Phenolic Foams Modified Research

Phenolic insulation board is phenolic resin and curing agent,foaming agent,surfactant mixed preparation of pass a kind of heat preservation,fireproofing and heat resistance of foam board.Phenolic foam board of flame retardant,low smoke,high temperature resistant efficient organic foam material,and application in building energy conservation industry development has a great prospect.Phenolic insulation board in organic products,has been as one of the fastest-growing products,good stability,low temperature resistant,flame retardant,self-extinguishing,smoke,and meet flame without penetration,encounter flame melt dripping and other special performance is their advantages,therefore,the development of phenolic foam insulation system in the building,use scope gradually development,discussion and analysis are quite active at home and abroad.Phenolic foam through in recent years,however,exterior insulation application proves that the phenolic insulation board still exist certain brittleness,high acid deficiencies.Then lower coefficient of thermal conductivity and reduce acidity and enhance its toughness effect,is the premise of perfecting phenolic insulation board physical indicators.In the future to develop the high efficiency and energy saving,green,environmental protection heat preservation material,is also the requirement of the national economy development,keep up with the trend of the historical development.Phenolic insulation look is in line with the construction of economical society and the requirement of the sustainable development strategy,will be booming.Because phenolic insulation board also has a lot of the shortcomings,such as resin in phenolic hydroxyl and methylene produce oxidation reaction,particularly easily causes phenolic insulation board compression strength drop,easy pulverization,large brittleness,and many other defects,phenolic foam plastic in practical use has been limited,above all shows that the modified phenolic insulation board to investigate and analysis is necessary.This article mainly from the following several direction of phenolic insulation board is studied,by changing the synthesis process recipe,achieve a low free formaldehyde content and physical properties of the modified phenolic insulation board.First,this paper discusses low free formaldehyde ratio of phenolic resin.The different varieties and different usage of the catalysts,the use amount of phenol and the molar ratio of consumption of paraformaldehyde(F/P),synthetic duration and temperature of the index of the test,the results found that should be taken to NAOH as catalyst,the dosage of 3%,F/P was 1.6,test temperature at 90?,can get bonus time for 3 h phenolic resin of low free formaldehyde.Second,the phenolic resin toughening methods was discussed.Toughening agent is added in the event of a synthetic effect,is polyethylene glycol,acrylic,polyvinyl alcohol and MDI polyurethane prepolymer with polyethylene glycol blending modification effect,test to prove:MDI polyurethane prepolymer with polyethylene glycol blending effect is best.modifier were added in the synthesis process respectively to study the phenolic resin toughening method.The experimental results show that the toughening effect of MDI polyurethane prepolymer modified phenolic resin is the best.Third,the optimization of synthesis process.In the process of resin foaming effect,increasing curing agent usage,making phenolic insulation board density and compressive capacity after the first small to big,and water absorption to follow increase.Excessive if when curing agent USES harden signs,bibulous rate is reduced,thus the solidification time of the phenolic insulation board and shortened.When the increase dosage of foaming agent,can make the phenolic insulation board density decreases and compressive ability is abate,will prolong the time of solidification.Phenolic insulation board when increasing the dosage of active agent,bibulous rate is lower,extend the time of solidification,density and compressive capacity increased.Ratio of the comprehensive consideration,the optimal foam insulation board as follows:curing agent 16%,foaming agent6%,surfactant5%.Fourth,through the above research preparation phenolic plate made of physical indicators have improved.Bulk density was reduced by 14%;Coefficient of thermal conducti-vity(average temperature 25?)by 27%;The compression strength increase 61%;Water absorption by 17%;The bending fracture increased by 40%.