Unsaturated polyester resins modified with vegetable oil and dicyclopentadiene

摘要

The effects of the amounts of vegetable oil and dicyclopentadie-ne,incorporated into the structure of unsaturated polyesters,on the physical and chemical characteristics of uncured resins(Table 2)as well as on functional properties of cured products(Table 3,Figs.4-7)were investigated.Rape oil in the amount up to 20 wt.% and DCPD in the amount equal 10 wt.% were used.Unsaturated polyester resins(UP)based on maleic or phthalic anhydrides and ethylene or 1,2-propylene glycols.The roles of an oil and DCPD in polycondensation reaction have been explained on the basis of ~1H NMR spectra(Figs.1-3).An increase in vegetable oil content causes increase in tensile strength,flexural strength,unit elongation at break and impact strength of cured polyester resin(i.e.properties dependent on flexibilization degree).However hardness,compression strength and heat deflection temperature(HDT)slightly decrease.Incorporation of DCPD molecules into unsaturated polyester chain causes an improvement in flexural strength,compression strength and hardness and also increase in HDT value.DCPD presence improves also chemical resistance of a resin,particularly resistance to water and alkaline media(Table 4).