Study On Modification Of PA6/PPOalloy

Polyphenylene oxide（PPO）and polyamide six（PA6）are two engineering materials widely used.But pure PPO and PA6 have their own defects that can not be ignored,which greatly limits their application in some fields.PA6/PPO alloy is the second generation of polyphenylene oxide alloy introduced after PPO/PS,excellent PA6/PPO alloy can achieve the purpose of complementary advantages.So that the alloy has the advantages of high toughness,excellent heat resistance,solvent resistance and easy processing and molding,which can greatly expand its application field.The main research work of this paper includes: self-made compatibilizer PPO-g-MAH.PPO-g-MAH with different grafting rates was prepared by changing the addition amount of maleic anhydride（MAH）and initiator（DCP）.The properties of compatibilizers with different grafting rates were analyzed by fourier transform infrared spectroscopy and other properties.The results showed that a clear anhydride absorption peak can be seen at 1713 cm-1 and 1751cm-1 in the FTIR diagram,indicating that MAH group has been successfully grafted onto polyphenylene ether.Under the experimental conditions.When MAH content was about 1.6% and DPC was 0.05%,the grafting rate of PPO-g-MAH is 1.21% and the melt index is 15.1 g/10 min.At this time,the grafting rate of compatibilizer is high and the fluidity is good.PA6,PPO,PPO-g-MAH with different grafting ratios and other additives were put into a twin-screw extruder according to a fixed ratio to prepare compatibilized PA6/PPO alloy.The effect of different grafting rate of Compatibilizer on the compatibilization effect of the alloy was investigated,and PPO-g-MAH with appropriate grafting rate was determined to be used to compatibilize and modify PA6/PPO alloy.The results showed that in this experiment,PPO-g-MAH with grafting rate of 1.21% has the best compatibilization effect on the alloy.At this time,the dispersed phase of the alloy is evenly distributed,the particle size is significantly reduced,the two-phase adhesion is enhanced,and the interface is fuzzy.Compatibilizer can not directly affect the toughness of the alloy,but the notch impact strength of the alloy increases due to the increase of two-phase adhesion.When PPO-g-MAH with grafting rate of 1.21% is added as compatibilizer,the impact strength of the alloy is 8.3 KJ/m2.On the basis of adding a fixed number of PPO-g-MAH,different kinds and ratios of toughening agents POE-g-MAH and SEBS-g-MAH were added again.PA6/PPO alloy with high toughness and high strength was prepared by means of mechanical property test,melt index measurement,DSC analysis and SEM photo observation.The results showed that the addition of toughening agent will reduce the crystallinity and heat resistance of PA6/PPO alloy.When POE-g-MAH is added separately as toughening agent and 5 parts are added,the alloy has the best properties,with notch impact strength of 26.9 k J/m2,tensile strength of 65 MPa and bending strength of 83 MPa.When SEBS-g-MAH is added separately as toughening agent and 3 parts are added,the alloy has the best performance.At this time,the notch impact strength of the alloy is 30.79 k J/m2,the tensile strength is 65 MPa and the bending strength is 80 MPa.When POE-g-MAH and SEBS-g-MAH are added in combination,and the addition ratio is 3 parts of POE-g-MAH + 5 parts of SEBS-g-MAH,the alloy has better properties.At this time,the notch impact strength of the alloy is 25.2 KJ/m2,the tensile strength is 64 MPa,the bending strength is 79 MPa,and the melt index is6.2 g/10 min.SEM photos show that the addition of toughening agent can effectively increase the two-phase adhesion,further reduce the particle size of dispersed phase and disperse evenly.At the same time,POE-g-MAH will form small particle size aggregates,which can absorb a lot of energy when the alloy is subjected to impact stress.Some SEBS-g-MAH will form a "core-shell structure" with POE in the alloy to absorb stress impact,so as to improve the toughness of the alloy.