THE CRYSTALLINITY OF ETHYLENE-VINYLALCOHOL-ACRYLIC ACID TERPOLYMERS
1976 Volume 32 Issue 4 Pages T148-T154
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1976 Volume 32 Issue 4 Pages T148-T154
The physical properties and crystal structure of ethylene-vinylalcohol-acrylic acid terpolymer (EVA-AA: 1_??_10mol% AA content) were investigated by X-ray diffraction method and differential scanning calorimetry.
Following results were obtained: (1) The degree range of crystallinity of EVA-AA was about 15_??_25% which is lower than that obtained of ethylene-vinyl alcohol copolymer (25_??_50%) notwithstanding their nearly similar vinyl alcohol (VA) content. (2) A crystalline region of EVA-AA was partially decomposed by acrylic acid (AA) units. These AA units localized in the amorphous region of EVA-AA like the AA units in vinyl alcoholacrylic acid and ethylene-acrylic acid copolymer. (3) The data gathered from the melting point, d-spacing and copolymer composition showed that the crystalline region of EVA-AA was composed of VA and Et units and that the VA content of EVA-AA in the crystalline phase differed from the overall VA content of the terpolymer
