105591-47-7Relevant articles and documents
Synthesis of Self-Healing Polymers by Scandium-Catalyzed Copolymerization of Ethylene and Anisylpropylenes
Wang, Haobing,Yang, Yang,Nishiura, Masayoshi,Higaki, Yuji,Takahara, Atsushi,Hou, Zhaomin
, (2019/02/19)
Self-healing materials are of fundamental interest and practical importance. Herein we report the synthesis of a new class of self-healing materials, formed by the copolymerization of ethylene and anisyl-substituted propylenes using a sterically demanding half-sandwich scandium catalyst. The copolymerization proceeded in a controlled fashion, affording unique multi-block copolymers composed of relatively long alternating ethylene-alt-anisylpropylene sequences and short ethylene-ethylene units. By controlling the molecular weight and varying the anisyl substituents, a series of copolymers that show a wide range of glass-transition temperatures (Tg) and mechanical properties have been obtained. The copolymers with Tg below room temperature showed high elastic modulus, high toughness, and remarkable self-healability, being able to autonomously self-heal upon mechanical damage not only in a dry environment but also in water and aqueous acid and alkaline solutions, while those with Tg around or above room temperature exhibited excellent shape-memory property. The unique mechanical properties may be ascribed to the phase separation of the crystalline ethylene-ethylene nanodomains from the ethylene-alt-anisylpropylene matrix.
Selective Demethylative Cyclisation of 2-Methoxy-allylbenzenes
Devakumar, C.,Mukerjee, S. K.
, p. 368 - 372 (2007/10/02)
Treatment of 3-substituted 2-methoxyallylbenzenes with dry HBr in CHCl3 causes selective demethylative cyclisation to give 7-substituted 2-methyl-2,3-dihydrobenzofurans.The reaction involves mutual participation of allyl and 2-methoxyl groups and is sterically accelerated by substituents vicinal to OCH3.The reaction does not take place in high dielectric solvents such as DMF or DMSO.A propable mechanism envisaging a non-classical ionic transition state is proposed and the synthetic utility of this reaction is also demonstrated.