Macromonomer Synthesized By Atom Transfer Radical Polymerization And Its Capability Research

In this paper, bulk atom transfer radical polymerization (ATRP) of tert-butylmethacrylate (tBMA) was first studied. P-chloromethylstyrene (CMSt) and ethyl-2-bromo-propionate (EPN-Br) were selected as initiators, 2,2'-bipyridyl (bpy) and N,N,N′,N″,N″-Penta-methyldiethylenetriamine (PMDETA) as ligand, with CuCl as catalyst. Poly(tert-butyl methacrylate) with a halogen atom end group PtBMA-X was synthesized by bulk ATRP at 85oC. It was found that initiator and ligand can clearly affect polymerization rate of tBMA monomer based on measurement of molecular weight of PtBMA-X under different initiator/ligand system by using gel permeation chromatography (GPC). The polymerization regulations under different system were compared. The number average molecular weight (Mn) of PtBMA-X could be controlled in a range from 5×103 to 2×104 g/mol by varying the ratio of monomer to initiator(1:50 to1:150), and distribution of molecular weight (Mw/Mn ) kept low than 1.20. The 1H-NMR chemical shifts in parts per million (ppm) were recorded from 0.00 ppm using tetramethylsilane as an internal reference. It was found that obtained PtBMA has a specific structure.Further more, the poly(tert-butyl methacrylate) macromonomer (MAA-PtBMA) with a C=C double end group was successfully prepared by the nucleophilic substitution of halogen atom to methacrylic acid. The introduction rate of double bond could be calculated through the peaks'area of 1H-NMR, the result was high to above 90%. Then, the polymerizations of macromonomers were reseached.Polymeric microspheres were prepared by dispersion copolymerization with macromonomer and styrene in ethanol. In the dispersion copolymerization system, macromonomer make the role of dispersant and co-monomer, the regulation was primary studied. Other more, we attempt to prepare cross-linked PtBMA-PAm microspheres, and the more regulation need be more research.The nucleophilic substitution between polymer chains was discussed. The graft polymers were synthesized and its self-assemble in dissolve was researched. Keywords tert-butyl methacrylate; atom transfer radical polymerization; macromonomer; microsphere...