Polarized SEBS and its preparing mthod

Abstract

The present invention provides a kind of polarized SEBS and its preparation process. The product may be expressed as SEBS-P, where S expresses polystyrene block, EB hydrogenated polybutadiene block, and P polarized block formed via polymerizing polar vinyl pyridine or methacrylate monomer. The preparation process adopts butyl lithium as initiator, tetrahydrofuran as activator and cyclohexane as solvent and includes the steps of the first preparing four block SBS-P polymer, and the subsequent selective hydrogenation to obtain polar SEBS. The present invention produces and polarizes SEBS simultaneously, and thus has high polar monomer converting rate, no need of single treatment of un-converted monomer, simple operation and low production cost. The prepared polar SEBS has obvious polarity, excellent performance, and expanded application field.

Description

technical field [0001] The invention relates to a polarized SEBS and a preparation method thereof. Background technique [0002] Hydrogenated styrene-butadiene-styrene triblock copolymer (SEBS) is a new type of thermoplastic elastomer. A new type of modified elastomer prepared by selective hydrogenation of unsaturated double bonds of butadiene. After hydrogenation, the polybutadiene block in the middle of the hydrogenated SBS is converted into a random copolymerization segment of ethylene and butene-1 and becomes SEBS. Compared with SBS, SEBS has excellent aging resistance, heat resistance and stability, and can be widely used in the production of high-grade elastomers, plastic modification, fillers and sheath materials for wires and cables, etc. Polar materials are limited in application in some fields, especially as plastic modifiers, and have poor compatibility with polar polymers. In order to improve this shortcoming and increase the polarity of SEBS, the patent EP074...

AI Technical Summary

Problems solved by technology

Compared with SBS, SEBS has excellent aging resistance, heat resistance and stability, and can be widely used in the production of high-grade elastomers, plastic modification, fillers and sheath materials for wires and cables, etc. Polar materials, limited applications in some fields, especially as plastic modifiers, poor compatibility with polar polymers

In order to improve this shortcoming and increase the polarity of SEBS, the patent EP0743330 uses a dilithium initiator. After the SBS polymerization is completed, the temperature is lowered, and after the capping agent is added, an anionic polymerizable polar monomer (methyl) is added. Acrylic esters are polymerized at -78°C to obtain polar SBS with polar segments at both ends, and then selectively hydrogenate this polar SBS to obtain SEBS with polar segments. Polar modification is directly carried out in the production process of SEBS, but its polar modification conditions are harsh, the polymer concentration is low, the industrial production output is low, and the production cost is high; in addition, the widely used post-modification method is in the PS section. Sulfonation, acetylation, carboxylation, chloromethylation, methylolation, maleic anhydride of EB segment, esterification of acrylates, etc., carry out graft copolymerization modification by free radical initiation

Such as Jiang Ming et al. ("Chemical Journal of Chinese Universities" 1997, 18 (2), 309-312) adopted to carry out sulfonation modification on the benzene ring of SEBS, heavy etc. ("Journal of Chemical Journal of Chinese Universities" 1995, 20 (5) , 827-829) studied the chloromethylation and hydroxymethylation reactions on the SEBS benzene ring; Guo Yan et al. Refining machine carries out SEBS grafting maleic anhydride reaction; Liu Chengmei et al. Synthetic Resins and Plastics" 2003, 20(4), 51-55) studied the grafting of glycidyl methacrylate (GMA) to SEBS by twin-screw reactive extrusion; there is monomer conversion in this post-modification method Low efficiency, easy cross-linking of products, complex process, high cost and other disadvantages

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