The Study On The Synthesis Of Amphiliphic Copolymer Conectworks By ATRP

Amphiphilic polymer networks(APCNs)is a kind of polymer network system connecting by hydrophilic segments and hydrophobic segments through covalent bonds,in which the physical and chemical nature of hydrophilic segments and hydrophobic segments could be remained,respectively.And the two kinds of segments can still be swelling in water and organic solvents,and they aggregated to form micro phase separation.Because of its unique properties,APCNs have got wide application prospects in the fields of intelligent polymer materials,soft corneal contact lens,medical materials and separation materials etc.In recent years,atom transfer radical polymerization(ATRP)has been the hottest research in preparation of high polymers.Through this method,we can obtain size controllable polymers with a relatively narrow molecular weight distribution which can be prepared as APCN prepolymer,which is significant to improve the size uniformity and properties of reslting APCNs.In this paper,the PDMS based macroinitiator and star type initiator are synthesized to initiate the ATRP of amphiphilic block copolymers and star homepolymers.Two kinds of monomers,2-hydroxyethyl methacrylate(HEMA)and N,N-dimethylacrylamide(DMAA),which own good biocompatibility and hydrophilicity are involved as hydrophic segment.And then PDMAAm-b-PDMS-b-PDMAAm,PHEMA-b-PDMS-b-PHEMA and PDMAAm star homo-polymer and PHEMA star homopolymer could be obtained with relatively narrow molecular weight distribution.Then terminal halogen groups of the resulting polymer are modif-ied by allyl amine through nucleophilic substitution or allyl methacrylate was initiatied to obtain allyl end groups.Finally,the desired APCNs could be prepared by hydrosilylation reaction with crosslinker.The main research is descrbed as:(1)Triethanolamine and 2-bromo-isobutyryl bromide were uesed to prepare star ATRP initiator successfully.Hydrogen-terminated silicone oil and ethylene glycol monoallyl ether were used to prepare a high molecular weight hydroxy silicone oil by hydrosilation reaction,PDMS-based macroinitiator was synthesied by reaction between hydroxy silicone oil and 2-bromoisobutyryl bromide.(2)The amphiphilic block polymers PDMAAm-b-PDMS-b-PDMAAm are initiated by PDMS-based macroinitiator and a terminal allyl bromide is formed through its modification.We disscusse the effect of different modifiers,catalyst type,reaction time,reaction temperature,raw ratio and other effects on the modification efficiency.The end groups modified amphiphilic block polymer are reacted with crosslinker to form APCN.Furthermore,the amphiphilic block polymer PHEMA-b-PDMS-b-PHEMA prepared by ATRP provids the prepolymer for the preparation of APCN.(3)The Star PDMAAm and Star PHEMA are synthesized using star initiator successfully prepared by ATRP.We discusse the effect of reaction temperature,catalyst,reaction time,the reaction mass ratio of ATRP polymerization and the end group of star polymers are modified respectively.The study found Star PHEMA can use its active end groups to initiate propyl methacrylate monomer(AMA)polymerization which can be further cross-linked to form APCN,The study finds that the monomer HEMA is more active in ATRP polymerization than the DMAA.We found that hydrophilic swelling properties of APCN prepared by HEMA was less than DMAA.