Density reduction behaviors and cell morphology in extrusion of LLDPE/wood fiber composites with physical and chemical blowing agents

Abstract

Foamed wood fiber/plastic composites (WPC) with a fine‐cell structure offer many benefits compared with the unfoamed WPC, such as the reduced material cost and density, the improved toughness, and the enhanced processability. However, it is extremely challenging to achieve the desired density reduction and obtain a fine‐cell structure simultaneously. One of the obstacles is that the volatiles released from the wood fiber (WF) during processing should be suppressed to ensure a fine‐cell structure. Linear low‐density polyethylene (LLDPE) has a relatively low melting temperature, and it can reduce the processing temperature and suppress volatiles when used as a polymer matrix for foamed WPC. This paper systematically investigates the foamability of LLDPE/WF composites in a continuous foam extrusion, with both a chemical blowing agent and a physical blowing agent (PBA). It turns out that the PBA‐based foaming led to a smaller cell size and a narrower cell size distribution. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48829.

Fabrication of LLDPE based biodegradable composite incorporated with leather shavings and buffing dust: An approach for waste management

“…20,21 LLDPE/wood fiber composite blown film was prepared to fabricate density reduction behavior and fine cell composites. 22 Lignin-based composite films with LLDPE were fabricated, resulting in improved mechanical strength, thermal stability, and environmental safety. 23 In a recent study, gas barrier property was improved by fabricating cellulose nanocrystals/LLDPE composites.…”

“…LLDPE based active nanocomposite films with nanoclays impregnated with volatile compounds were fabricated for antimicrobial food packaging 20,21 . LLDPE/wood fiber composite blown film was prepared to fabricate density reduction behavior and fine cell composites 22 . Lignin‐based composite films with LLDPE were fabricated, resulting in improved mechanical strength, thermal stability, and environmental safety 23 .…”

Mechanical characteristics and hydrophobicity of alkyl ketene dimer compatibilized hybrid biopolymer composites

“…Similar results were also reported in the literature. [53] Figures 1 and 2 show the water absorption and the thickness swelling of the hybrid PLA composites after immersion in distilled water for 30 days, 60 days, and 90 days at room temperature, respectively. The results of water uptake tests show that the water absorption and thickness swelling of the hybrid PLA composites increased with increase in amount of NF into polymer matrix (Figure 1).…”

Tensile and longitudinal shrinkage behaviors of polylactide/wood‐fiber composites via direct injection molding

“…Natural fibers, such as flax fiber, [2,3] kenaf fiber, [4] coir fiber, [5] and bamboo fiber, [6,7] have been used as a reinforcing or cost reducing filler to make sustainable eco-friendly PLA biocomposites. Wood fiber (WF), a type of natural fiber, has been widely used to make wood-plastic composites (WPC) [8][9][10][11][12][13][14][15][16][17][18] or hybrid composites, [19][20][21] because WF offers advantages such as low cost, low density and less wear to processing equipment. In the recent years, WF has been incorporated in PLA matrix to make "fully green" PLA/WF composites, because they are completely biodegradable and renewable.…”