Matches in SemOpenAlex for { <https://semopenalex.org/work/W1507049999> ?p ?o ?g. }
Showing items 1 to 72 of
72
with 100 items per page.
- W1507049999 endingPage "331" @default.
- W1507049999 startingPage "317" @default.
- W1507049999 abstract "δ Valerolactone and ϵ-caprolactone were reacted with BBr3, AIBr3, TiBr4, SnBr4 or Bu2SnBr2 in dichloromethane or chloroform in a 1 : 1 mole ratio. When these exothermic reactions were conducted with cooling, complexation of the lactones at the exocyclic oxygen was detectable by means of IR and 1H NMR spectroscopy as the first reaction step. However, heating to 60°C causes in all cases ring cleavage, and after hydrolytic removal of the metal bromides ω-bromocarboxylic acids or oligomers with ω-bromoalkanoyl end groups were obtained. SnBr4, Bu2SnBr2 and ZnBr2 proved to be good initiators of the polymerization of both lactones. At low monomer/initiator (M/I)-ratios (high initiator concentrations) most of the initiator remained unchanged, and the average degrees of polymerization of the resulting polylactones largely exceeded the value expected for the M/I-ratio. By means of viscosity and GPC measurements weight-average molecular weights up to 70 000 were found. All polylactones obtained by initiation with these three metal bromides contain ϵ-bromoalkanoyl end groups. Furthermore, high-molecular-weight poly(ϵ-caprolactone) could be prepared at polymerization temperatures up to 150°C. The results do not indicate a cationic polymerization mechanism, but an insertion mechanism involving the metal-O bond formed after the first cleavage of the lactone rings." @default.
- W1507049999 created "2016-06-24" @default.
- W1507049999 creator A5022047822 @default.
- W1507049999 creator A5089699216 @default.
- W1507049999 date "1988-02-01" @default.
- W1507049999 modified "2023-10-10" @default.
- W1507049999 doi "https://doi.org/10.1002/macp.1988.021890207" @default.
- W1507049999 hasPublicationYear "1988" @default.
- W1507049999 type Work @default.
- W1507049999 sameAs 1507049999 @default.
- W1507049999 citedByCount "29" @default.
- W1507049999 countsByYear W15070499992012 @default.
- W1507049999 countsByYear W15070499992014 @default.
- W1507049999 countsByYear W15070499992015 @default.
- W1507049999 countsByYear W15070499992020 @default.
- W1507049999 countsByYear W15070499992023 @default.
- W1507049999 crossrefType "journal-article" @default.
- W1507049999 hasAuthorship W1507049999A5022047822 @default.
- W1507049999 hasAuthorship W1507049999A5089699216 @default.
- W1507049999 hasConcept C111998727 @default.
- W1507049999 hasConcept C158117686 @default.
- W1507049999 hasConcept C166940927 @default.
- W1507049999 hasConcept C178790620 @default.
- W1507049999 hasConcept C183882617 @default.
- W1507049999 hasConcept C185592680 @default.
- W1507049999 hasConcept C188027245 @default.
- W1507049999 hasConcept C203897987 @default.
- W1507049999 hasConcept C2776612806 @default.
- W1507049999 hasConcept C2780400988 @default.
- W1507049999 hasConcept C2780471494 @default.
- W1507049999 hasConcept C2781144210 @default.
- W1507049999 hasConcept C44228677 @default.
- W1507049999 hasConcept C521977710 @default.
- W1507049999 hasConcept C53856295 @default.
- W1507049999 hasConcept C94412978 @default.
- W1507049999 hasConceptScore W1507049999C111998727 @default.
- W1507049999 hasConceptScore W1507049999C158117686 @default.
- W1507049999 hasConceptScore W1507049999C166940927 @default.
- W1507049999 hasConceptScore W1507049999C178790620 @default.
- W1507049999 hasConceptScore W1507049999C183882617 @default.
- W1507049999 hasConceptScore W1507049999C185592680 @default.
- W1507049999 hasConceptScore W1507049999C188027245 @default.
- W1507049999 hasConceptScore W1507049999C203897987 @default.
- W1507049999 hasConceptScore W1507049999C2776612806 @default.
- W1507049999 hasConceptScore W1507049999C2780400988 @default.
- W1507049999 hasConceptScore W1507049999C2780471494 @default.
- W1507049999 hasConceptScore W1507049999C2781144210 @default.
- W1507049999 hasConceptScore W1507049999C44228677 @default.
- W1507049999 hasConceptScore W1507049999C521977710 @default.
- W1507049999 hasConceptScore W1507049999C53856295 @default.
- W1507049999 hasConceptScore W1507049999C94412978 @default.
- W1507049999 hasIssue "2" @default.
- W1507049999 hasLocation W15070499991 @default.
- W1507049999 hasOpenAccess W1507049999 @default.
- W1507049999 hasPrimaryLocation W15070499991 @default.
- W1507049999 hasRelatedWork W1980456244 @default.
- W1507049999 hasRelatedWork W2000319958 @default.
- W1507049999 hasRelatedWork W2002230894 @default.
- W1507049999 hasRelatedWork W2014886209 @default.
- W1507049999 hasRelatedWork W2017105855 @default.
- W1507049999 hasRelatedWork W2067741332 @default.
- W1507049999 hasRelatedWork W2082942974 @default.
- W1507049999 hasRelatedWork W2368644091 @default.
- W1507049999 hasRelatedWork W3194963975 @default.
- W1507049999 hasRelatedWork W975841019 @default.
- W1507049999 hasVolume "189" @default.
- W1507049999 isParatext "false" @default.
- W1507049999 isRetracted "false" @default.
- W1507049999 magId "1507049999" @default.
- W1507049999 workType "article" @default.