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首页> 外文期刊>Journal of Applied Polymer Science >Study on synthesis and thermal properties of polyurethane-imide copolymers with multiple hard segments
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Study on synthesis and thermal properties of polyurethane-imide copolymers with multiple hard segments

机译：多硬链段聚氨酯酰亚胺共聚物的合成及热性能研究

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Different multiple hard segment polyurethane-imide copolymers (MHPUI) were synthesized and characterized. FTIR spectroscopy confirmed the characteristic absorption of the MHPUI copolymer. The difference in the imide group FTIR absorption bands in different MH segment PUI copolymers was found in this study and was explained by the different MH segment types, hard segment contents, and hard segment rigidity with different interactions of the molecular chains. The hard segment interaction in MHPUI with an increase of the structure rigidity of the short hard segments is strengthening. The DSC analysis revealed that the glass-transition temperature of the soft segment of PUI rose in value from -42 to -3.4degreesC with the introduction of MH and different TMH segments. The DSC results suggest that the soft segment is more compatible with the hard segment rigidity increase. The TGA results showed the hard segment structure symmetry has a more important role in the MHPUI thermal stability. Every sample containing symmetrical structure short hard groups (4,4'-diphenylmethane diisocyanate or 4,4'-diaminodiphenylmethane) is more thermally stable than that with worse symmetry structure groups (2,4-toluene diisocyanate or 3,3'-diamino-4,4'-diaminodiphenylmethane). The three-step mechanism of PUI thermal degradation was further verified by the TGA study. The thermally unstable group was confirmed as urethane or a urea-urethane segment. The TGA results showed that MHPUI copolymers with higher separation of the soft-hard phase have higher thermal stability. (C) 2002 Wiley Periodicals, Inc. [References: 25]
机译：合成并表征了不同的多硬链段聚氨酯-酰亚胺共聚物（MHPUI）。 FTIR光谱证实了MHPUI共聚物的特征吸收。在这项研究中发现了在不同的MH段PUI共聚物中酰亚胺基团FTIR吸收谱带的差异，并且可以通过分子链相互作用不同的MH段类型，硬段含量和硬段刚性来解释。随着短硬段结构刚度的增加，MHPUI中的硬段相互作用正在加强。 DSC分析表明，随着MH和不同TMH链段的引入，PUI的软链段的玻璃化转变温度从-42℃升高到-3.4℃。 DSC结果表明，软段与硬段刚度的增加更兼容。 TGA结果表明，硬段结构的对称性在MHPUI热稳定性中具有更重要的作用。每个包含对称结构短硬基团（4,4'-二苯基甲烷二异氰酸酯或4,4'-二氨基二苯基甲烷）的样品比具有较差对称结构基团（2,4-甲苯二异氰酸酯或3,3'-二氨基-甲基）的样品更热稳定。 4,4'-二氨基二苯甲烷）。 TGA研究进一步验证了PUI热降解的三步机理。确认热不稳定基团为氨基甲酸酯或脲-氨基甲酸酯链段。 TGA结果表明，软硬相分离度更高的MHPUI共聚物具有更高的热稳定性。 （C）2002 Wiley Periodicals，Inc. [参考：25]

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