Synergistic Cross-linking and Reinforcing Enhancement of Rubber Latex with Cellulose Nanocrystals for Glove Applications

Abstract

The effect of cellulose nanocrystals (CNCs) on the reinforcing, cross-linking, and solvent barrier properties of lightly cross-linked natural rubber (NR) latex films for dipped goods applications were investigated. Predispersed CNCs, activating, and curing agents were mixed with natural rubber latex and allowed to mature for 2 h. Films were then prepared from the matured latex via dipping and solvent casting processes. The incorporation of CNCs in the NR latex led to remarkable improvement in tensile strength and modulus with progressively thinner films. An increase in the cross-linking density of the rubber films were observed as a result of the incorporation of CNCs, which was observed from proton nuclear magnetic resonance analysis, and toluene swelling studies. This was likely attributed to an enhanced dispersion of the zinc oxide (ZnO) used as a cross-linking activator as observed from electron dispersive X-ray spectroscopy (EDX). A possible mechanism for the improved dispersion of ZnO in the latex in the presence of CNCs was the formation of Zn–CNC complexes. Higher cross-linking densities also led to lower water absorption over a prolonged time period. The nanocomposite thin films showed low permeability to a nonpolar solvent vapor, such as tetrahydrofuran (THF), but increased permeability to water vapor. A practical application of the observed barrier properties in dipped rubber goods could be in gloves, where permeation of perspiration from hands, is allowed while preventing the passage of nonpolar solvents.

Facile Synthesis and Characterization of Palm CNF-ZnO Nanocomposites with Antibacterial and Reinforcing Properties

“…The thermal degradation of NR/CNF and NR/CNF-ZnO showed a slight decrease in the degradation onset temperature (Figure 7C). Similar curves have been documented regarding an NR network with CNF, where there was a reduction in the weight loss before the main NR degradation could be observed [50]. The decline of the degradation onset temperature could be ascribed to the lower onset degradation of cellulosic fibers compared to NR [51].…”

“…The peak shifted from 352 • C for neat NR to 364 • C for NR/CNF-ZnO. The improved degradation temperature can be attributed by the partial shielding of the rubber network by cellulosic fibers and the increased amount of cross-links facilitated by the presence of ZnO [50]. The ability of ZnO to serve as a common activator in the rubber curing process and a reinforcing agent in the NR polymer network [52] as well as having excellent heat resistance properties contributed to the enhanced tensile strength and thermal stability of the NR/CNF-ZnO composite film.…”

“…network with CNF, where there was a reduction in the weight loss before the main NR degradation could be observed [50]. The decline of the degradation onset temperature could be ascribed to the lower onset degradation of cellulosic fibers compared to NR [51].…”

Propolis and Organosilanes as Innovative Hybrid Modifiers in Wood-Based Polymer Composites

“…For this reason, it is essential to introduce certain modifications in order to improve interface interactions in the composite system. Various methods are used to enhance compatibility between lignocellulose fillers and polymer matrices, e.g., chemical modification [ 4 , 5 , 6 ], surface grafting of polymers onto fillers [ 7 ], introduction of compatibilisers such as maleated polymer [ 8 ], and treatment with coupling agents [ 9 , 10 , 11 , 12 ].…”

An Efficient and Sustainable Approach to Prepare Carboxylated Cellulose Nanocrystals for Rubber Reinforcement Featuring Dual Crosslinking Networks

“…al, since then plenty of reports about rubber/CNCs composites emerge (Eslami et al 2020 Rachel Blanchard et. al reported that the incorporation of CNC-OSO 3 H effectively improved the crosslinking density, tensile strength and modulus of the rubber latex for the application in dipped goods (Blanchard et al 2020). However, the poor heat resistance of CNC-OSO 3 H caused by sulfonate group and relatively low chemical reactivity remain a problem which cannot be ignored (Jiang et al 2010; Wang et al 2007; Roman et al 2004).…”