Four unsaturated polyester resins based on poly(ethyleneglycol-maleatephthalate)
(PE) with different bromine contents were used for the impregnation and
coating of oven-dried white pine wood samples in admixture with styrene (St). Curing
was affected by the initiator–heat technique by using 0.2 wt % of benzoyl peroxide
(Bz2O2). It was found that the use of the four prepared unsaturated polyester/styrene
(PE/St) mixtures resulted in the formation of wood plastic combinations (WPC) with a
higher percentage retention, higher percentage crosslinking, water repellent effectiveness,
and antiswelling efficiency. ASE properties are excellent for wood samples impregnated
with resin without bromine. Water absorption was decreased and a good
water uptake was obtained by wood samples impregnated by resin of lower bromine
content. Compressive strength was increased for all samples, especially for the wood
samples impregnated with resin without bromine. The flammability test for the prepared
plastics showed that the samples without bromine are classified as burning
substance and the other three samples contain bromine are classified as self-extinguishing
samples fromASTMD635-68T (1956). On the other hand, impregnated wood
samples with PE/St mixtures show no fire retardancy after carrying ASTM E160-50
(1965), whereas coated wood samples with the same mixtures show excellent fire retarding properties. |
