Reuse of waste paper and rice hulls as filler in polymeric matrix composites

Abstract

Concerns for the environment are recurrent in our society, and research on low impact materials such as those produced from waste is an alternative. This work is based on the reuse of scrap paper and rice hulls aiming to increase the life cycle of these waste products and to find better destination. Composites with a volumetric filler content (dispersed phase) of 80% were produced via compression molding using polyurethane (PU) based on castor oil or polyester resin as matrix, in four distinct families: polyester/rice hulls, PU/rice hulls, polyester/paper and PU/paper. The following tests were performed: water sorption, contact angle, hardness, impact and tensile testing. Scanning electron microscopy (SEM) was used for fracture morphology study. Basic visual analysis showed greater void content for the rice hull composites, making them less aesthetically appealing compared to paper. It was observed in the case of PU matrix the filler greatly influenced the rigidity since this pure material was more flexible compared to pure polyester. Filler incorporation decreased tensile strength of the polyester matrix but significantly increased that of the PU matrix.

Waste Paper as a Valuable Resource: An Overview of Recent Trends in the Polymeric Composites Field

“…PU/WP composites have only been reported recently. The first work reported PU and polyester mixed with WP and rice hulls, considering 80 v / v % of filler from which the composite plates were produced by compression molding [ 96 ]. The results showed that PU/WP presented the best water resistance performance.…”

Production and mechanical characterization of polyethylene matrix composites with the addition of linen and cotton waste fabric filler materials

“…Other researchers concluded that ramie addition positively affected the mechanical properties of polyester matrix composites whereas effect of cotton fibers remained limited [20]. The results found in literature clearly show that the mechanical properties are a result of the combination of the type, content and state of prior chemical treatment of the reinforcement fibers and the type of the polymer matrix used to produce the composites [15,21].…”

“…In addition to this, the difference in the interaction of the filler fibers with the matrix polymer also affects the tensile strengths of the samples. Calegari et al [21] stated that tensile strength of the samples changed with the matrix polymer material where the same filler materials cause different effects on the tensile strength values in the same polymer matrix.…”

Exploring new horizons for paper recycling: A review of biomaterials and biorefinery feedstocks derived from wastepaper

“…Fibers are commonly used as reinforcing materials in composite applications because of their high aspect ratios which provide high tensile strength and other material properties. Wastepaper (WP) was used as a filler in samples of polyester (P) and polyurethane (PU) as a matrix, with matrix to filler ratio of 20:80 [12]. The tensile strength for the P/WP composite reduced from 17.8±0.5 MPa to…”