分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PB
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-03-30
摘要: A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PB
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-03-30
摘要: A soft segment free thermoplastic polyester elastomer is fabricated by controlling the stereochemical structure of molecular chains with the utilization of the cis 1,4-cyclohexylene ring moiety (cis-CHRM) in poly(butylene 1,4-cyclohexanedicarboxylate) (PB
提交时间: 2017-05-02
摘要: Poly[butylene terephthalate]-poly[tetramethylene glycol] [PBT-PTMG] copolymer is prepared with terephthalic acid [PTA] rather than its dimethyl ester [DMT] as starting material by a two-step melt polycondensation. This process includes the synthesis of PB
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-05-09
摘要: A unique non-planar ring structure 1,4-cyclohexanedicarboxylic acid (CHDA) is introduced to synthesize a poly(butylene adipate-co-butylene 1,4-cyclohexanedicarboxylate) (PBAC) copolyester. The impact of the stereochemistry of CHDA on the structure and properties of PBAC, especially the role of cis-CHDA in tuning the thermal, tensile and elastic properties of PBAC is explored in depth. Instead of considering PBAC as a diblock random copolymer consisting of poly(butylene adipate) (PBA) and poly(butylene 1,4- cyclohexanedicarboxylate) (PBC), our results reveal that PBAC can be considered as a random copolymer consisting of actually three blocks, namely PBA, a PBC unit with only trans-CHDA (trans- PBC), and PBC unit with only cis-CHDA (cis-PBC). The role of cis-CHDA is found to be rigid which initiates a high modulus and strength, and soft which results in a decreased melting temperature and increased elongation at break and elasticity.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Polyurethanes (TPUs) containing carbon–carbon double bonds are synthesized for use as novel materials with the ability to form functionalizable ultrafine fibers via electrospinning. By adjusting the molecular structure, a series of TPU products with different amounts of carbon–carbon double bonds are obtained. After investigating the reactivity of the TPU with 1H,1H,2H,2H-perfluorooctanethiol, all of the TPU samples exhibit effective functionalizability. The more carbon–carbon double bonds contained in the molecular structure, the stronger the functionalizability. Besides, these TPUs can easily form uniform ultrafine fibers via electrospinning. Upon comparison, the functionalizability of the electrospun fibers is similar to that observed in the bulk TPU materials. This work suggests a feasible methodology to produce a functionalized ultrafine fibrous carrier. Accordingly, TPU containing carbon–carbon double bonds is expected to be exploited as a fibrous carrier of solid catalysts in the future.