Aufsatz in einer Fachzeitschrift
Rheological, Mechanical, Environmental Stress Corrosion and Gamma Resistance Properties of Semi-Crystalline PLA: Effect of Catalysts on the Reactivity of a Chain Extender
Details zur Publikation
Autor(inn)en: | Mamun, M.; Nikousaleh, M.; Heim, H. |
Verlag: | AMER SCIENTIFIC PUBLISHERS |
Publikationsjahr: | 2015 |
Zeitschrift: | Journal of Biobased Materials and Bioenergy |
Seitenbereich: | 285-294 |
Jahrgang/Band : | 9 |
Erste Seite: | 285 |
Letzte Seite: | 294 |
Seitenumfang: | 10 |
ISSN: | 1556-6560 |
DOI-Link der Erstveröffentlichung: |
Zusammenfassung, Abstract
The reaction temperature of the epoxy-based chain extender is higher than 210 degrees C and the reaction kinetic of chain extender is slow. Three catalysts were used to overcome these shortcomings. The catalyst concentrations were optimized and they are 1 wt% for zinc stearate, 3 wt% for N-Methylimidazole and 5 wt% for 1.4-Diazabicyclooctane. The molecular weight of PLA increased during the processing due to addition of chain extender and catalysts. The zinc stearate catalyst showed a minimal effect on the melt rheology, but it promoted crystallinity, the Charpy impact strength (by 29%), and helped to improve the chemical resistance. N-Methylimidazole and 1.4-Diazabicyclooctane catalysts promoted the completion of the chain extension reaction within 2 to 3 minutes with acceptable reaction kinetics that could fulfil the requirements of an industrial compounding process. Afterwards, PLA, the chain extender and optimized content of the catalyst were compounded together using a twin screw extruder. Mechanical, thermal, environmental stress corrosion resistance and gamma radiation resistance properties were investigated for resulting compounds to observe the effects of catalyst.
The reaction temperature of the epoxy-based chain extender is higher than 210 degrees C and the reaction kinetic of chain extender is slow. Three catalysts were used to overcome these shortcomings. The catalyst concentrations were optimized and they are 1 wt% for zinc stearate, 3 wt% for N-Methylimidazole and 5 wt% for 1.4-Diazabicyclooctane. The molecular weight of PLA increased during the processing due to addition of chain extender and catalysts. The zinc stearate catalyst showed a minimal effect on the melt rheology, but it promoted crystallinity, the Charpy impact strength (by 29%), and helped to improve the chemical resistance. N-Methylimidazole and 1.4-Diazabicyclooctane catalysts promoted the completion of the chain extension reaction within 2 to 3 minutes with acceptable reaction kinetics that could fulfil the requirements of an industrial compounding process. Afterwards, PLA, the chain extender and optimized content of the catalyst were compounded together using a twin screw extruder. Mechanical, thermal, environmental stress corrosion resistance and gamma radiation resistance properties were investigated for resulting compounds to observe the effects of catalyst.
Schlagwörter
Catalyst, Chain Extender, Corrosion, Gamma Sterilization, rheological properties
