Toughening Modification Of Phenolic Resin

Phenolic resins have been widely used in many fields due to their excellent flameresistance, insulativity, adhesivity and chemical resistance. But phenolic resin withoutmodifying was limited application in some areas because of brittleness. In order toimprove the performance of phenolic resins and further expand their scope ofapplication they should be modified to improve toughness and heat resistance. Thisthesis studied phenolic resins separately modified by hydroxyl-terminated polybutadiene, polyvinyl alcohol and polyurethane. The objective is mainly to improve thetoughness and studies the way of different toughening effect on the resin performance.(1)At first commercial phenolic resin was modified by different models andmasses of hydroxyl-terminated liquid polybutadiene (HTPB). The viscosity, solubilityof water, impact strength, impacted cross section morphology and TG of the modifiedphenolic resin were measured. The test results showed that the viscosity increased to6000mPa.S, solubility of water decreased to0.7and sizability declined. The impactstrength reached3.6KJ/m2when entered HTPB (H0711-06) which possessed3%of themass fraction of the phenolic resin. The modified phenolic resin in450℃appeared amodifier decomposition peak. TG analysis showed that heat resistance of modifiedphenolic decreased. The results showed that modification effect of HTPB with thebiggest hydroxyl value was best, taking the HTPB (H0711-06) as the modifier, in thedifferent process and different weight of phenolic resin composition adding modifierrespectively, and the modification effect of modified phenolic resin was tested. Resultsshowed that: added the HTPB to system which possessed5%of the mass fraction ofthe phenolic resin before the synthesis reaction of phenolic resin. The modifiedphenolic resin viscosity was1000mPa. S, solubility of water1.4, mpact strength5KJ/m2and sizability was good. The modification effect was best, heat resistanceremain unchanged basically.(2)The commercial phenolic resin was modified by polyvinyl akohol solution of10%. Research showed that the solubility of water decreased integrally, viscositydecreased firstly then increased gradually. When after adding polyvinyl alcohol1788which possessed3%of the mass fraction of the phenolic resin impact strength was3.8 KJ/m2, but heat resistance decreased.(3)The hydroxyl-terminated polyurethane with water soluble and differentmolecular weight was synthesized. With it toughened phenolic resin. The studyshowed that with the increase of the dosage of modifier, the viscosity of modifiedphenolic resin increased to1600mPa.S slowly, solubility of water decreased to0.1gradually. When adding polyurethane which possessed1%of the mass fraction of thephenolic resin, phenolic resin impact strength reached5KJ/m2. The modified phenolicresin in400℃appeared a modifier decomposition peak and heat resistance decreased.