Preparation Technology Of Polymer Waterborne Antioxidant And Thermal Oxidative Aging Mechanism In ABS Resin

ABS resin is a two-phase terpolymer.The presence of unsaturated rubber increases the thermal and oxygen instability of the material,which limits the application of ABS resin.Thus,it is important to improve the thermal and oxygen stabilization of ABS resin.To improve the antioxidant performance,the waterborne antioxidant emulsion was introduced into ABS graft copolymers.In this paper,the effects of the emulsification method and emulsification process on the performance of aqueous antioxidant emulsions and the relationship between the antioxidant efficacy and the concentration of effective functional groups of multiply compounded aqueous antioxidant emulsions were studied.The results of infrared spectroscopy(ATR-FTIR)show the chemical structure changes of ABS graft copolymers during the degradation process.1.The performance of the waterborne antioxidant emulsion prepared by the low-energy phase inversion method is much better than that of the direct emulsification method.Nanoscale aqueous antioxidant emulsions with particle size less than 200 nm,viscosity less than100 cps,and instability index less than 1 can be obtained through the adjustment of process parameters such as Hydrophilic-Lipophilic Balance(HLB)value,temperature,and dosage of emulsifiers;2.The relationship between the performance parameters of aqueous antioxidant emulsions and their antioxidant efficacy was investigated.The waterborne antioxidant emulsions were added to ABS graft copolymers for oxidation experiments.The effects of emulsifier type,particle size,and mixed antioxidants on the antioxidant efficacy of waterborne antioxidant emulsions were investigated.The results showed that the waterborne antioxidant emulsions with suitable emulsifier type,small particle size,good emulsion stability,and high concentration of effective functional groups could achieve the maximum antioxidant efficacy in the ABS graft copolymer,which oxidation induction time(OIT)was up to 96.6 min;3.It is proposed that the effective functional group ratio concentration is used to screen the multiple mixed antioxidants.Both activation energy and oxidation induction time can be used to characterize the thermal oxygen stability of ABS graft copolymer.In general,the effective functional group concentration of the compounded antioxidants was directly proportional to their antioxidant capacity;but it was also influenced by the molecular weight and intermolecular forces of the antioxidant molecules.Experimental results show that the higher the activation energy of ABS graft copolymer,the longer its oxidation induction time,the greater the energy barrier for the oxidative degradation reaction to occur,and the stronger the stabilization of the sample;4.The results of ATR-FTIR show that the degradation of ABS graft copolymers starts with the reduction of double bonds in polybutadiene,which is followed by the breakage of molecular chains,cross-linking,volatilization of low molecular weight substances,and the final charred residue containing the cross-linked structure of carbonyl groups.