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  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1449-1455 
    ISSN: 0887-624X
    Keywords: radical copolymerization ; p-t-butoxystyrene ; dibutyl maleate ; penultimate effect ; ESR ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of p-tert-butoxystyrene (TBOSt) (M1) and di-n-butyl maleate (DBM) (M2) with dimethyl 2,2′-azobisisobutyrate (MAIB) in benzene at 60°C was studied kinetically and by means of ESR spectroscopy. The monomer reactivity ratios were determined to be r1 = 2.3 and r2 = 0 by a curve-fitting method. The copolymerization system was found to involve ESR-observable propagating polymer radicals under practical copolymerization conditions. The apparent rate constants of propagation (kp) and termination (kt) at different feed compositions were determined by ESR. From the relationship of kp and f1 (f1 = [M1]/([M1] + [M2])) based on a penultimate model, the rate constants of five propagations of copolymerization were evaluated as follows; k111 = 140 L/mol s, k211 = 3.5 L/mol s, k112 = 61 L/mol s, k212 = 1.5 L/mol s, and k121 = 69 L/mol s. Thus, a pronounced penultimate effect was predicted in the copolymerization. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1449-1455, 1998
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 3121-3130 
    ISSN: 0887-624X
    Keywords: radical cyclopolymerization ; copolymerization ; effect of SnCl4 ; N-allyl-N-phenylmethacrylamide ; N-allyl-N-phenylacrylamide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effects of SnCl4 on the radical polymerization of N-allyl-N-phenylmethacrylamide (APM) and N-allyl-N-phenylacrylamide (APA) were investigated. The polymerizations of APM and APA with dimethyl 2,2-azobisisobutyrate (MAIB) were carried out at 50°C in benzene at various concentrations (0-1.0 mol/L) of SnCl4. The polymerization rates showed a maximum on varying the SnCl4 concentration, while the molecular weights of the resulting poly(APM) and poly(APA) were decreased with increasing SnCl4 concentration. In both systems, the degree of cyclization of polymers were decreased with the SnCl4 concentration. From the IR results, the cyclic structure of the resulting poly(APM)s was confirmed to be five-membered, whereas poly(APA)s contained not only five-membered but also six-membered rings. The 1H-NMR examination on the interactions of APM and APA with SnCl4 revealed that these monomers form 1:1 and 2:1 complexes with SnCl4 with fairly large stability constants. Copolymerizations of APM (M1) with methyl methacrylate (MMA) and styrene (St) (M2) were investigated at 60°C in benzene in the absence of SnCl4. APM units were found to be incorporated exclusively as five-membered rings in the resulting copolymer. Monomer reactivity ratios were estimated to be r1 = 0.29, r2 = 4.88 for APM/MMA and r1 = 0.66, r2 = 5.39 for APM/St. The presence of equimolar (to APM) SnCl4 was found to enhance the reactivity of APM toward poly(MMA) radical; r1 = 0.24, r2 = 2.56. © 1996 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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