Neodymium tris-diarylphosphates: Systematic study of the structure–reactivity relationship in butadiene and isoprene polymerisation
摘要:
The catalytic properties of neodymium tris-phosphates with various diarylphosphate ligands in the stereoregular 1,4-cis-polymerisation of butadiene and isoprene were studied. The considerable variability of the diaryl phosphate structure allowed for the systematic investigation of the dependence of the catalytic properties of neodymium tris-diarylphosphates on the electronic and steric properties of the ligand. Electron-withdrawing substituents (F, Cl, Br) in the aryl moiety increased the catalyst activity of tris-diarylphosphate. Neodymium aryl phosphates containing lipophilic bulky ligands provided the synthesis of polydienes with a monomodal molecular-weight distribution. The optimal catalytic properties demonstrated that the neodymium aryl phosphate prepared from bis(2,6-dimethy1-4-tert-butylpheny1)phosphoric acid showed high activity and ensured a monomodal MWD of polydienes (M-w/M-n similar to 2 for polybutadiene and M-w/M-n similar to 3 for polyisoprene) in various conditions. (C) 2014 Elsevier B.V. All rights reserved.
A strategy for designing chiralBrønsted base organocatalysts through noncovalent modification of a chiral dibasic molecule with an achiral phosphoric acid diester is introduced for the first time. Such a molecular modification concept utilizing acid-base interactions may facilitate the on-demand design of asymmetric organocatalysts, as preliminarily demonstrated in this work.
An adhesive sheet for dicing comprising a base film provided at least one surface thereof with an adhesive layer, wherein the base film comprises an olefinic thermoplastic elastomer comprising propylene and ethylene and/or &agr;-olefin including 4 to 8 carbon atoms as polymerization components, and the peak melting temperature of the olefinic thermoplastic elastomer is 120° C. or more, is free of economical disadvantages with less reduction in the quality level of products and less generation of fibrous off-cuts during dicing. In particular, fibrous off-cuts occur less during dicing when the base film contains a crystal-nucleating agent. Further, generation of chippings during dicing can be prevented by incorporation of an ethylene series polymer into the base film.
Synthesis of diaryl phosphates using orthophosphoric acid as a phosphorus source
作者:Cong Chi Tran、Kazuya Asao、Takeshi Sasaki、Yasuyuki Hayakawa、Shin-ichi Kawaguchi
DOI:10.1016/j.tetlet.2022.153726
日期:2022.4
This paper presents a new synthetic route for diaryl phosphate esters, which are traditionally synthesized from phosphorus oxychloride. Specifically, we report the synthesis of diaryl phosphates by the dehydrative condensation of orthophosphoric acid, a phosphorus source, with aromatic alcohols.
Method for producing an antibacterial molded article of polyolefin resin
申请人:MITSUBISHI PETROCHEMICAL CO., LTD.
公开号:EP0423604A1
公开(公告)日:1991-04-24
A method for producing an antibacterial molded article of polyolefin resin is described, comprising molding a polyolefin resin composition having compounded therewith 0.01% by weight or more, based on the polyolefin resin composition, of an antibacterial agent containing silver to form a molded article of a desired shape, and thereafter subjecting the antibacterial surface of the molded article to a corona discharge treatment
Disclosed are graft copolymers comprising a propylene polymer material backbone grafted with a mixture of at least two different copolymerizable monomers having improved impact resistance without decrease in clarity.