Wood‐based composites with thermoplastic polyurethane as matrix polymer

Abstract

This research reports the influence of the mechanical properties of thermoplastic polyurethane (TPU) as a function of wood filler percentage. Wood flour was mixed with two different chemically based TPUs. Also, moisture content during compounding process as well as the origin of moisture (wood or TPU) were studied. All experimental designs and statistical analysis were done with the software Design Expert Version 10. Composite preparation took place in a multi‐stage process. The results showed that 70% wood filler can be incorporated in the composite manufacture. The properties of the composite were mainly influenced by the proportion of wood and TPU. Wood flour increased the density, hardness, water absorption, and tensile modulus with a decrease in impact resistance and abrasion resistance of the composite. Tensile strength exhibited a decrease up to ∼35% wood content, but an increase with further addition of wood. Moisture content had only a minor influence on the mechanical and water absorption properties despite the noted severe moisture sensitivity of TPU, which usually leads to decline in mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46344.

Preparation of thermoplastic polyurethane-based biocomposites through injection molding: Effect of the filler type and content

“…The MCC-, RH-, and TK-filled TPU composites provided similar TM values, and they were higher than unfilled TPU specimens. In TPU-based composites, a similar increase corresponding to filler content was also reported by Diestel and Krause (2018). The TM values of composites with a low-stiffness matrix and high-stiffness filler increases with a rising percentage of filler (El-Shekeil et al 2012).…”

“…TS values of RH-and TK-filled composites at 30% filler loading level were reduced. It has been reported that the rate of lignocellulosic filler had an effect on the TS values of TPU composites (El-Shekeil et al 2012;Diestel and Krause 2018). El-Shekeil et al (2012) reported that TS values increased up to 30% filler content in their studies that examined 20, 30, 40, and 50% lignocellulosic filler in TPU composites.…”

“…El-Shekeil et al (2012) reported that TS values increased up to 30% filler content in their studies that examined 20, 30, 40, and 50% lignocellulosic filler in TPU composites. Conversely, Diestel and Krause (2018) reported that TS decreased when greater than 30% lignocellulosic filler was used. It should be mentioned that in a second study, a complex experimental design was tested, wherein low (30%) and high (70%) filler loading levels were used and different factor interactions were investigated.…”

“…When filler with higher density is incorporated into a polymer matrix with lower density, the resulting composite usually has a higher density than that of the polymer itself. This increase is believed to be due to the higher cell wall density of lignocellulosic materials (approximately 1.5 g/cm 3 ) (Matuana et al 1998;Mäkinen et al 2002;Clemons 2010;Diestel and Krause 2018;Çavuş 2020).…”

“…Increased fiber loading also resulted in a decline in impact strength and abrasion resistance. Diestel and Krause (2018) conducted a study on wood fiber (Arbocel® C100)-filled TPU composites, investigating the effect of filler loading levels on mechanical properties. They also studied the effect of moisture and the type of TPU (polyester or polyether) on those properties.…”