Influence of modified biopolymers on thermal properties and biodegradation processes of carboxylated nitrile-butadiene (XNBR) nanocomposities

Abstract

The presented study includes a comparison of the effect of fillers used in carboxylated nitrile butadiene rubber XNBR on the properties of the obtained polymer materials. Fillers used in this study originated from the tanning industry waste: cattle hair keratin, enzymatic hydrolyzate of cattle hair keratin and condensate of enzymatic hydrolyzate of cattle hair keratin. The use of commonly found in nature phyllosilicates allows to obtain nanocomposites. That is why in the presented study we used different mass fraction of layered silicate-montmorillonite. The dispersion of silicates in polymer matrices can be influenced by their physical and chemical modifications that lead to changes in the properties of the polymer matrices themselves. In the presented study the kinetics of vulcanization of elastomer blends was investigated, and the obtained XNBR rubber vulcanizates were analyzed for mechanical, optical, rheological, thermal analysis and their resistance to accelerated thermo-oxidative aging (S) and susceptibility to biodegrade were tested. The produced elastomer composites may be used in the rubber industry in the assortment of various types of washers, elastomer seals or conveyor belts-materials that often work under elevated temperature conditions. Therefore, it seems advisable to understand the thermal properties of this type of materials, eg for suitability in real conditions. Therefore, Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Oxygen Index (IO) analyzes have been carried out, showing that different mechanisms of decomposition occur in layers of fiber-enriched polymer composites than unrecoverable ones. The modified keratin also slightly decreases the glass transition temperature. In addition, the presence of a modified keratin in the XNBR elastomer structure increases the composites compliance with the biodegradation process.

Recent development of biodegradable synthetic rubbers and bio-based rubbers using sustainable materials from biological sources

“…The activity of enzymatic hydrolysate of keratin was investigated in sulphur cured system with different additional llers, poly(vinyl alcohol), (PVAL) and montmorillonite (MMT) clay by Prochoń et al in the year 2015 and 2020, respectively. 84,85 Generally, the MMT-lled samples have higher TS, while EB and hardness are comparable to PVAL-lled samples at the same amount of keratin llers. At 10 phr keratin hydrolysate, 3.2% and 5.2% in TS reinforcement were observed in PVAL-lled and MMT-lled samples, respectively.…”