Segmented Polyurethanes and Thermoplastic Elastomers from Elemental Sulfur with Enhanced Thermomechanical Properties and Flame Retardancy
Segmented Polyurethanes and Thermoplastic Elastomers from Elemental Sulfur with Enhanced Thermomechanical Properties and Flame Retardancy
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DOI：
10.1002/anie.202109115
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发表时间：
2021-09-09
影响因子：
16.6
通讯作者：
Pyun, Jeffrey
中科院分区：
文献类型：
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作者：
Kang, Kyung-Seok;Phan, Anthony;Pyun, Jeffrey
从石油精炼中生产单质硫创造了一个技术机会，通过创造高性能的硫基塑料来提高单质硫的价值，这些塑料具有更好的热机械性能、弹性和阻燃性。我们报告了一种合成聚合方法，以制备硫基分段多块聚氨酯（spu）和热塑性弹性体的第一个例子，该方法将相当数量的硫纳入最终目标材料。该方法采用S-8与烯烃醇的反硫化和与二烯的动态共价聚合制备硫多元醇和三多元醇，用于与芳香族二异氰酸酯和短链二元醇的聚合。利用这些方法，制备了一种新型的高分子量、可溶嵌段共聚物聚氨酯，并通过粒径排除色谱、核磁共振光谱、热分析和显微成像进行了证实。这些硫基聚氨酯很容易被溶液加工成大面积的独立薄膜，其中这些材料的抗拉强度和弹性都由硫多元醇组成的变化控制。制备了具有高拉伸强度（13-24 MPa）和延展性（断裂应变为348%）的SPU，以及与经典热塑性聚氨酯（tpu）相当的SPU热塑性弹性体（断裂应变为578%）。与传统的tpu相比，将硫掺入这些聚氨酯增强了阻燃性，这意味着使用单质硫可以赋予聚合物材料新的性能。
The production of elemental sulfur from petroleum refining has created a technological opportunity to increase the valorization of elemental sulfur by the creation of high-performance sulfur based plastics with improved thermomechanical properties, elasticity and flame retardancy. We report on a synthetic polymerization methodology to prepare the first example of sulfur based segmented multi-block polyurethanes (SPUs) and thermoplastic elastomers that incorporate an appreciable amount of sulfur into the final target material. This approach applied both the inverse vulcanization of S-8 with olefinic alcohols and dynamic covalent polymerizations with dienes to prepare sulfur polyols and terpolyols that were used in polymerizations with aromatic diisocyanates and short chain diols. Using these methods, a new class of high molecular weight, soluble block copolymer polyurethanes were prepared as confirmed by Size Exclusion Chromatography, NMR spectroscopy, thermal analysis, and microscopic imaging. These sulfur-based polyurethanes were readily solution processed into large area free standing films where both the tensile strength and elasticity of these materials were controlled by variation of the sulfur polyol composition. SPUs with both high tensile strength (13-24 MPa) and ductility (348 % strain at break) were prepared, along with SPU thermoplastic elastomers (578 % strain at break) which are comparable values to classical thermoplastic polyurethanes (TPUs). The incorporation of sulfur into these polyurethanes enhanced flame retardancy in comparison to classical TPUs, which points to the opportunity to impart new properties to polymeric materials as a consequence of using elemental sulfur.