Study On Design And Synthesis Of Polyolefin Macromonomer

Design and synthesis of well-defined polyolefin macromonomer, synthesizing its copolymers with polyolefin side chain via the living copolymerization, play important role in the functionalization of polyolefin. and has broad development and the bright prospect. Herein, by combining living polymerization of ylides and atom transfer radical polymerization (ATRP), two kinds of polyolefin macromonomers and a series of PtBA-g-PM copolymers with controlled molecular weight and narrow molecular weight distributionhave been designed and synthesized.Firstly, a series of hydroxyl terminated polymethylenes (PM-OH) with different molecular weight were prepared using living polymerization of dimethylsolfoxonium methylides following quantitative oxidation via trimethylamine-N-oxide dehydrate (TAO). Then PM-Br was obtained through the reaction of PM-OH with 2-bromoisobutyrate bromide. After that PM-Br reacts with 1,8-Diazabicyclo[5,4,0]undec-7-ene to give polymethylene macromonomer (PM-MM). The ATRP copolymerizations of PM-MM and tert-butyl acrylate (tBA) were performed to obtain a series of well-defined copolymer (PtBA-g-PM). Except that, the synthesis of polymethylene acrylate s macromonomer (PM-AM) by the reaction of PM-OH with acryloyl chloride was preliminarily studied.The molecular chain structure, molecular weight and molecular weight distribution of PM-OH, PM-Br, PM-MM, PM-AM and PtBA-g-PM have been analysized and characterized by'H NMR and high-temperature gel permeation chromatography (GPC). The results show that:1. In the living polymerization of ylides, a certain amount of the branched methyl (2～5mol-%) along the PM's main chain; the chain end functional efficiency of PM-OH can be up to 100% by using the preferred oxidant TAO.2. The polymethylene macromonomer precursor PM-Br was prepared by the transfer reaction of the chain-end hydroxyl of PM-OH. The conversion of functional group can reach 100% in the optimal reaction conditions.3. The polymethylene methacrylate macromonomer PM-MM was obtained by the transfer reaction of PM-Br in about 100% conversion.4. Using methyl-2-bromo propionate (MBP) as initiator, the ATRP copolymerizations of PM-MM and tBAproduce a series of graft copolymers (PtBA-g-PM) with poly(tert-butyl methacrylate) as main chain and polymethylene as side chain Such copolymers have controlled molecular weight and narrow molecular weight distribution.5. A preliminary study was performed and gave polymethlene acrylate macromonomer in about 50% conversion by the direct reaction of PM-OH and acryloyl chloride...