Hydrogen phosphates: Self initiated organocatalysts for the controlled ring-opening polymerization of cyclic esters
摘要:
A series of arylhydrogenphosphates and aryldihydrogenphosphates was synthesized and characterized using spectroscopic methods and single crystal X-ray diffraction. These compounds were assessed as catalysts towards the ring-opening polymerization and proved to be potent organocatalysts for the ring-opening polymerization of cyclic esters. The bulk polymerizations were performed in the absence of external initiator. The polymerization proceeds in a controlled fashion which leads to well defined polyesters with narrow molecular weight distributions. In the post polymerization experiments, kinetics, mechanism and monomer concentration effects were investigated. The kinetic results have confirmed the pseudo-living character of the polymerizations and mechanistic studies suggest that the polymerization operates through a cationic mechanism. (C) 2013 Elsevier B.V. All rights reserved.
Hydrogen phosphates: Self initiated organocatalysts for the controlled ring-opening polymerization of cyclic esters
作者:Payal Malik、Debashis Chakraborty
DOI:10.1016/j.ica.2013.02.006
日期:2013.5
A series of arylhydrogenphosphates and aryldihydrogenphosphates was synthesized and characterized using spectroscopic methods and single crystal X-ray diffraction. These compounds were assessed as catalysts towards the ring-opening polymerization and proved to be potent organocatalysts for the ring-opening polymerization of cyclic esters. The bulk polymerizations were performed in the absence of external initiator. The polymerization proceeds in a controlled fashion which leads to well defined polyesters with narrow molecular weight distributions. In the post polymerization experiments, kinetics, mechanism and monomer concentration effects were investigated. The kinetic results have confirmed the pseudo-living character of the polymerizations and mechanistic studies suggest that the polymerization operates through a cationic mechanism. (C) 2013 Elsevier B.V. All rights reserved.
Flame retardance-donated lignocellulose nanofibers (LCNFs) by the Mannich reaction with (amino-1,3,5-triazinyl)phosphoramidates and their properties
nanofibers (LCNFs) by the Mannich reaction. The resulting three-component products were characterized using FT-IR (ATR) and EA. The thermal behavior of the NPCM-treated LCNF fabric samples was determined using TGA and DSC analyses, and their flammability resistances were evaluated by measuring their Limited Oxygen Index (LOI) and the UL-94V test. A multitude of flame retardant elements in the fabric
通过用 POCl 3连续处理 ArOH (Ar = Br n C 6 H 5− n , n = 0, 1, 2, 和 3) 制备了耐久阻燃剂氮/磷三聚氰胺 (NPCM)和三聚氰胺单体。所制备的阻燃剂通过曼尼希反应通过CH 2单元接枝至木质纤维素纳米纤维(LCNF)。使用 FT-IR (ATR) 和 EA 对所得三组分产品进行了表征。使用 TGA 和 DSC 分析确定经过 NPCM 处理的 LCNF 织物样品的热行为,并通过测量其有限氧指数 (LOI) 和 UL-94V 测试来评估其阻燃性。织物样品中的大量阻燃元素使 20 种未经处理的 LCNF 的 LOI 值增加了 45 之多。此外,还用扫描电子显微镜 (SEM) 研究了 NPCM 处理的 LCNF 及其烧焦织物的形态。用锥形量热计观察了 LCNF 织物对水性涂料的放热降低效果。此外,以 NPCM 处理的 LCNF 织物的拉伸强度表示的机械性能表明,PP