Process investigating and modelling for the self-polymerization of toluene diisocyanate (TDI)-based polyurethane prepolymer
Process investigating and modelling for the self-polymerization of toluene diisocyanate (TDI)-based polyurethane prepolymer
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DOI：
10.1007/s10853-015-9134-6
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发表时间：
2015-09-01
影响因子：
4.5
通讯作者：
Zhang, Xinya
中科院分区：
文献类型：
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作者：
Guo, Jishuai;He, Yong;Zhang, Xinya
采用甲苯二异氰酸酯（TDI）自聚合法，在不同催化剂和不同温度下制备了TDI型多异氰酸酯预聚体。自聚合过程之后，通过凝胶渗透色谱法来研究单个组分的形成。异氰酸酯基团（-NCO）和游离TDI单体的含量进行了监测，以确认通过返滴定和气相色谱法，分别个别成分的转化。提出了TDI型多异氰酸酯的逐步聚合机理。同时建立了自聚过程各组分含量的数学模型，模拟结果与实验结果吻合较好。采用质谱、傅里叶变换红外光谱和碳13核磁共振谱对多异氰酸酯预聚物的化学结构进行了鉴定和确认。实验结果表明，多个低聚体（包括三聚体、五聚体、七聚体和更高分子量的低聚体）同时存在并相互作用。通过控制反应条件，可以得到TDI型多异氰酸酯预聚物中各组分的理想含量。
Toluene diisocyanate (TDI)-based polyisocyanate prepolymer was prepared via TDI self-polymerization with different catalysts at various temperatures. The self-polymerization process was followed by gel permeation chromatography to investigate the formation of individual components. The contents of isocyanate group (-NCO) and free TDI monomer were monitored to confirm the transformation of individual components through back-titration and gas chromatography, respectively. A step-growth polymerization mechanism for TDI-based polyisocyanate reaction was proposed. Simultaneously, a mathematical model was established to simulate the contents of all components in the self-polymerization process, and the simulated data were in good agreement with the experimental results. Mass spectrometry, Fourier transform infrared spectroscopy and C-13 nuclear magnetic resonance spectroscopy were employed to identify and confirm the chemical structures of the polyisocyanate prepolymer. The experimental results indicate that several oligomers containing trimer, pentamer, heptamer and higher-molecular-weight oligomers presented simultaneously and interacted with each other. The desired content of each component in TDI-based polyisocyanate prepolymer could be obtained by controlling the reaction conditions.