摘要:

AbstractThe kinetics of radical‐initiated cyclopolymerization of methyl 2‐methylallyl fumarate (MMAF) was investigated and compared with the polymerization results of allyl methyl fumarate (AMF). In the former, the extent of cyclization and five‐membered ring formation were enhanced. The cyclization constantsKAandKV, the ratio of the rate constant of the unimolecular cyclization reaction to that of the bimolecular propagation reaction of the uncyclized 2‐methylallylic and fumaric radicals, were estimated to be 3,1 and 3,0 mol · dm−3, respectively. On the basis of these results the formation mode and the sequence distribution of the structural units of the polymer produced are discussed in detail; the low probability for fumaric vinyl addition and high probability for the succession of cyclic structures are calculated for poly(MMAF) as opposed to those of poly(AMF). The cyclopolymerizability and five‐membered ring formation are enhanced at elevated temperature. These results are discussed from the standpoint of the steric effect on cyclopoly

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870401

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe kinetics of the crosslinking reaction of 4,4′‐[methylenebis(1,4‐phenylene)]‐di‐1,2,4‐triazoline‐3,5‐dione with polybutadienes of narrow molecular weight distribution was studied. At high conversions deviations from the kinetic scheme of a series of first order reactions was observed. The deviations were analyzed by introducing a “retardation” function which includes all informations on the changes in the reaction kinetics. The retardation function was calculated from the experimental data and depends on the polymer concentration and the primary molecular weight. The onset of the deviations in the kinetic behaviour is correlated to the local segment concentration which was calculated assuming unperturbed dimensions of the coils in the semidilute state. Sterical hindrances in the formation of the transition state complex in the gel appear to be of main importance for t

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870402

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractAnionic polymerizations of 2,2,2‐trifluoroethyl acrylate(1a), 2,2,2‐trifluoroethyl methacrylate(1b), 2,2,2‐trifluoro‐1‐trifluoromethylethyl acrylate(2a)and 2,2,2‐trifluoro‐1‐trifluoromethylethyl methacrylate(2b)were carried out with several ate complexes as initiators. LiZnC4H9(C2H5)2was found to initiate the polymerization of methacrylates to produce the corresponding polymers in high yields. LiAlC4H9(C2H5)3also showed appreciably high initiation reactivity for the polymerization of methacrylates. Ate complexes containing alkaline earth metals, except magnesium, were inactive for the polymerization of these four monomers. Polymers of2a, which are generally not obtained with typical anionic initiators such as butyllithium or organomagnesium compounds, were produced with LiAlC4H9(C2H5)3and MgZn(C2H5)4as initiators, though the yield of the polyme

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870403

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractAnionic polymerizations of 2,2,2‐trifluoroethyl acrylate(1a), 2,2,2‐trifluoroethyl methacrylate(1b), 2,2,2‐trifluoro‐1‐trifluoromethylethyl acrylate(2a), and 2,2,2‐trifluoro‐1‐trifluoromethylethyl methacrylate(2b)showing low reactivity toward alkyllithium and alkylmagnesium compounds, were examined with several delocalized anionic initiators. 1,1‐Diphenylhexyllithium, disodium salt of living α‐methylstyrene oligomer, and sodium dihydronaphthylide were found to yield the corresponding polymers of1band2bwith appreciably high conversions. On the contrary, no polymerization conditions were found to produce polymers of1aand2a. The polymerization reactions follow an anionic addition polymerization mechanism, according to the results of1H NMR

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870404

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractCarbonyl groups were found to be present in polymers of 2,3‐epoxypropyl phenyl ether obtained by anionic polymerization. On the basis of quantitative analyses these groups were assumed to be formed in a reaction involving chain transfer to the monomer which proceeds in a manner different from that reported in the literature. Results of the present study were compared with those referring to the polymerization of methyloxirane, phenyloxirane and some chlorophenyl 2,3‐epoxypropyl eth

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870405

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractMetal‐2,9,16,23‐tetracarboxyphthalocyanines(1a — d)(Mt = Fe(III), Co(II), Ni(II) and Cu(II)) were transformed into their acid chlorides2a — dwhich, by Friedel‐Crafts reaction with the benzyl groups of poly(γ‐benzyl‐L‐glutamate)(3), gave the polymers4a — d. The resulting substituted poly(γ‐benzyl‐L‐glutamate)s were found to contain about 0,2 to 2,8 mol‐% of phthalocyanine rings covalently bound to the polymer main chain. Polymers4a — dare soluble in chloroform, 1,4‐dioxane, dichloroacetic acid, DMF etc. The coordination spheres around the metalphthalocyanine rings were characterized by electronic and ESR spectra. The polymers could be shown to have α‐helical conformation, green or blue colored lyotropic mesophases bein

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870406

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractA novel macrocyclic binuclear Cu(II) complex bound to poly(vinylamine) (PVAm) was synthesized by reaction of PVAm withN,N'‐trimethylene bis(3‐formyl‐5‐methylsalicylaldiminato)dicopper (2+) diperchlorate(2)in water/acetone. Polymers containing different amounts of complex repeating units were obtained by varying the amount of2in the reaction mixture. The polymer complexes are soluble in water and methanol. Light‐green colored films were obtained when cast from aqueous solutions. The coordination structure around the macrocyclic complex in the polymer was characterized by infrared and electronic spectroscopy. The Cu — Cu interaction of the binuclear complex on the polymer were also studied by means of ESR

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870407

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractHomopolymerisations of β‐propiolactone and ϵ‐caprolactone, initiated by means of methyl trifluorosulfonate, triethyloxonium tetrafluoroborate or acetylium perchlorate, were investigated. Both1H and13C NMR spectra proved that the alkylating initiators yield polyesters with alkyl ester end groups, indicating a chain growth via alkyl‐oxygen cleavage of the lactone. At temperatures below 100°C cationic polymerizations initiated by alkylating reagents were found to proceed via end groups which may cause degradation due to back‐biting. When ϵ‐caprolactone was reacted with excess methyl triflate, high concentration of triflate ester end groups were formed, whereas in the case of β‐propiolactone active end groups were not detectable by1H NMR spectroscopy. Initiation with acetylium perchlorate yielded a polyester with acetate end groups. Acetate end groups were also obtained, when “living” polymers, initiated with methyl triflate, were reacted with acetic anhydride. It could be shown that the formation of acetate end groups does not indicate an electrophilic attack at the endocyclic oxygen. Furthermore, it is discussed that any experimental evidence for a cationic chain growth via acyloxygen bond

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870408

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractChloramphenicol (1) was immobilized on a hydrogel matrix through different bonds, slowly hydrolyzable at neutral pH. Methacrylic esters of1and its acetal derivatives were prepared and copolymerized with 2‐hydroxyethyl methacrylate. Reactivity ratios and change of copolymer composition with conversion were determined. Bar and disk shaped polymers could be obtained by radical copolymerisation in bulk, which remain colourless and keep their optical properties when swollen to equilibrium in wate

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870409

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractDipotassium polyoxaalkane‐α,ω‐diolates (1–5) and ethylene were found to be formed in the decomposition reaction of solutions of 18‐crown‐6 in tetrahydrofuran containing dissolved potassium. A mechanism of that decomposition process due to the action of the potassium anion

ISSN:0025-116X    

DOI:10.1002/macp.1986.021870410

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY