Preparation Of Block Copolymers Using Free Radical Polymerization In The Presence Of 1,1-Diphenylethene

This dissertation was focused on the synthesis of block copolymers by using 1,1-diphenylethene(DPE)radical polymerization system,including the preparation of a series of DPE-containing precursor,and the preparation of block copolymer and star polymer by using these precursor obtained above.Transmission electron microscopy and dynamic light scattering was used to detect the self-assembly behavior of the amphiphilic diblock polymers.The detailed information is as followes:1.Free radical polymerization of methyl methacrylate was carried out with AIBN as initiator in the presence of DPE,giving DPE-containing precursor with controlled molecular weight.The semiquinoid structure of the precursors was confirmed by ~1H NMR spectrum.2.tert-Butyl acrylate(tBA)was polymerized in the presence of PMMA precursor, and PMMA-b-PtBA diblock copolymer with controlled molecular weight was prepared, amphiphilic diblock copolymer PMMA-b-PAA was then obtained by hydrolysis of PMMA-b-PtBA.The formation of PMMA-b-PAA was confirmed by ~1H NMR spectrum and gel permeation chromatography.Transmission electron microscopy and dynamic light scattering were used to detect the self-assembly behavior of the amphiphilic diblock polymers in methanol.3.PMMA-b-PVAc diblock copolymer was prepared by radical polymerization of vinyl acetate(VAc)in the presence of PMMA precursor,with AIBN as initiator.The formation of amphiphilic PMMA-b-PVAc diblock copolymer was confirmed by ~1H NMR spectrum and gel permeation chromatography,and the affect of solvent on the blocking efficiency was studied.This PMMA-b-PVAc block polymer was detected carrying self assembled behavior in methanol.Transmission electron microscopy and dynamic light scattering were performed to measure the self assembled structure of the polymer.4.Acrylic acid was polymerized directly in the presence of PMMA precursor without additional initiator,and amphiphilic diblock copolymer PMMA-b-PAA was obtained directly.The formation of PMMA-b-PAA was confirmed by ~1H NMR spectrum and gel permeation chromatography.Transmission electron microscopy and dynamic light scattering was used to detect the self-assembly behavior of the amphiphilic diblock polymers in methanol.5.Free radical polymerization of tBA was carried out with AIBN as initiator in the presence of DPE,giving DPE-containing precursor with controlled molecular weight. The semiquinoid structure of the precursors was also confirmed by ~1H NMR spectrum. A second monomer was then polymerized in the presence of the precursor obtained above without additional initiator,and a series of PtBA-b-PMMA,PtBA-b-PS diblock copolymer was prepared.Amphiphilic FMMA-b-PAA and PS-b-PAA diblock copolymers were prepared by hydrolysis of the above diblock copolymers. Transmission electron microscopy and dynamic light scattering were performed to measure the size of the self assembled structure of the amphiphilic polymers in THF.6.Free radical polymerization of tBMA was carried out with AIBN as initiator in the presence of DPE,giving DPE-containing precursor with controlled molecular weight. The semiquinoid structure of the precursors was also confirmed by ~1H NMR spectrum. A second monomer was then polymerized in the presence of the precursor obtained above without additional initiator,and a series of PtBMA-b-PMMA,PtBMA-b-PS diblock copolymer was prepared.Amphiphilic PMMA-b-PMAA and PS-b-PMAA diblock copolymers were prepared by hydrolysis of the above diblock copolymers.7.Free radical polymerization of maleic anhydride and styrene was carried out in the presence of DPE,giving Poly(St-alt-MAH)-b-PSt block copolymer;follow by hydrolysis of the block copolymer,a new surfactant was synthesized.This surfactant can be used in suspension polymerization of styrene,and olivary PS white beads.8.Star-shaped copolymers composed of poly(methyl methacrylate)and poly(tert-butyl acrylate)were synthesized by the arm-first method via DPE radical polymerization system.Firstly,free radical polymerization of methyl methacrylate and tert-butyl acrylate were carried out with AIBN as initiator in the presence of DPE, giving DPE-containing PMMA and PtBA precursor.Secondly,the precursor was linked in the presence of DVB,and Star-shaped copolymers were obtained.