Preparation And Properties Of EPDM-g-MAH Modified Nylon66

In this paper,EPDM was grafted with maleic anhydride(MAH)to prepare low temperature toughening agent for toughening modification of nylon 66(PA66)and glass fiber(GF)reinforced PA66.For the EPDM-g-MAH system,EPDM-g-MAH toughener was prepared by melt blending with dicumyl peroxide(DCP)as initiator.In this experiment,the effects of the amount of MAH and the amount of DCP on the grafting rate were investigated.Ten toughening agents were prepared and the grafting ratio was calculated by acid-base titration.The tougheners with high,medium and low grafting rates were selected for performance testing.The results show that the T1 toughening agent with the highest grafting rate has the best toughening effect on PA66.The content of MAH in the T1 toughening agent was 2%,the content of DCP was 0.25%,the content of the antioxidant was 0.2%,and the graft ratio was 0.89%.In the toughening PA66 experiment,PA66 was toughened and modified with T1 and Mobil Exxon 1803,respectively,and the mechanical properties were compared.Under normal temperature conditions,the impact strength of pure PA66 is4 kJ/m~2.When the content of toughening agent is 20%,the impact strength of T1 and1803 toughened composites is 78.69 kJ/m~2 and 64.27 kJ/m~2,respectively,which are19.7 times and 16.1 times of pure PA66,respectively.As the content of toughening agent increases,the impact strength of the composite material decreases,and the amount of toughener added is 20%optimal in terms of overall material cost and performance.At the lowest test temperature of-50?,the impact strength is 22.18kJ/m~2,17.41 kJ/m~2,which is 5.5 times and 4.4 times that of pure PA66,respectively.DSC test results show that the glass transition temperature of the composite material modified by self-made T1 is lowered,and the crystallinity is decreased,indicating that the toughening agent T1 has obvious toughening effect on PA66.The TG performance test results show that the composite material has good thermal stability.The SEM test showed that the microstructure of PA66 was obviously improved.The particle size of the dispersed phase of the rubber phase was fine and uniform,and the toughening effect was obvious.In the experiment of strengthening and toughening PA66,the GF-PA66composite system was toughened and modified by T1 and Mobil Exxon 1803,respectively,and the mechanical properties were compared.The tensile strength of GF-PA66 was 187.13 MPa under normal temperature conditions.When the content of T1 and 1803 toughening agent is 2.5%,the strength of the two composite materials has the maximum,and the tensile strength is 188.31 MPa and 191.23 MPa,respectively,and the tensile strength increases slightly.As the content of toughening agent increases,the tensile strength of the composite decreases.In order to ensure the optimum tensile strength of the reinforcing material,the addition amount of the toughening agent is 2.5%.When the minimum test temperature is-50?,the tensile strength of the composite is 197.34 MPa and 196.02 MPa,respectively.DSC test and TG test results show that the toughening agent T1 can make the composites have good low temperature mechanical properties and thermal stability.The SEM test showed that the glass fiber and PA66 showed good adhesion after adding T1toughening agent,and the toughening effect on GF-PA66 system was obvious.