| 초록 |
In this study, dicumyl peroxide (DCP) and ethylene glycol (EG) have been selected to induce the crosslinking of PLA for improving melt viscosity by melt processing with an internal mixer. In order to investigate the effect of two modifiers, DCP and EG, on PLA, the mechanical, thermal, and rheological properties of the modified PLA were characterized. Alcohols with different number of reaction centers reduced the PLA molecular weight by alcoholysis. The main advantage of this type of oligomer is that copolymers synthesised in the next step can be crosslinked. Compared to the plain PLA, such modified PLA, showed higher Tg and low crystallization rate because of the crosslinked chain. A significant decrease in the Tm was also observed for increasing DCP content as a result of the introduction of defects in the crystal lamellae by crosslinking after modification. The higher viscosity allowed the production of PLA foams with smaller cell size and lower blowing ratio compare to plain PLA. |
