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首页> 外文期刊>Journal of Applied Polymer Science >Synthesis and characterization of novel urethane-siloxane copolymers with a high content of PCL-PDMS-PCL segments
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Synthesis and characterization of novel urethane-siloxane copolymers with a high content of PCL-PDMS-PCL segments

机译：具有高含量PCL-PDMS-PCL链段的新型氨基甲酸酯-硅氧烷共聚物的合成与表征

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Novel polyurethane copolymers derived from 4,4′-methylenediphenyl diisocyanate (MDI), 1,4-butanediol (BD) and α,ω-dihydroxy- [poly(caprolactone)-poly (dimethylsiloxane)-poly(caprolactone)] (α,ω-dihydroxy-(PCL-PDMS-PCL); $ overline M -{m{n}} $ = 6100 g mol~(-1)) were synthesized by a two-step polyaddition reaction in solution. In the synthesis of the polyurethanes, the PCL blocks served as a compatibilizer between the nonpolar PDMS blocks and the polar comonomers, MDI and BD. The synthesis of thermoplastic polyurethanes (TPU) with high soft segment contents was optimized in terms of the concentrations of the reactants, the molar ratio of the NCO/OH groups, and the time and temperature of the polyaddition reaction. The structure, composition, and hard MDI/BD segment length of the synthesized polyurethane copolymers were determined by ~1H, ~(13)C-NMR, and two-dimensional correlation (COSY, HSQC, and HMBC) spectroscopy, while the hydrogen bonding interactions in the copolymers were analyzed by FT-IR spectroscopy. The influence of the reaction conditions on the structure, molecular weight, thermal, and some physical properties was studied at constant composition of the reaction mixture. A change in the molar ratio of the NCO/OH groups and the reaction conditions modified not only the molecular weight of the synthesized polyurethanes, but also the microstructure and therefore the thermal and physical properties of the copolymers. It was demonstrated that only PCL segments with high soft segment contents crystallize, thereby showing spherulitic morphology.
机译：由4,4'-亚甲基二苯基二异氰酸酯（MDI），1,4-丁二醇（BD）和α，ω-二羟基-[聚（己内酯）-聚（二甲基硅氧烷）-聚（己内酯）]衍生的新型聚氨酯共聚物通过溶液中的两步加聚反应合成了ω-二羟基-（PCL-PDMS-PCL）; $ overline M-{ rm {n}} $ = 6100 g mol〜（-1））。在聚氨酯的合成中，PCL嵌段可充当非极性PDMS嵌段与极性共聚单体MDI和BD之间的相容剂。根据反应物的浓度，NCO / OH基团的摩尔比以及加聚反应的时间和温度，优化了具有高软链段含量的热塑性聚氨酯（TPU）的合成。合成的聚氨酯共聚物的结构，组成和硬MDI / BD链段长度通过〜1H，〜（13）C-NMR和二维相关光谱（COSY，HSQC和HMBC）进行测定，同时氢键结合通过FT-IR光谱分析共聚物中的相互作用。在恒定的反应混合物组成下，研究了反应条件对结构，分子量，热和一些物理性质的影响。 NCO / OH基团的摩尔比和反应条件的变化不仅改变了合成聚氨酯的分子量，而且改变了共聚物的微观结构并因此改变了其热和物理性能。已经证明只有具有高软链段含量的PCL链段才能结晶，从而显示出球状形态。

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