Thermal properties of tropical wood–polymer composites

Abstract

SYNOPSISWood-polymer composites ( WPC) of Geronggang ( GE; Crutoxylon arborescens) , a light tropical hardwood, impregnated with methyl methacrylate (MMA ) , styrene-co-acrylonitrile ( 3 : 2; STAN), methyl methacrylate-co-bis( 2-chloroethy1)vinyl phosphonate ( 3 : 1; MVP) and methyl methacrylate-co-bis (chloropropyl) -2-propene phosphonate ( 3 : 1; MPP) , were prepared by in situ polymerization using y-radiation or catalyst-heat treatment. Thermal characterization of these WPC by limiting oxygen index measurements (LOI) , thermogravimetry (TG) , and differential scanning calorimetry (DSC) showed that the impregnants greatly modified the wood properties. The LO1 values of the GE-MVP and GE-MPP composites were much higher than that for GE and the other composites, indicating the effectiveness of the phosphonates as flame retardants. Concomitantly, the flaming characteristics also compared favorably against that for GE and the other composites. The decomposition temperature and maximum rate of weight loss determined by TG for GE-MVP and GE-MPP were substantially reduced, whereas the char yields were greatly higher. These observations again indicate that phosphonates imparted flame-retarding properties to their composites. The thermal properties of GE-MMA and GE-STAN composites were not vastly different from that of untreated GE. Flame retardancy in the phosphonatecontaining composites was effected through both the condensed-and gaseous-phase mechanisms due to the presence of phosphorus and chlorine, respectively. Indication of grafting of polymer to wood was found for GE-STAN, GE-MVP, and GE-MPP composites, but not for GE-MMA. Composites prepared by y-radiation or by the catalyst-heat treatment had similar thermal characteristics.

Thermogravimetric behavior of natural fibers reinforced polymer composites—An overview

“…Works referred in that section [22][23][24][25][26][27][28][29] served for the brief summary on the state of art discussed by these authors [2]. In two conference articles on thermal analysis of lignocellulosic materials, Nguyen et al [22,23] reviewed the effect of temperature on cellulose, hemicellulose, lignin, and other carbohydrates as well as different types of wood.…”

Development of new composites materials, carriers of active agents, from biodegradable polymers and wood

“…The first one consists in impregnating porous wood samples with the active agent [11][12][13][14], followed by the impregnation of e-caprolactone, which is polymerised inside the wood. PCL is supposed to fill the micro-channels of porous wood.…”

Environment Friendly Composite Materials: Biocomposites and Green Composites

“…Sabaa 81 has also reported improved thermal stability for acrylonitrile-grafted sisal fibers as evidenced by the increased initial degradation temperature, lowering of the rate of degradation and the total weight loss. In another study 82 , the polymer wood composites were prepared by in situ polymerization of various monomers and it was observed that the maximum rate of degradation was substantially reduced for phosphonate-treated wood flour. Natural fibers (lingo-cellulosics) are degraded by biological organisms since they can recognize carbohydrate polymers in the cell wall.…”