TY - JOUR
T1 - Morphology and glass transition behavior of polycarbonate-phenoxy system
T2 - Effects of trans-reactions in domain interface regions
AU - Woo, E. M.
AU - Yau, S. N.
PY - 1997/1/15
Y1 - 1997/1/15
N2 - Effects of trans reactions on the morphology, glass transition, and phase behavior in a classical blend system of a poly(hydroxyl ether bisphenol-A) (phenoxy) with bisphenol-A polycarbonate (PC) were investigated by differential scanning calorimetry (DSC) and optical microscopy. Although two Tgs were observed in the as-prepared PC/phenoxy blends, an apparently single, but broadened. Tg was found in the blends after heating at high temperatures, typically 200-250°C for short times. The optical microscopy results indicated that same scales of heterogeneity did exist in post-heated PC/phenoxy blends as well as unheated blends. Explanations were provided. After heating-induced interchange reactions (- OH and carbonate), randomly linked polymer chains might form at the numerous interfaces of the mutually occluded/included micro-domains. The majority of the chains in the micro-domains are forced to relax in coordinated motion modes after heating, thus showing a single Tg-. A mechanism of trans reactions in interfacial regions was briefly discussed in supplement to earlier reports in the literature.
AB - Effects of trans reactions on the morphology, glass transition, and phase behavior in a classical blend system of a poly(hydroxyl ether bisphenol-A) (phenoxy) with bisphenol-A polycarbonate (PC) were investigated by differential scanning calorimetry (DSC) and optical microscopy. Although two Tgs were observed in the as-prepared PC/phenoxy blends, an apparently single, but broadened. Tg was found in the blends after heating at high temperatures, typically 200-250°C for short times. The optical microscopy results indicated that same scales of heterogeneity did exist in post-heated PC/phenoxy blends as well as unheated blends. Explanations were provided. After heating-induced interchange reactions (- OH and carbonate), randomly linked polymer chains might form at the numerous interfaces of the mutually occluded/included micro-domains. The majority of the chains in the micro-domains are forced to relax in coordinated motion modes after heating, thus showing a single Tg-. A mechanism of trans reactions in interfacial regions was briefly discussed in supplement to earlier reports in the literature.
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U2 - 10.1002/(SICI)1099-0518(19970115)35:1<97::AID-POLA11>3.0.CO;2-9
DO - 10.1002/(SICI)1099-0518(19970115)35:1<97::AID-POLA11>3.0.CO;2-9
M3 - Article
AN - SCOPUS:0030733960
SN - 0887-624X
VL - 35
SP - 97
EP - 103
JO - Journal of Polymer Science, Part A: Polymer Chemistry
JF - Journal of Polymer Science, Part A: Polymer Chemistry
IS - 1
ER -