Organically Modified Montmorillonite as Nanoreactor to Improve the Grafting Degree of Maleic Anhydride onto Polypropylene

Modified polypropylene has been widely used for compatibilization of immiscible polypropylene-polyamide and polypropylene-polyester blends, as well as to improve the interfacial adhesion between polypropylene and glass and carbon fiber, and even as a processing aid for degradable plastics Agent. Functionalized PP has been successfully prepared using solution, melt, and solid-state routes. The melt process has been widely used in industry due to its economic and operational advantages. Montmorillonite has a large surface area, non-hazardous, non-corrosive, low-cost, nano-sized, easy to handle, high stability, and simple processing are the characteristics of MMT. It has nano-layered aluminosilicate clay, in which an octahedral alumina sheet is sandwiched between two tetrahedral silicon sheets, which can be used as a nano-reactor for chemical reactions and a nano-medicine carrier.

In this paper, the application of the organic modified montmorillonite nanoreactor in the reactive extrusion process of maleic anhydride radical grafting to polypropylene (PP) can increase the degree of MAH grafting on PP. The results showed that the strong interaction between MAH and the surface of MMT and the encapsulation effect of active species in o-MMT both increased the degree of grafting.

Figure 1 : TEM micrographs of PP/o-MMT of runs 0, 16 and 21. (a) Trial 0 (PP/o-MMT 40:1 by weight, o-MMT without pretreatment), (b) Trial 21 (PP/o/MMT/DCP/MAH 40:1:1:3 by weight, o- MMT without pretreatment), (c) Trial 16 (PP/(o-MMT/DCP)/MAH 40:2:3 by weight, DCP pre-limited to o-MMT to 1:1 by weight)