Epoxidized linseed oil as a plasticizer for All-Cellulose Composites based on cellulose acetate butyrate and micronized pulp fibers

Abstract

All-Cellulose Composites (ACCs) with cellulose derivatives have been neglected in the composite industry due to their high brittleness, low impact strength, and flowability. Epoxidized vegetable oils are well-known plasticizers for several polymers and composites but have never been exploited on the production of ACCs. The present work investigates the potential of an epoxidized linseed oil (ELO) as a cost-effective additive to enhance the properties and processability of ACCs made with cellulose acetate butyrate (CAB) and micronized Eucalyptus pulp fibers. The thermo-mechanical characterization of the composites, obtained by melt-mixing, revealed that ELO significantly decreases the glass transition temperature (Tg) of the obtained composites without compromising their thermal stability. Moreover, an 84-fold improvement was achieved on the melt flow rate (MFR) with 30 wt% ELO, and growing amounts of this additive caused an augment on the elongation and flexural strains at break. High loads of ELO resulted also on a substantial improvement of the impact strength, with values raising from 5.3 ± 0.9 kJ.m−2 up to 29.5 ± 1.7 kJ.m−2. Furthermore, this eco-friendly plasticizer also led to higher water uptake values, as well as higher biodegradation rates than the non-plasticized ACCs. Therefore, these results evince a remarkable improvement on the ACCs processability, performance, and biodegradation upon addition of a bio-based and cost-effective plasticizer.