کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5210386 | 1382891 | 2011 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Chain homogeneity and thermo-mechanical behaviour of polyphosphazenes. Synthesis of the random copolymers {[NP(O2C12H8)1âx[NP(OCH2CF3)2]x}n
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Chain homogeneity and thermo-mechanical behaviour of polyphosphazenes. Synthesis of the random copolymers {[NP(O2C12H8)1âx[NP(OCH2CF3)2]x}n Chain homogeneity and thermo-mechanical behaviour of polyphosphazenes. Synthesis of the random copolymers {[NP(O2C12H8)1âx[NP(OCH2CF3)2]x}n](/preview/png/5210386.png)
چکیده انگلیسی
The phosphazene homo and copolymers combining the λ5-phosphorus-dioxy-biaryl units [NP(O2C12H8)] or {[NP(O2C20H12)]n (O2C12H82,2â²-dioxy-1,1â²-biphenyl, O2C20H12 = R or R/S-2,2â²-dioxy-1,1â²-binaphthyl) and the conventional units [NP(OC6H4CO2Pr)2] or [NP(OCH2CF3)2], including the new series {[NP(O2C12H8)]1âx[NP(OCH2CF3)2]x}n (x = 0-1), all prepared by alkali carbonate assisted sequential macromolecular substitution from [NPCl2]n have been studied by DSC-assisted thermo mechanical analysis. The results showed that the thermal expansion coefficient changes in dilatation mode and the softening temperature in the compression mode are coincident with the glass transition temperatures (Tg) as measured by DSC except for the random copolymers containing the λ5-phosphorus-dioxy-biaryl units in the approximate interval 40-60% for which the softening temperatures were much higher. For the chiral polymers with [NP(O2C20H12)]n units, the TMA differences between the isomers R, R/S and the atactic products formed by their thermal atropisomerisation near the Tg suggest that the R/S product resulting in the macromolecular substitution from [NPCl2]n and rac-binaphthol may have some degree of tacticity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Reactive and Functional Polymers - Volume 71, Issue 4, April 2011, Pages 433-439
Journal: Reactive and Functional Polymers - Volume 71, Issue 4, April 2011, Pages 433-439
نویسندگان
Gabino A. Carriedo, Beatriz Ramajo, M.L. Valenzuela,