Investigation Of Thermo-oxidative Aging Ability For ABS Resin

In the molding process,the acrylonitrile-butadiene-styrene terpolymer(ABS resin)is easily retained in the barrel aging,making the product appearance yellowing,mechanics and strength of resins changing.Antioxidants can usually improve the resin thermo-oxidation ageing resistance during its processing.The prupose of this study was to synthesize antioxidant GM by esterification reaction and compared with other commercially available antioxidants.Different antioxidant ABS resin pellets were synthesized by mixing with ABS powder with addition of 3 phr of antioxidant GM,antioxidant 618,antioxidant 1076,and antioxidant 3114 respectively.Control group is blank samples without antioxidants.The effect of antioxidants on thermo-oxidative aging properties in ABS materials were tested by infrared spectrum,differential scanning,and thermogravimetric analysis.First,the ABS resin sample's color difference under designed injection molding environment was tested.Under certain injection molding conditions,the color difference of the ABS sample with antioxidant GM decreased from 2.30 to 1.01.In the temperature range from 250 to 350?,ABS samples increased the initial weight loss temperature(T1%)from 273.9 ? to 308.0 ? due to GM's structurally unique acrylate groups and rapidly intramolecular hydrogen bonds transference.Antioxidant 618 can effectively decrease the yellow index of samples from 21.72 to 20.91 and increase the impact strength from 21.06 k J/m2 to 23.46 k J/m2 under 180-210?,because of its phosphate structure.Second,performance of antioxidants added different samples under long-term and high-temperature environment was tested.After 8 cycles of thermo-oxidative aging process,the carbonyl index sample with GM reduced from 2.50 to 0.68,and the color difference reduced from 9.00 to 7.60,which was significantly higher than other samples,indicating that antioxidant GM performed better in reducing the sample's color change caused by thermo-oxidative aging process.The yellow index of the ABS sample with antioxidant 618 decreased from 41.13 to 39.15 after 8 aging cycles.In addition,the tensile strength of the sample added antioxidant 3114 increased from 46.40 MPa to 48.90 MPa,and the melt index increased from 20.08 g·(10min)-1 to 22.96 g·(10min)-1.Third,properties change in ABS pellets added different antioxidants was tested by repeating extrusion.The initial decomposition temperature of the ABS sample added with antioxidant GM increased from 381.3 ? to 411.8 ?,and the yellow index decreased from 35.23 to 32.16 after 5 times repeated extrusion,showing excellent thermo-oxidative stability and color retention.Samples with antioxidant 618 increased the oxidation-induced temperature from 192.9 ? to 217.4 ?;the melt index of ABS samples added with antioxidant 3114 increased from 21.76 g·(10min)-1to 21.95 g·(10min)-1,giving the ABS resin matrix good molecular mobility.