Research on Maleic Anhydride Improving the Interfacial Compatibility of PLLA and OMMT by Grafting Method

摘要

Polylactic acid as a biodegradable polymer shows relative high rigidity, but it is brittle and has poor heat resistance, which greatly limits its application. The goal of this experiment is to prepare polylactic acid/organic modified montmorillonite nanocomposite by melting, and to enhance the material properties by improving the interfacial compatibility. First PLLA-g-MAH is prepared through reactive extrusion under initiator dicumyl peroxide, then PLLA/PLLA-g-MAH/OMMT nanocomposite is prepared by melt extrusion. Grafted rate was determined by infrared spectroscopy and chemical titration, and it get to peak when the content of maleic anhydride is 2 wt%. Melt flow rate indicates the nanocomposite has better melt flow and better workability than pure PLA. Mechanical properties of the nanocomposite are best when the content of grafting is 3 wt%. DSC shows that melting temperature and crystallinity of PLLA first increase and then decrease along with the increase of the PLLA-g-MAH, and both of them come to the top when PLLA-g-MAH is 3 wt%.