crystalline cellulose on EPDM-based automotive sealing profile

“…Lavanya and Natchimuthu conducted a study on nitrile butadiene rubber (NBR)-EPDM-MCC to investigate decrystallization under the mechanical and mechano-chemical shear effect. 15 No considerable improvement was seen in the produced elastomer. In another study, George et al investigated the mechanical and thermal properties of nanosilica-filled EPDM-Kevlar fiber hybrid nanocomposites, and a higher tensile strength was observed.…”

Effect of cellulose-based fillers on vulcanized natural rubber

“…For this reason, among others, natural cellulose-based fillers are gaining attention in both research and industrial sectors, in addition to the excellent specific chemical and physical properties exhibited by such materials. Therefore, the development of low-density and environmentally friendly reinforcement fillers such as cellulose nanocrystals (CNCs) has been identified as a potential replacement for traditional fillers (Tian et al 2017;Phanthong et al 2018;Chawalitsakunchai et al 2019;Dittanet et al 2019;Lavanya and Natchimuthu 2019;Nie et al 2019;Tao et al 2019;Ali et al 2020).…”

Dispersion and vulcanization characteristics of nitrile rubber reinforced with N,N‐dimethylacetamide/lithium chloride treated silica

“…Similarly, DMAc/LiCl system, has been used effectively to dissolve cellulose by removing intermolecular hydrogen bonds between the chains. 26,27 DMAc/LiCl has also been found to be effective in reducing the hydrogen bonding in cellulose in solid state, using elastomers as shear transfer medium, 28,29 resulting in changes in cellulose morphology and decreased crystallinity.…”