WOOD PLASTIC COMPOSITE USING DIFFERENT MONOMERS IN PRESENCE OF ADDITIVES

Wood plastic composites (WPC) are prepared with low density wood simul under Co-60 gamma radiation using acrylamide (AM), butyl methacrylate (BMA), and styrene (ST) as the bulk monomers at different, compositions with methanol used as swelling agent. The effect of additives, e.g., polyfunctional monomers and oligomers, used by 1% v/v or w/v, on the polymer loading and tensile strength of the composites is investigated. Polyfunctional monomers are N-vinyl pyrrolidone (NVP), tripropylene gylcol diacrylate (TPGDA), and trimethylol propane triacrylate (TMPTA). Oligomer additives are urethane acrylate (UA), epoxy acrylate (EA), and polyester acrylate (PEA). Increased polymer loading (PL) with enhanced tensile strength (TS) are obtained with the composite. Incorporation of a small amount (1% v/v or w/v) of coadditives like sulfuric acid (H+), lithium nitrate (Li+), copper sulfate (Cu2+), and urea (U) into the impregnating solutions containing the additives has significantly influenced the PL and TS values of the WPC. Though the H+ ion has synergistically enhanced the PL, but it has drastically reduced the TS values. Li+ ion has played a good role for the replacement of H+ ion. Urea has substantially increased the PL values with relatively small enhancement of TS. Cu2+ ions have retained both PL and TS values of the WPC, which could be used as protective and preservative purposes of the composites. (C) 1993 John Wiley & Sons, Inc.