Kang Kyung-Seok, Phan Anthony, Olikagu Chisom, Lee Taeheon, Loy Douglas A, Kwon Minho, Paik Hyun-Jong, Hong Seung Jae, Bang Joona, Parker Wallace O, Sciarra Monia, de Angelis Alberto R, Pyun Jeffrey
Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721, USA.
Department of Polymer Science & Engineering, Pusan National University, Pusan, 46241, Korea.
Angew Chem Int Ed Engl. 2021 Oct 11;60(42):22900-22907. doi: 10.1002/anie.202109115. Epub 2021 Sep 9.
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 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.
石油精炼过程中产生的元素硫创造了一个技术机会，即通过制造具有改善的热机械性能、弹性和阻燃性的高性能硫基塑料来提高元素硫的附加值。我们报道了一种合成聚合方法，用于制备硫基嵌段多嵌段聚氨酯（SPU）和热塑性弹性体的首个实例，这些材料在最终目标材料中掺入了可观量的硫。该方法既应用了硫与烯醇的反向硫化，也应用了与二烯的动态共价聚合，以制备硫多元醇和三元醇，这些多元醇用于与芳族二异氰酸酯和短链二醇的聚合反应。通过尺寸排阻色谱、核磁共振光谱、热分析和显微镜成像证实，使用这些方法制备了一类新型的高分子量、可溶的嵌段共聚物聚氨酯。这些硫基聚氨酯易于通过溶液加工制成大面积的独立薄膜，其中这些材料的拉伸强度和弹性可通过硫多元醇组成的变化来控制。制备了具有高拉伸强度（13 - 24兆帕）和延展性（断裂应变348%）的SPU，以及断裂应变达578%的SPU热塑性弹性体，这些数值与传统热塑性聚氨酯（TPU）相当。与传统TPU相比，将硫掺入这些聚氨酯中增强了阻燃性，这表明由于使用元素硫而有机会赋予聚合物材料新的性能。
