A comparison of natural rubber latex and polyethylene glycol as fiber carriers in melt-compounded polylactic acid/cellulose microfibril composites

Abstract

This article relates to the melt-processing and properties of polylactic acid (PLA) reinforced with cellulose microfibrils (CMFs). The CMFs with diameters of 20-80 nm and lengths in the order of microns were isolated from wood sawdust. The purpose of the present study was to find a simple method to overcome the problems associated with feeding and aggregation of the nanoscale fibers in PLA melt. Two fiber carriers were compared, that is, natural rubber (NR) latex and polyethylene glycol (PEG) with a molecular weight of 4000 g mol À1. The results showed that with the aid of carrier, CMFs were successfully dispersed in the composites, enabling the strong reinforcing action of the fibrils to be realized. The type of carriers used had significant effects on the final properties of the PLA composites. Dynamic mechanical analysis results showed an eightfold improvement in modulus at elevated temperature (90 C) for the composite with 3 wt% CMFs using PEG as carrier. This enhancement was attributed to the combined effects of fiber reinforcement and cold crystallization induced in the PLA. With NR latex as carrier, the composite of high tensile strength was achieved by introducing the epoxidized rubber (ENR) in a ratio of 2:3 (ENR:NR) as a compatibilizer to improve adhesion between phases in the composites.

The effect of nanocellulose on mechanical and physical properties of chitosan-based biocomposites

“…28 Nanocellulose is a general term that can be divided into two categories based on the size and preparation method, namely cellulose nanofiber (CNF) and cellulose nanocrystal (CNC). 29 CNFs are made of entanglement and long cellulosic chains and retain both their crystalline and amorphous scope. The CNFs have a length of 500-1000 nm.…”

Impact of the Incorporation of Nano-Sized Cellulose Formate on the End Quality of Polylactic Acid Composite Film

“…The good interfacial interaction and good dispersion of nanofillers in the polymer matrix (such as in PLA) are highly needed to achieve the ideal strengthening effect of the composites [ 17 ]. It was reported that some compatibilizers (for instance, polyethylene glycol) could improve the dispersion of fillers in composites [ 18 ], but they are derived from petroleum-based polymers, which are not renewable. On the other hand, partial acetylation of cellulose could be an effective way to enhance the reinforcing effectiveness of NC in PLA matrix [ 19 ].…”

Effect of different cure systems on natural rubber/nanocellulose nanocomposites in rheological, physical-mechanical, aging, and mechanical properties

“…35,38 Mechanical properties before and after aging Nanocomposites from cellulose and NR have been widely studied in several works with different purposes. 47,[50][51][52][53] However, as far as it was possible to search, the articles present their own incorporation technology, different from the one used in this work, which, in general, is simpler experimentally and leads to promising results. Values of mechanical properties as stress resistance, hardness, tear resistance, and compression set for the unfilled composition and the nanocomposites vulcanized with different cure systems are shown in Table 5.…”