Study On The Toughening Of Low Viscosity Epoxy-polyamide Curing System

For it plays good performance in the chemical, physical, mechanical, and electricalinsulation and easy to operate on craft, epoxy resin is widely used in paint industry,machinery industry, electronic industry, transportation industry, automobilemanufacturing, construction, aerospace and other fields, and keep growing demand and agood momentum of development. But as a result of epoxy resin contains a lot of benzenering or heterocyclic structure, small molecular flexibility, toughness of the epoxy resinbefore toughening is poor, and easy to craze. Therefore, the research on tougheningepoxy resin has the significant practical significance.This article based on a new polyamide curing agent, the condensation products ofpolyamine and dimethyl phthalate, instead of in a vegetable oil fatty acid, then discussthe effect and influence when CTBN/ATBN added to toughening of the epoxy-polyamidecuring system, respectively analyzed them from the viscosity, mechanical properties,thermal properties, and compared with their toughening effect:(1) Discussed the dosage of curing agent for epoxy-polyamide curing materiallearning performance, draw the best synthetic formula. When polyamide and CYD-128mass ratio was34%, the mechanics performance index is best, the tensile strengthreached maximum value38.7MPa, reach maximum bending strength105.1MPa, andthe impact strength reached maximum value15.9KJ/m2. Because it is curing fully nearthe optimal proportion.(2) According to the optimal proportion of34%used for curing epoxy resin,polyamide and thermo-gravimetric analysis was carried out on the solidification product.Before300℃, the curing system quality basic unchanged; Began to decompose after300℃,370℃after quality straight decline,50%weight loss temperature is430℃,650℃after quality basically remain unchanged, eventually weightlessness was74%.(3) Discussed the different content of CTBN/ATBN effects on curing viscosity.Viscosity with the increase of CTBN or ATBN content increasing. When CTBN/ATBNadd small amount (less than10%), the system viscosity change less than10%; When CTBN/ATBN addition amount was25%, the viscosity increases rapidly, is three timesmore addition amount was5%. In addition amount equal, due to the viscosity thanCTBN/ATBN itself, ATBN and CTBN and the functional groups they carry the polarityof different size, impact on molecular inter-atomic forces, leading to system viscositydifference.(4) Discussed the different content of CTBN/ATBN effect the performance of thesolidified material to learn. Epoxy-polyamide curing system of the tensile strength andbending strength increased with the increase of CTBN content decreases, and the impactstrength increased with the increase of CTBN content increased. When CTBN content is20%, the toughening of epoxy-polyamide curing system tensile strength as toughening infront of only47.8%, the bending strength for toughening before41.5%, impact strengthfor toughening the top146.5%. Epoxy-polyamide curing system of the tensile strengthincreased with the increase of ATBN content showed a trend of decrease after the firstincreases and the bending strength increased with the increase of ATBN content increases,the impact strength increased with the increase of ATBN content showed a trend ofdecrease after the first increase. When ATBN content is15%, the tensile strength andimpact strength peak, after toughening mechanics properties of epoxy-polyamide curingsystem appear larger changes, the tensile strength as toughening74.4%before, thebending strength for toughening before75.8%, impact strength for toughening before2.59times.(5) Discussed the different content of CTBN/ATBN effects on curing thermalperformance. Discussed the different content of CTBN/ATBN effects on curing thermalperformance. Overall CTBN/ATBN join reduces the thermal properties of epoxy resin,and with the increase of the dosage, the reduction of heat resistance increased. At thesame time, join ATBN thermal performance is better than the CTBN.(6) Compared with the viscosity, mechanical properties and curing thermalperformance of the cured epoxy resin adding15%CTBN and15%ATBN, concluded thatadding15%ATBN to the epoxy resin can obtain good toughening effect.