The Effect of WS2 Nanosheets on the Non-Isothermal Cold- and Melt-Crystallization Kinetics of Poly(l-lactic acid) Nanocomposites

Abstract

In the present work, hybrid nanocomposite materials were obtained by a solution blending of poly(l-lactic acid) (PLLA) and layered transition-metal dichalcogenides (TMDCs) based on tungsten disulfide nanosheets (2D-WS2) as a filler, varying its content between 0 and 1 wt%. The non-isothermal cold- and melt-crystallization and melting behavior of PLLA/2D-WS2 were investigated. The overall crystallization rate, final crystallinity, and subsequent melting behavior of PLLA were controlled by both the incorporation of 2D-WS2 and variation of the cooling/heating rates. In particular, the analysis of the cold-crystallization behavior of the PLLA matrix showed that the crystallization rate of PLLA was reduced after nanosheet incorporation. Unexpectedly for polymer nanocomposites, a drastic change from retardation to promotion of crystallization was observed with increasing the nanosheet content, while the melt-crystallization mechanism of PLLA remained unchanged. On the other hand, the double-melting peaks, mainly derived from melting–recrystallization–melting processes upon heating, and their dynamic behavior were coherent with the effect of 2D-WS2 involved in the crystallization of PLLA. Therefore, the results of the present study offer a new perspective for the potential of PLLA/hybrid nanocomposites in targeted applications.

Non-Isothermal Crystallization of Titanium-Dioxide-Incorporated Rice Straw Fiber/Poly(butylene succinate) Biocomposites

“…It is necessary to perform melting crystallization during the manufacture of polymers, such as injection, extrusion, or blow molding [ 34 ]. Therefore, a study of the non-isothermal crystallization kinetics has practical significance.…”

Silane functionalization of WS2 nanotubes for interaction with poly(lactic acid)

“…T cc ), the second peak is the melting-recrystallisation of primary thin lamellae at relatively higher temperature. 75 Interestingly, the DSC curves for the composites of APTES modified WS 2 NTs and PLA exhibit a single melting peak at 152 °C, which is attributed to the highly dispersed modified NTs promoting nucleation and PLA crystal growth. However, due to slow crystallisation kinetics of the PLA used in this study, the composites remain almost fully amorphous with a crystalline content remaining below 5%.…”

“…T cc ), the second peak is the melting-recrystallisation of primary thin lamellae at relatively higher temperature [75]. Interestingly, the DSC curves for the composites of APTES modified WS 2 NTs and PLA exhibit a single melting peak at 152 , which is attributed to the highly dispersed modified NTs °𝐶 promoting nucleation and PLA crystal growth.…”

Structural and Morphological Characterization of MEH-PPV/Ag Composite

“…Among these significant polymer classes is poly(2-methox-5(2'-ethylhexyloxy)-1,4-phenylene vinylene (MEH-PPV), which has received a great deal of attention since it was the first PPV to be soluble in commonly used organic solvents [20][21][22][23][24][25][26][27][28][29]. It has been successfully used as a highly efficient light-emitting material in electroluminescence devices.…”