Abstract

This study makes use of polycondensation to produce poly (L-lactic acid)-(polyethylene glycols), a biodegradable copolymer, then puts it with organically modified montmorillonite (o-MMT) going through an intercalation process to produce a series of nanocomposites of PLLA-PEG/o-MMT. The exfoliation and intercalation of the montmorillonite-layered structure could be found through X-ray diffraction and transmission electron microscopy. The lower the molecular weight of poly (ethylene glycol), the more obvious the exfoliation and dispersion. The nanocomposites were investigated under non-isothermal crystallization and isothermal crystallization separately via differential scanning calorimetry (DSC). After the adding of o-MMT to PLLA-PEG copolymers, it was found that the PLLA-PEG nanocomposites crystallized slowly and the crystallization peak tended to become broader during the non-isothermal crystallization process. Furthermore, the thermal curve of the non-isothermal melt crystallization process of PLLA-PEG copolymers with different proportions of o-MMT showed that the melting point decreased gradually with the increase of o-MMT content. In the measurement of isothermal crystallization, increasing the o-MMT of the PLLA-PEG copolymers would increase the t1/2 (crystallization half time) for crystallization and decrease the value of ΔHc. However, the present study results suggest that adding o-MMT could affect the crystallization rate of PLLA-PEG copolymers. The o-MMT silicate layer was uniformly dispersed in the PLLA-PEG copolymers, forming a nucleating agent. The crystallization rate and the regularity of the crystals changed with the increase of the o-MMT content, which further affected the crystallization enthalpies.

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.