ISSN:
0021-8995
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
The phase behavior of blends of various polymethacrylates with poly(epichlorohydrin) (PECH); poly(ethylene oxide) (PEO); and a copolymer of epichlorohydrin and ethylene oxide [P(ECH/EO)], was examined using differential scanning calorimetery (DSC), dynamic mechanical properties, and optical indications of phase separation on heating, namely lower critical solution temperature (LCST) behavior. Poly(methyl methacrylate) (PMMA), was shown to be miscible with PECH, PEO, and P(ECH/EO), while only PECH was found miscible with the higher polymethacrylates: poly(ethyl methacrylate), poly(n-propyl methacrylate), poly(n-butyl methacrylate), and poly(cyclohexyl methacrylate). However, even PECH was found to be only partially miscible with poly(isopropyl methacrylate). In many cases, unusually broad glass transitions were observed by DSC for blends which are believed to be the result of equilibrium composition fluctuations. All mixtures showed LCST behavior and based on this and excess volume measurements, to the extent possible, qualitative conclusions were made concerning the relative strength of the interactions among the various blend pairs. For PECH, it appears that the interaction with polymethacrylates decreases with increasing size of the alkyl pendant group, with poly(cyclohexyl methacrylate) being a possible exception. The interaction with PMMA is apparently about the same for PECH and PEO, but somewhat less for P(ECH/EO). The latter is consistent with an intrachain attraction of ECH and EO believed to exist. The reasons for similar interactions of PEO and PECH with PMMA are not understood; however, it is clear that the chlorine moiety of PECH is needed for miscibility with higher polymethacrylates.
Zusätzliches Material:
29 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1986.070320618
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