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
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. %−67 wt.% and a coking value in the range of 57 wt. %−77 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
نویسندگان
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