Preparation of Higher Molecular Weight Poly (L-lactic Acid) by Chain Extension
Joint Authors
Liu, Chenguang
Jia, Yuliang
He, Aihua
Source
International Journal of Polymer Science
Issue
Vol. 2013, Issue 2013 (31 Dec. 2013), pp.1-6, 6 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2013-08-29
Country of Publication
Egypt
No. of Pages
6
Main Subjects
Abstract EN
High molecular weight poly (lactic acid) (PLA) was obtained by chain extending with hexamethylene diisocyanate (HDI).
The influences of the amount of chain extender, reaction time, and molecular weight changes of prepolymers on the poly(lactic acid) were investigated.
PLA prepolymer with a viscosity, average molecular weight (Mη) of 2 × 104 g/mol was synthesized from l-lactide using stannous octoate as the catalyst.
After 20 min of chain extension at 175°C, the resulting polymer had Mw of 20.3 × 104 g/mol and Mn of 10.5 × 104 g/mol.
Both FT-IR and 1H-NMR verified that the structure of PLA did not change either before chain extending or after.
The optically active characterized that the chain extending-product was left handed.
DSC and XRD results showed that both the Tg and the crystallinity of PLA were lowered by chain-extension reaction.
The crystalline transformation happened in PLA after chain extending, crystalline α′ form to α form.
American Psychological Association (APA)
Liu, Chenguang& Jia, Yuliang& He, Aihua. 2013. Preparation of Higher Molecular Weight Poly (L-lactic Acid) by Chain Extension. International Journal of Polymer Science،Vol. 2013, no. 2013, pp.1-6.
https://search.emarefa.net/detail/BIM-462853
Modern Language Association (MLA)
Liu, Chenguang…[et al.]. Preparation of Higher Molecular Weight Poly (L-lactic Acid) by Chain Extension. International Journal of Polymer Science No. 2013 (2013), pp.1-6.
https://search.emarefa.net/detail/BIM-462853
American Medical Association (AMA)
Liu, Chenguang& Jia, Yuliang& He, Aihua. Preparation of Higher Molecular Weight Poly (L-lactic Acid) by Chain Extension. International Journal of Polymer Science. 2013. Vol. 2013, no. 2013, pp.1-6.
https://search.emarefa.net/detail/BIM-462853
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-462853