Foaming of PS/wood fiber composites using moisture as a blowing agent

Abstract

This paper presents an experimental study on foam processing of polystyrene (PS) and high‐impact polystyrene HIPS/wood‐fiber composites in extrusion using moisture as a blowing agent. Wood‐fiber inherently contains moisture that can potentially be used as a blowing agent. Undried wood‐fiber was processed together with PS and HIPS materials in extrusion and wood‐fiber composite foams were produced. The cellular morphology and volume expansion ratios of the foamed composites were characterized. Because of the high stiffness of styrenic materials, moisture condensation during cooling after expansion at high temperature did not cause much contraction of the foamed composite and a high volume expansion ratio up to 20 was successfully obtained. The experimental results showed that the expansion ratio could be controlled by varying the processing temperature and the moisture content in the wood fiber. The effects of a small amount of a chemical blowing agent and mineral oil on the cell morphologies of plastic/wood‐fiber composite foams were also investigated.

Effectiveness of Maleated and Acrylic Acid-Functionalized Polyolefin Coupling Agents for HDPE-Wood-Flour Composites

“…URING THE LAST decade, extensive efforts have been made on the use of wood fibers as fillers or reinforcers for thermoplastic matrices [1][2][3][4][5][6][7][8][9][10][11]. The rationale behind these efforts is that wood fibers offer many advantages over the most commonly used inorganic materials including a lower cost on a volumetric basis, higher specific strength and modulus, flexibility during processing, etc.…”

Effects of Alkali Treated Nano-kenaf Fiber in Polypropylene Composite upon Mechanical Property Changes

“…45,46 It has been confirmed by studies that volatile extractives are present in natural fiber 40,47,48 and they are responsible for decrease of mechanical property of the compound. 27,42,45,47,49 Yosomiya argued that poor adhesion of a material is due to presence of low surface tension material such as impurities or adsorbed water layers. 50 This leads to interfacial de-wetting between fiber surface and polymer matrix.…”

Feasibility of Using Foamed Styrene Maleic Anhydride (SMA) Co-polymer in Wood Based Composites

“…After all, natural fi ber-fi lled polymer composites commonly have high densities. Therefore, the composites can be foamed to lessen their density using chemical or physical blowing agents (Rizvi et al, 2000). Natural fi ller reinforced composites have shown excellent performance regarding physical, mechanical and thermal properties (Ozen et al, 2013; Kiziltas et al, 2014).…”

“…Polystyrene/wood foamed composites were studied by Rizvi et al, (2000), who used hydrocerol compounds and wood particle water (moisture content of 8 %) at 130 °C and 140 °C. These results have shown that expansion ratio was 9 to 20 %.…”

“…On the other hand, common aliphatic hydrocarbons are highly fl ammable. The blowing agents have a high price and low gas concentration during their decomposition (Rizvi et al, 2000). The government continues to promulgate regulations aimed at enhancing environmental protection and worker safety.…”