Abstract

Crystallinity and viscosimetric molecular weights ( Mw v) of four l-lactic acid polymers (PLLA) having different initial molecular weight, i.e. 18 000, 31000, 156000 and 425000, have been determined as functions of the polymer thermal history. Treatments performed in a differential scanning calorimeter (DSC) at various rates showed the different capability of materials to crystallize, due to their different crystallization kinetics and depending on their molecular weight. In the case of cooling from melt, for instance, even at a cooling rate of 0·5 °C/min, only lower molecular weight polymers were able to develop crystallinity. In all materials, moreover, and depending on the initial molecular weight, a parallel degradation effect was observed, which is attributed to thermal cleavage occurring during the treatment.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.