Preparation Of SEBS-g-MAH And Adhesion Performance In TPE Coated Nylon

Currently,coated products made with rigid plastics（such as polypropylene,nylon,etc.）as the base material and thermoplastic elastomers as the cladding material,have both the mechanical properties of rigid materials and the good touch of TPE,and are widely used in sports equipment,household goods,automotive technology,and other fields.Styrene ethylene butene styrene block copolymer（SEBS）is a thermoplastic elastomer,which has a wide range of applications due to its good rubber elasticity,excellent weather resistance,stability,and so on.However,SEBS molecules themselves do not have polarity,and when coated with polar materials,there is often a problem of poor adhesion between the two materials.In addition,SEBS materials have a high melt viscosity,which is difficult to process and expensive,and the cost of industrial production is high.Therefore,they are often modified to improve their comprehensive performance.Based on the above issues,this article,on the basis of using polypropylene,paraffin oil,and inorganic fillers to modify SEBS materials,self-made modifier SEBS-g-MAH,introduced maleic anhydride polar groups into TPE to improve the adhesive properties of the materials,characterized the properties of the composite system,and discussed the impact of the addition of SEBS-g-MAH on the composite system.The specific work is as follows:The self-made modifier SEBS-g-MAH was characterized by Fourier transform infrared spectroscopy（FTIR）.The grafting rate of the self-made modifier was calculated by acid-base titration.The effects of maleic anhydride（MAH）and initiator（DCP）on the grafting rate and properties were studied by melt flow rate testing.The results showed that there was a characteristic absorption peak of maleic anhydride at1785 cm^-1 in the FTIR diagram,indicating that the MAH group was successfully grafted onto the molecular chain of SEBS,When SEBS/MAH/DCP=100/2/0.2,the grafting ratio of SEBS g-MAH is 1.57%,and the melt index is 2.43g/10min.At this time,the grafting ratio is higher,and the fluidity is better.Using polypropylene（PP）as a modified resin,paraffin oil as a filling oil,and talc powder as a filler,SEBS was modified.The mechanical and flow properties of the material were characterized.The results showed that when the distribution ratio of each component was SEBS/PP/paraffin oil/talc powder=30/20/30/20,the Shore A hardness of SEBS based TPE was 75,the tensile strength was 12.4MPa,the elongation at break was 880%,and the melt index was 16.8g/10min,The mechanical and processing properties of SEBS/PP have been significantly improved.Modified TPE was prepared by adding modifier SEBS-g-MAH based on the above experimental ratio.The effects of grafting ratio and dosage of SEBS-g-MAH on the mechanical properties and flow properties of modified TPE were studied;Using glass fiber reinforced PA6 as the base material and modified TPE as the coating material,the adhesive coated nylon was prepared by secondary molding,and its adhesive properties were tested.The results showed that the addition of SEBS g-MAH slightly improved the mechanical and flow properties of SEBS based TPE.From the peeling strength and SEM of the material,it can be seen that the adhesive properties of modified TPE were significantly improved.When the grafting ratio of SEBS-g-MAH is 1.57%and a 6phr modifier is added,the peel strength can reach 5.2k N/m,at this time,the comprehensive performance is the best.