Abstract Polysiloxane flame retardants have been widely studied because of their high heat resistance and nontoxicity. The flame retardant efficiency may be further improved by inhibiting the release of cyclic siloxanes during combustion. In this study, a novel flame retardant was synthesised by imidisation of an amino-polysiloxane using biorenewable resource-maleopimaric acid (MPA). The MPA inhibits the conversion of polysiloxane to cyclic siloxane, thereby enhancing thermal stability. The synthesised flame retardant was employed as a part of the soft segment to produce rigid polyurethane foam (RPUF) by a “one-pot” process. The rigid MPA and imide groups inhibit the “back-bite” of polysiloxane and promote the formation of a silica-rich hybrid char layer on the backbone of RPUF to reduce flammability. Compared with pure RPUF, the minimum oxygen concentration necessary to support the combustion of modified foam increased by 39.7%, and the peak heat release rate (PHRR) of modified RPUF decreased by more than 50%. Simultaneously, the imide groups and the rigid hydrogenated phenanthrene ring of MPA improved the compressive strength of polysiloxane-modified RPUF. The technique to synthesise a highly effective polysiloxane flame retardant for RPUF is given herein.

中文翻译：

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新型环保马来海松酸基聚硅氧烷阻燃剂及其在硬质聚氨酯泡沫塑料中的应用

摘要 聚硅氧烷阻燃剂由于具有高耐热性和无毒等优点，得到了广泛的研究。通过抑制燃烧过程中环状硅氧烷的释放，可以进一步提高阻燃效率。在这项研究中，使用生物可再生资源马来海松酸 (MPA) 通过氨基聚硅氧烷的酰亚胺化合成了一种新型阻燃剂。MPA 抑制聚硅氧烷向环状硅氧烷的转化，从而提高热稳定性。合成的阻燃剂被用作软链段的一部分，通过“一锅法”生产硬质聚氨酯泡沫 (RPUF)。刚性 MPA 和酰亚胺基团抑制了聚硅氧烷的“回咬”，并促进了 RPUF 骨架上富含二氧化硅的混合炭层的形成，以降低可燃性。与纯RPUF相比，支持改性泡沫燃烧所需的最低氧气浓度提高了39.7%，改性RPUF的峰值放热率（PHRR）降低了50%以上。同时，MPA的酰亚胺基团和刚性氢化菲环提高了聚硅氧烷改性RPUF的抗压强度。本文给出了合成用于RPUF的高效聚硅氧烷阻燃剂的技术。