Catalytic chain transfer for molecular weight control in the emulsion homo- and copolymerizations of methyl methacrylate and butyl methacrylate
UNSPECIFIED. (1997) Catalytic chain transfer for molecular weight control in the emulsion homo- and copolymerizations of methyl methacrylate and butyl methacrylate. JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, 35 (5). pp. 859-878. ISSN 0887-624XFull text not available from this repository.
The behavior of catalytic chain transfer in semi-batch emulsion polymerization has been studied for two monomers, viz, methyl and n-butyl methacrylate. Two different catalytic chain transfer reagents were used with different water solubilities: cobaloxime boron fluoride (COBF), which was found to partition approximately equally between organic and aqueous phases, and tetra-phenyl cobaloxime boron fluoride (COPhBF), which was found to reside predominantly in the organic phase. The difference in hydrophilicity between the two transfer agents was found to affect the polymerization mechanism. COBF exhibited superior transfer behavior in all cases, whereas the restricted mobility of the COPhBF had a deleterious effect on the efficiency of the transfer mechanism. The best results were achieved under monomer flooded conditions using COBF. MALDI-TOF mass spectrometry analysis shows catalytic chain transfer to be the dominant mechanism initiating and stopping chain growth as none of the chains appear to have initiator fragment end groups. Analysis of copolymers by MALDI-TOF mass spectrometry reveals both molecular weight and composition data. (C) 1997 John Wiley & Sons, Inc.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY|
|Publisher:||JOHN WILEY & SONS INC|
|Official Date:||15 April 1997|
|Number of Pages:||20|
|Page Range:||pp. 859-878|
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