TY - JOUR
T1 - Effect of hot air aging on the properties of ethyleoe-vinyl acetate copolymer and ethylene-acrylic acid copolymer blends
AU - Chen, Shuangjun
AU - Zhang, Jun
AU - Su, Jun
PY - 2009/5/5
Y1 - 2009/5/5
N2 - The aim of this investigation is to evaluate the effect of hot air aging on properties of ethylene-vinyl acetate copolymer (EVA, 14 wt % vinyl acetate units), ethylene-acrylic acid copolymer (EAA, 8 wt % acrylic acid units), and their blends. Attenuated total reflection-Fourier transform infrared spectroscopy, differential scanning calorimeter (DSC), wide angle X-ray diffraction, and mechanical tests are employed to investigate the changes of copolymer blends' structures and properties. Increase of carbonyl index derived from ATR measurements with aging time suggests the incorporation of oxygen into the polymeric chain. By DSC measurements, the enthalpy at low temperature endothermic peak (Tm2) of EAA becomes less and disappears after 8 weeks aging, but enthalpy at Tm2 of EVA is not influenced by the hot air aging and remains stable despite of the aging time. For various proportions of EAA and EVA blends, enthalpy at Tm2 decreases as the EAA proportion increases when aging time is 8 weeks; after several weeks of hot air aging, the various blends appear a same new peak just over the aging temperature 70°C which is due to the completion of crystals which are not of thermodynamic equilibrium state. Mechanical tests show that increase of crystallimty and hot air aging deterioration both have influence on the hardness, tensile strength, and elongation at break.
AB - The aim of this investigation is to evaluate the effect of hot air aging on properties of ethylene-vinyl acetate copolymer (EVA, 14 wt % vinyl acetate units), ethylene-acrylic acid copolymer (EAA, 8 wt % acrylic acid units), and their blends. Attenuated total reflection-Fourier transform infrared spectroscopy, differential scanning calorimeter (DSC), wide angle X-ray diffraction, and mechanical tests are employed to investigate the changes of copolymer blends' structures and properties. Increase of carbonyl index derived from ATR measurements with aging time suggests the incorporation of oxygen into the polymeric chain. By DSC measurements, the enthalpy at low temperature endothermic peak (Tm2) of EAA becomes less and disappears after 8 weeks aging, but enthalpy at Tm2 of EVA is not influenced by the hot air aging and remains stable despite of the aging time. For various proportions of EAA and EVA blends, enthalpy at Tm2 decreases as the EAA proportion increases when aging time is 8 weeks; after several weeks of hot air aging, the various blends appear a same new peak just over the aging temperature 70°C which is due to the completion of crystals which are not of thermodynamic equilibrium state. Mechanical tests show that increase of crystallimty and hot air aging deterioration both have influence on the hardness, tensile strength, and elongation at break.
KW - Blend
KW - Crystallization
KW - Ethylene-acrylic acid copolymer
KW - Ethylene-vinyl acetate copolymer
KW - Hot air aging
UR - http://www.scopus.com/inward/record.url?scp=64249086844&partnerID=8YFLogxK
U2 - 10.1002/app.29506
DO - 10.1002/app.29506
M3 - 文章
AN - SCOPUS:64249086844
SN - 0021-8995
VL - 112
SP - 1166
EP - 1174
JO - Journal of Applied Polymer Science
JF - Journal of Applied Polymer Science
IS - 3
ER -