TY - JOUR
T1 - Physical aging in poly(methyl methacrylate)poly(styrene‐co‐acrylonitrile) blends. Part II
T2 - Enthalpy relaxation
AU - Mijović, J.
AU - Ho, T.
AU - Kwei, T. K.
PY - 1989/11
Y1 - 1989/11
N2 - An investigation of the effect of physical aging on excess enthalpy of compatible polymer blends was carried out. Poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (SAN) were chosen for this study. Blends of different ratios of PMMA and SAN were physically aged at different times and temperatures below their glass transition (Tg) and then subjected to enthalpy relaxation measurement in a differential scanning calorimeter (DSC). An improved procedure was developed and, employed to analyze the data. The error associated with the calculation of the normalized deviation in enthalpy, known as the “Φ” function, was below 4%. The relaxation was observed to proceed faster at higher aging temperature. It was also found that at higher aging temperatures of Tg – 20 and Tg– 35°C, enthalpy relaxation in SAN‐rich blends proceeds faster than in PMMA rich blends, while at the low aging temperature of Tg– 50°C the rate of relaxation becomes independent of the composition.
AB - An investigation of the effect of physical aging on excess enthalpy of compatible polymer blends was carried out. Poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (SAN) were chosen for this study. Blends of different ratios of PMMA and SAN were physically aged at different times and temperatures below their glass transition (Tg) and then subjected to enthalpy relaxation measurement in a differential scanning calorimeter (DSC). An improved procedure was developed and, employed to analyze the data. The error associated with the calculation of the normalized deviation in enthalpy, known as the “Φ” function, was below 4%. The relaxation was observed to proceed faster at higher aging temperature. It was also found that at higher aging temperatures of Tg – 20 and Tg– 35°C, enthalpy relaxation in SAN‐rich blends proceeds faster than in PMMA rich blends, while at the low aging temperature of Tg– 50°C the rate of relaxation becomes independent of the composition.
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U2 - 10.1002/pen.760292210
DO - 10.1002/pen.760292210
M3 - Article
AN - SCOPUS:0024767979
SN - 0032-3888
VL - 29
SP - 1604
EP - 1610
JO - Polymer Engineering & Science
JF - Polymer Engineering & Science
IS - 22
ER -