| Autor: |
Patanair B; Normandie Univ, UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, France., Saiter-Fourcin A; Normandie Univ, UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, France., Thomas S; School of Chemical Sciences, School of Energy Materials and International and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Priyadarshini Hills P.O, Kottayam, Kerala 686 560, India., Thomas MG; School of Chemical Sciences, School of Energy Materials and International and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Priyadarshini Hills P.O, Kottayam, Kerala 686 560, India., Parathukkamparambil Pundarikashan P; Sree Narayana College, Nattika, Affiliated to the University of Calicut, Kerala 680 566, India., Gopalan Nair K; Sree Narayana College, Nattika, Affiliated to the University of Calicut, Kerala 680 566, India., Kumar VK; Majlis Arts and Science College Puramannur, Malappuram Dist, Kerala 676 552, India., Maria HJ; School of Chemical Sciences, School of Energy Materials and International and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Priyadarshini Hills P.O, Kottayam, Kerala 686 560, India., Delpouve N; Normandie Univ, UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, France. |
| Abstrakt: |
In this paper, the calorimetric response of the amorphous phase was examined in hybrid nanocomposites which were prepared thanks to a facile synthetic route, by adding reduced graphene oxide (rGO), Cloisite 30B (C30B), or multiwalled carbon nanotubes (MWCNT) to lignin-filled poly(lactic acid) (PLA). The dispersion of both lignin and nanofillers was successful, according to a field-emission scanning-electron microscopy (FESEM) analysis. Lignin alone essentially acted as a crystallization retardant for PLA, and the nanocomposites shared this feature, except when MWCNT was used as nanofiller. All systems exhibiting a curtailed crystallization also showed better thermal stability than neat PLA, as assessed from thermogravimetric measurements. As a consequence of favorable interactions between the PLA matrix, lignin, and the nanofillers, homogeneous dispersion or exfoliation was assumed in amorphous samples from the increase of the cooperative rearranging region (CRR) size, being even more remarkable when increasing the lignin content. The amorphous nanocomposites showed a signature of successful filler inclusion, since no rigid amorphous fraction (RAF) was reported at the filler/matrix interface. Finally, the nanocomposites were crystallized up to their maximum extent from the glassy state in nonisothermal conditions. Despite similar degrees of crystallinity and RAF, significant variations in the CRR size were observed among samples, revealing different levels of mobility constraining in the amorphous phase, probably linked to a filler-dimension dependence of space filling. |
