Development and characterization of novel castor oil-based polyurethane composites containing wood sawdust and rubber tire powder

Abstract

New eco-friendly composites consisting of castor oil-based polyurethane (PU) resin, wood sawdust, and rubber tire powder were produced, and the morphological, physical, and flexural properties were investigated. The composites were composed of varying the concentration of the PU matrix (30, 40, and 50 m%) and the wood-to-rubber ratio of the disperse phase (100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 m%/m% wood/rubber, respectively). The morphology of the composites was studied by optical microscopy and scanning electron microscopy, and the flexural properties, water absorption (WA), and thickness swelling (TS) were also investigated. The analysis of variance was used to study the effect of each factor (PU content and wood/rubber ratio) on the characteristics of the composites. PU/wood/rubber composites were successfully molded and their characteristics are promising for commercial use. According to the results, the composites presenting higher wood content (high wood/rubber ratio) showed higher modulus of rupture and modulus of elasticity values, although the addition and the increase of rubber content decreased these properties. Moreover, increasing PU or reducing the wood/rubber ratio significantly reduced the WA and TS, improving dimensional stability.

Polyurethane‐polyisocyanurate (PUR‐PIR) foams based on castor oil modified with tire rubber waste: Statistical‐based analysis

“…This fact occurred due to the inclusion of a higher content of rubber powder in the PUR matrix because it is a nonpolar material 33 . In addition, rubber creates water resistance due to its hydrophobic character and ability to limit water access to composite 34 …”

“…33 In addition, rubber creates water resistance due to its hydrophobic character and ability to limit water access to composite. 34 In PIR/WTR10% and PIR/WTR20%, there was an increase in the value of the contact angle, obtaining 117.7 and 127.1 , respectively. When comparing polymer results, PIR is less hydrophobic due to the increase in hydroxyl groups, carboxyl groups, and other oxygencontaining polar groups in the isocyanate composition and on the rubber surface of the tire.…”

Optimization of sound-absorbing and insulating structures with 3D printed recycled plastic and tyre rubber using the TOPSIS approach

“…Polyurethane (PU) resin is commonly used as a binder for materials which has to have high mechanical resistance such as asphalts or concrete (Lei et al, 2022; Sun et al, 2022). PU resin is used as a binder for rubber granules in several studies (Semlali Aouragh Hassani et al, 2020; Seibel et al, 2021). Binding techniques with rubber granule often include a hot press around 100°C in the manufacturing process.…”