Research On Radical Reactivity Of SEBS Containing C-C Weak Bond And Conduct Polarity Modification Of SEBS

Styrene-ethylene-butylene-styrene block copolymer named SEBS is the hydrogenated product of styrene-butadiene-styrene (SBS), which is one of the most important products of styrenic thermoplastic elastomer (TPS). SEBS has good mechanical properties, excellent thermal solution capabilities, excellent wear resistance, insulation resistance and other properties. SEBS has a wide range of applications, such as automotive parts, electrical insulating materials, medical materials, adhesives and polymer modifiers, and so on.SEBS is a nonpolar polymer with the less polar and low surfactant, which has defects in the application process such as the poor hydrophilicity, the lack of compatibility and adhesion when used with the polar polymer materials and inorganic filler in common. However, many applications require SEBS providing polarity, such as medical transfusion bags. Therefore, SEBS should take polar modification. Currently, most of the study on modification of the SEBS polarity focused on PS and EB of SEBS main chain. The operations of the work usually have implementation complexity.This paper chooses one kind of SEBS macroinitiators as the material and takes polar modification through the macro radicals’initiation. When SEBS is heated, the macroradicals will appear. The polar groups of modified SEBS have a diversity of designs and we can control the polarity of the monomer species and the mass ratio to reach a good polar effect. A simple operation, no additional processing, high activity, stable action, stable reaction and low cost are the advantage of this method. It has the potential for industrial application.The main contents and results are as follows:1. SEBS macroinitiator is designed and made in the laboratory. A series of explorations that SEBS macroinitiator modified with several polar monomers have been taken by a bulk polymerization process. The results show that the thermal initiation of SEBS macroinitiator can be achieved under the conditions of a reaction temperature higher than 85℃ in 6h. The action can achieved with MMA, HEMA, PEGMA, PEGMEMA, but the best one is PEGMEMA.2. The effects of reaction conditions on the reaction that PEGMEMA are initiated by SEBS macroinitiator have been taken by a bulk polymerization process. The results are as follows:increasing the reaction temperature will improve the content of block component in the polymer. At the reaction temperature 170℃, the reaction hat PEGMEMA are initiated by SEBS macroinitiator chould be achieved in 5 minutes. The time of the reaction can change the block component content little.3. The study of reaction that PEGMEMA are initiated by SEBS macro initiator in the melt polymerization system has been taken, include the reaction temperature, reaction time and the reactive monomer molar ratio. The results are as follows:increasing the reaction temperature and the block monomer molar ratio rising will improve the content of block component in the polymer, but the tensile strength of polymer has more performance degradation. The polar SEBS has an increased polar with a smaller contact angle. However, longer reaction time does little help improve the block component content. The polared SEBS can have an increased polar with a smaller contact angle.4. The study of the reaction between SEBS and both polar monomers has been taken. The results show that SEBS macroinitiator can react with PEGMEMA/GMA and PEGMEMA/PEGMA at the same time.