Unsaturated polyester resin Toughening

Tasdemir and Yildirim [22] showed that rigid plastics such as epoxies, PS, PVC, polymethyl methacrylate (PMMA), PP, PC, unsaturated polyester resins and PA can be toughened and their impact properties improved by the incorporation in the formulation of 5-20% of a rubbery elastomer such as ABS terpolymer. 

Qunhua Xu, Wei Meng, Xujie Yang et al. Toughened and strengthened unsaturated polyester resin by nanometer titanium dioxide. Polymer Materials Science and Engineering,... 

Maleated polyisobutylene was used as a toughener for unsaturated polyester resins by Abbati et al. [74]. The effect was found to depend on the grafting degree of the rubber and on the time period during which the two-component mixture was allowed to react prior to the curing process. 

Abbati, M., MartusceUi, E., Musto, P., Ragosta, G., and Scarinzi, G., Maleated polyisobutylene A novel toughener for unsaturated polyester resins, J. Appl. Polymer Sci., 58, 1825, 1995. 

Epoxy resins have been toughened by in situ copolymerization of microgels consisting of unsaturated polyesters and bifunctional comonomers [382,383]. 

The toughening effectiveness of impact modifiers of any kind in unsaturated polyester and vinyl ester resins will depend on the rate of impact or applied strain, atmospheric conditions (temperature, presence of solvents), and the toughness of the base resin. As the applied strain rate increases or the lest temperature decreases the effectiveness of the rubber additive may decrease. This is because the rubbery particles and the matrix resin b me more brittle under these conditions. As a result, when comparing toughness data from different sources, testing... 

Ullett, J.S. and Chartoff, R.P. (1995) Toughening of unsaturated polyester and vinyl ester resins with liquid rubbers. Poly. Engr. and Sci., 35,1086-1097. 

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