کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9559339 | 1381159 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Studies of hydrodynamic properties for characterizing star-shaped poly(ethylene-co-propylene)
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The radius of gyration Rg of (EP)star was found proportional to the molecular weight to a power of 0.34 corroborating a globular architecture and the Rg of (EP)lin to a power of 0.60 indicating a random coil conformation in a good solvent. The intrinsic viscosity [η] of (EP)lin was much higher than that of (EP)star due to the compact globular structure of star molecules. While the [η] of (EP)lin increased with an increase in the molecular weight, the molecular weight had little effect on the [η] of (EP)star as long as the arm length was fixed. Based on the measured Rg and [η], the coefficient q for the scaling law, the Mark-Houwink constant α, and the hydrodynamic radius Re have been calculated. The hydrodynamic radius Re was approximately 0.78 times of Rg for (EP)lin and was nearly identical to Rg for (EP)star. The value of Re/Rg appeared to be independent of the molecular weight for both linear and star polymers and was almost equal to those of polystyrene and polyisoprene in good solvents.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 3, 26 January 2005, Pages 955-963
Journal: Polymer - Volume 46, Issue 3, 26 January 2005, Pages 955-963
نویسندگان
Hsuan-Ming Huang, I-Chun Liu, Raymond Chien-Chao Tsiang,