کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7954160 | 1513766 | 2018 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method
ترجمه فارسی عنوان
تهیه و مشخص کردن نقطه نرم کننده بالا و رزین های ایزوتروپیک همگن تولید شده از طر پت اتیلن تقطیر با روش جدید برومین کردن
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
شیمی مواد
چکیده انگلیسی
Homogeneous isotropic pitches with high softening points were prepared from vacuum-distilled heavy residue ethylene tar (ET-HR) by a two-step method of bromination and subsequent dehydrobromination/polycondensation. The ET-HR was first brominated at 30 or 200 oC, and then heat-treated at 350 oC to enable the dehydrobromination/polycondensation reactions. GC/MS and LDI TOF/MS spectra indicated that the ET-HR was mainly composed of compounds containing 3- to 6-ring aromatic species with a considerable aliphatic chain content. Compared with thermal condensation alone, such a two-step method increased the softening point of the pitches from 152 to 264 oC with a yield in the range of 62 wt. %â67 wt.% and a coking value in the range of 57 wt. %â77 wt.%, depending on the bromination temperature and the bromine content. Structural characterization of the as-prepared pitches by elemental analysis, 1H NMR, FT-IR and LDI-TOF/MS showed increased aromatization and polymerization of the precursor during the dehydrobromination/polycondensation. All the homogeneous isotropic pitches showed an ability to transform into an anisotropic texture after coking at 800 °C.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: New Carbon Materials - Volume 33, Issue 1, February 2018, Pages 71-81
Journal: New Carbon Materials - Volume 33, Issue 1, February 2018, Pages 71-81
نویسندگان
Chuan-zhang Ge, Zhen-long Sun, Hai-xiao Yang, Dong-hui Long, Wen-ming Qiao, Li-cheng Ling,