Synthesis of crosslinkers based on octa vinyl polyhedral oligomeric silsesquioxane and their flame retardant applications in silicone rubber

IF 7.4 2区化学 Q1 POLYMER SCIENCE Polymer Degradation and Stability Pub Date : 2025-03-26 DOI:10.1016/j.polymdegradstab.2025.111344

Zijian Zheng , Haibo Fan , Wenyuan Zhang , Liang Qiao , Fan Yang , Rongjie Yang , Wenchao Zhang

{"title":"Synthesis of crosslinkers based on octa vinyl polyhedral oligomeric silsesquioxane and their flame retardant applications in silicone rubber","authors":"Zijian Zheng , Haibo Fan , Wenyuan Zhang , Liang Qiao , Fan Yang , Rongjie Yang , Wenchao Zhang","doi":"10.1016/j.polymdegradstab.2025.111344","DOIUrl":null,"url":null,"abstract":"<div><div>It is challenging to improve the flame retardancy and thermal stability of silicone rubber. An effective method was proposed here to solve this problem by incorporating crosslinker made of octa vinyl polyhedral oligomeric silsesquioxane (OV-POSS) into condensed room temperature curing silicone rubber (PDMS). Meanwhile, OV-POSS with different numbers of crosslinking groups were also applied to PDMS and effectively improved its flame retardancy and thermal stability. With the addition of 10 phr nC-POSS (an OV-POSS has an average of n participating click response groups, including 2,4,6,8C-POSS), silicone rubber (SR-nCPOSS) passed the V-0 rating in the vertical combustion test (UL-94) with a high limiting oxygen index (LOI) value of 31–32 %. Moreover, compared with silicone rubber (SR) using tetraethyl orthosilicate, the peak heat release rate was reduced by 46 % and the initial decomposition temperature under nitrogen was increased from 460 °C to 568 °C. In addition, the possible flame-retardant mechanism of nC-POSS, the flame-retardant and catalytic charring effects and free radical quenching effects of PDMS multi-crosslinked networks, were further revealed. The multi-crosslinked network formed by nC-POSS could inhibit the main chain decomposition caused by the terminal hydroxyl group at low temperatures and promote the crosslinking charring of SR, which effectively increased the service temperature of silicone rubber. Moreover, nC-POSS inhibited thermal degradation of SR in the condensed phase and quenches reactive radicals in the gas phase by generating rigid core radicals and phenyl radicals. Our results provide a simple new method for the fabrication of silicone rubber with excellent thermal stability and flame retardancy.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"238 ","pages":"Article 111344"},"PeriodicalIF":7.4000,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Polymer Degradation and Stability","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0141391025001740","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}

引用次数: 0

Abstract

It is challenging to improve the flame retardancy and thermal stability of silicone rubber. An effective method was proposed here to solve this problem by incorporating crosslinker made of octa vinyl polyhedral oligomeric silsesquioxane (OV-POSS) into condensed room temperature curing silicone rubber (PDMS). Meanwhile, OV-POSS with different numbers of crosslinking groups were also applied to PDMS and effectively improved its flame retardancy and thermal stability. With the addition of 10 phr nC-POSS (an OV-POSS has an average of n participating click response groups, including 2,4,6,8C-POSS), silicone rubber (SR-nCPOSS) passed the V-0 rating in the vertical combustion test (UL-94) with a high limiting oxygen index (LOI) value of 31–32 %. Moreover, compared with silicone rubber (SR) using tetraethyl orthosilicate, the peak heat release rate was reduced by 46 % and the initial decomposition temperature under nitrogen was increased from 460 °C to 568 °C. In addition, the possible flame-retardant mechanism of nC-POSS, the flame-retardant and catalytic charring effects and free radical quenching effects of PDMS multi-crosslinked networks, were further revealed. The multi-crosslinked network formed by nC-POSS could inhibit the main chain decomposition caused by the terminal hydroxyl group at low temperatures and promote the crosslinking charring of SR, which effectively increased the service temperature of silicone rubber. Moreover, nC-POSS inhibited thermal degradation of SR in the condensed phase and quenches reactive radicals in the gas phase by generating rigid core radicals and phenyl radicals. Our results provide a simple new method for the fabrication of silicone rubber with excellent thermal stability and flame retardancy.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

八乙烯基多面体低聚硅氧烷交联剂的合成及其在硅橡胶中的阻燃应用

提高硅橡胶的阻燃性和热稳定性是一个具有挑战性的课题。本文提出了一种有效的解决这一问题的方法，即将八乙烯基多面体低聚硅氧烷（OV-POSS）制成的交联剂掺入冷凝室温固化硅橡胶（PDMS）中。同时，将不同交联基团数量的OV-POSS应用于PDMS中，有效提高了PDMS的阻燃性和热稳定性。添加10个单位的nC-POSS（一个OV-POSS平均有n个参与的点击反应组，包括2、4、6、8个c - poss）后，硅橡胶（SR-nCPOSS）通过了垂直燃烧试验（UL-94）的V-0等级，极限氧指数（LOI）高达31 - 32%。此外，与正硅酸四乙酯硅橡胶（SR）相比，峰值放热率降低了46%，氮气作用下的初始分解温度从460℃提高到568℃。此外，还进一步揭示了nC-POSS可能的阻燃机理、PDMS多交联网络的阻燃和催化炭化作用以及自由基猝灭作用。nC-POSS形成的多交联网络可以抑制末端羟基在低温下引起的主链分解，促进SR的交联炭化，有效提高硅橡胶的使用温度。此外，nC-POSS抑制了SR在凝聚相中的热降解，并通过生成刚性核心自由基和苯基自由基来淬灭气相中的活性自由基。我们的研究结果为制备具有优异热稳定性和阻燃性的硅橡胶提供了一种简单的新方法。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

Polymer Degradation and Stability 化学-高分子科学

CiteScore

10.10

自引率

10.20%

发文量

325

审稿时长

23 days

期刊介绍： Polymer Degradation and Stability deals with the degradation reactions and their control which are a major preoccupation of practitioners of the many and diverse aspects of modern polymer technology. Deteriorative reactions occur during processing, when polymers are subjected to heat, oxygen and mechanical stress, and during the useful life of the materials when oxygen and sunlight are the most important degradative agencies. In more specialised applications, degradation may be induced by high energy radiation, ozone, atmospheric pollutants, mechanical stress, biological action, hydrolysis and many other influences. The mechanisms of these reactions and stabilisation processes must be understood if the technology and application of polymers are to continue to advance. The reporting of investigations of this kind is therefore a major function of this journal. However there are also new developments in polymer technology in which degradation processes find positive applications. For example, photodegradable plastics are now available, the recycling of polymeric products will become increasingly important, degradation and combustion studies are involved in the definition of the fire hazards which are associated with polymeric materials and the microelectronics industry is vitally dependent upon polymer degradation in the manufacture of its circuitry. Polymer properties may also be improved by processes like curing and grafting, the chemistry of which can be closely related to that which causes physical deterioration in other circumstances.