Journal of Applied Polymer Science, Vol.116, No.5, 2793-2801, 2010
Fluorinated Polypropylene Barrier Materials: Preparation and Characterization
A series of novel fluorinated polypropylenes (FPP) with low surface tension were prepared by reactive extrusion of polypropylene (PP) with fluorinated methacrylate, 2,3,4,5,5,5-hexafluoro-2,4-bis (trifluoromethyl) pentyl methacrylate (HFPMA), aiming at improving the barrier properties of the material for the containers of organic liquids. The surface characteristics of these polypropylene materials and the influence of HFPMA on the crystalline behavior were investigated by the X-ray photoelectron spectroscopy (XPS) and wide-angle X-ray diffraction (WAXD). The surface tension of the FPPs is found to be in the range of 28.8-22.9 mN/m while varying the fluorinated monomer contents, which was lower than that of the original PP (about 30 mN/m). The barrier properties of these materials as the containers were studied by using blow-molded bottles made of FPP and PP. The results showed that enhanced permeation resistance for acetone and xylene solvents as well as better antiultraviolet transmittance properties were achieved in FPP bottles. The acetone and xylene permeation ratio of the FPP bottles were about 1.62 and 1.28 times compared to that of PP bottles, respectively. In addition, the WAXD and DSC studies suggested that the grafting of the fluorinated methacrylate, HFPMA, onto the PP might induce the formation of 13 form crystals, which is rarely found in the common PP materials. The percentage of 1 form crystals reached 33.6%, estimated by WAXD, in the FPP with 20% (by weight) of HFPMA. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2793-2801, 2010