环硫丙烷阴离子可控聚合及富硫共聚物合成策略

doi:10.12141/j.issn.1000-565X.250115

摘要/Abstract

摘要：

环硫化物开环聚合是合成含硫高分子材料的重要方法之一。然而，传统阴离子聚合过程中，高活性硫阴离子容易引发链转移副反应，导致产物出现分子质量分布宽、结构不均一等问题，严重制约了聚合物链段结构的精确调控，影响了材料性能的可设计性和应用的可靠性。针对这一问题，该文基于三乙基硼烷（Et₃B）与磷腈碱 ^t BuP₁协同催化体系，以硫醇为引发剂，成功实现了环硫丙烷的高效可控聚合。实验结果表明：在0℃反应条件下，Et₃B的引入能够抑制硫阴离子向单体及二硫键的链转移副反应；密度泛函理论计算证实，Et₃B通过与硫阴离子活性末端形成稳定的配位作用，显著降低了硫阴离子的亲核反应活性，从而实现了对聚合过程的精准调控。在此基础上，该文提出了“一锅两步”富硫聚合物高效合成策略，采用上述双组分催化体系制备二硫化碳-环硫丙烷交替共聚物，并将其作为大分子链转移剂，通过二次投料，在不分离中间产物的情况下，直接引入苯乙烯单体进行扩链反应，最终成功合成了结构明确的聚苯乙烯-co-聚（二硫化碳-alt-环硫丙烷）三元共聚物，为精确合成富硫聚合物提供了新思路。

关键词: 环硫丙烷, 三乙基硼烷, 阴离子开环聚合, 共聚合

Abstract:

Ring-opening polymerization of cyclic sulfur compounds is one of the important methods to synthesize sulfur-containing polymers. However, in traditional anionic polymerization techniques, the high reactivity of sulfur-centered anions tends to induce chain transfer side reactions, leading to products with broad molecular mass distributions and structural variations. These issues severely restrict the precise control over polymer chain structure and compromise the controllability and reproducibility of material properties. To solve this problem, this study presents a synergistic catalytic system that combines triethylborane (Et₃B), phosphazene base ^t BuP₁ and a thiol initiator to facilitate efficient and controlled anionic ring-opening polymerization of propylene sulfide. Experimental results show that adding Et₃B at 0 ℃ effectively blocks the chain transfer reaction of sulfur anions to monomers and prevents the formation of disulfide bonds. Density functional theory calculations confirm that Et₃B stabilizes the active sulfur-centered anion intermediates through strong B-S coordination, significantly reducing their nucleophilic reactivity and enabling precise control over the polymerization process. Based on these findings, a “one-pot, two-step” strategy for efficient synthesis of sulfur-rich polymers is developed. By using the dual-component catalytic system, an alternating copolymer of carbon disulfide and propylene sulfide can be synthesized as a macro-chain transfer agent, followed by the direct addition of styrene monomer to successfully create a well-defined polystyrene-co-poly(carbon disulfide-alt-propylene sulfide) terpolymer without isolating the intermediate. This work presents a novel pathway for the precise synthesis of sulfur-rich polymers.

Key words: propylene sulfide, triethylborane, anionic ring-opening polymerization, copolymerization

中图分类号:

O633.3

张鸿鑫, 朱鸿轩, 孙都政, 王国胡, 刘奉壮. 环硫丙烷阴离子可控聚合及富硫共聚物合成策略[J]. 华南理工大学学报(自然科学版), 2025, 53(11): 141-149.

ZHANG Hongxin, ZHU Hongxuan, SUN Duzheng, WANG Guohu, LIU Fengzhuang. Controlled Anionic Polymerization of Propylene Sulfide and Strategy for Synthesis of Sulfur-Rich Copolymers[J]. Journal of South China University of Technology(Natural Science Edition), 2025, 53(11): 141-149.

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实验组^1）	引发剂	催化剂	投料比^2）	温度/℃	M_n，thero^3）/（kg·mol^-1）	M_n，SEC^4）/（kg·mol^-1）	Đ_M^4）
PS1	BDM	^t BuP₁	100/1/0.1	25	7.4	30.1/12.8	1.12/1.33
PS2	DODT	^t BuP₁	100/1/0.1	25	7.4	13.5/6.3/2.5	1.04/1.05/1.06
PS3	DODT	DBU	100/1/0.1	25	7.4	16.1/7.2/2.9	1.07/1.06/1.06
PS4	BT	^t BuP₁	50/1/0.1	25	3.7	9.5/3.3	1.07/1.13
PS5	BT	^t BuP₁	50/1/0.1	0	3.7	8.4/3.8	1.04/1.06
PS6	BT	^t BuP₁/Et₃B	50/1/0.1/0.3	0	3.7	4.2	1.05
PS7	DODT	^t BuP₁/Et₃B	100/1/0.1/0.3	0	7.4	10.0	1.07
PS8^5）	BT	^t BuP₁/Et₃B	20/1/0.1/0.3	25		2.7	1.23
PS8^6）	AIBN^7）			65		16.8	1.35