Study On Synthesis And Structural Properties Relations Of Styrene-based Thermoplastic Elastomers Based On Myrcene

As a bio-based chain-like monoterpene,myrcene has a chemical structure similar to that of isoprene and butadiene.It can be introduced into styrenic thermoplastic elastomer through anionic polymerization to develop functional elasticity.And it can further improve the application value of myrcene.In addition,the research on polymers containing myrcene with long side chain structure can further improve the relationship between the microstructure and macroscopic properties of elastomer materials,and has important theoretical significance and application value.The main research contents and conclusions of this article are as follows:First,design and synthesize styrene-isoprene/myrcene-styrene thermoplastic elastomer(SIMS)with different myrcene content without conditioner.The results showed that the content of myrcene increased from 0 to 19.8%,the structure of 3,4-PM decreased from 7.5%to 5.6%,and the structure of 3,4-PI was about 10%;DSC results showed that the glass transition temperature of SIMS was stable at-66?;with the increase of myrcene,the SIMS loss factor will increase first and then decrease.When the content of myrcene is 11.3%,it will reach a maximum value of 1.15;the tensile strength of SIMS will increase first and then decrease,and its elongation at break The elongation rate gradually increases,and the Shore hardness decreases gradually.HSIMS was obtained by using nickel-based catalytic hydrogenation for SIMS.The results show that under the same catalytic conditions,with the increase of myrcene content,the hydrogenation degree of HSIMS gradually decreases,but the overall hydrogenation degree is above 96.7%;the microstructure change law is consistent with SIMS;the glass transition temperature of HSIMS gradually Increased,and are higher than the glass transition temperature of unhydrogenated.With the increase of myrcene content,the peak of the loss factor of HSIMS will increase first and then decrease.When the content of myrcene is 7.6%,the peak of the loss factor reaches the maximum value of 1.45;with the increase of the content of myrcene,the pull of HSIMS The tensile strength gradually decreases,the elongation at break gradually increases,and the Shore hardness gradually decreases.A styrene-myrcene/butadiene-styrene thermoplastic elastomer(SBMS)was designed and synthesized and the relationship between its microstructure and properties was studied.The results show that the content of 1,2-PB structure in SBMS first decreases from 11.2%to 9%with the increase of myrcene content,and then basically stabilizes;the content of myrcene increases from 0 to 70%,and the glass transition temperature of SBMS from-97.3? increased to-67.4?.The addition of a small amount of myrcene greatly increased the elongation at break of SBMS,but as the content of myrcene further increased,the tensile strength of SBMS first increased and then decreased,the elongation at break gradually decreased,and the Shore hardness also gradually decreased.HSBMS was prepared by hydrogenating SBMS using a nickel-based catalytic system.The results of the study showed that the content of myrcene increased from 9.1%to 39.3%,the overall hydrogenation degree of HSBMS was above 94.5%,of which the hydrogenation degree of butadiene was above 97%,and the hydrogenation degree of myrcene decreased from 98.3%83.4%.After hydrogenation,the glass transition temperature increased from-66.6? to-36.6?.With the increase of myrcene content,the peak loss factor of HSBMS does not change significantly,the tensile strength gradually decreases,the elongation at break does not increase significantly,and the Shore hardness does not change significantly.Finally,a partial hydrogenation product PHSBMS was prepared by hydrogenating SBMS using a titanocene catalytic system.The results showed that the myrcene content increased from 10%to 52.2%,the total hydrogenation degree was reduced from 93.7%to 68%,of which the butadiene hydrogenation degree was maintained at about 95%,and the myrcene hydrogenation degree was reduced from 84.3%11.6%.After hydrogenation,the glass transition temperature increased from-70.5? to-40.2?.With the increase of myrcene content,the peak value of PHBMS loss factor gradually increases,the tensile strength gradually decreases,the elongation at break gradually increases,and the Shore hardness gradually decreases.