کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
231527 1427427 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Supercritical carbon dioxide-assisted reactive extrusion for preparation long-chain branching polypropylene and its rheology
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Supercritical carbon dioxide-assisted reactive extrusion for preparation long-chain branching polypropylene and its rheology
چکیده انگلیسی

An environmental benign process, which uses supercritical carbon dioxide (ScCO2) as a processing aid, is developed in this work to prepare long chain branching polypropylene (LCB-PP). Results from the oscillatory shear rheology, melt elongational behavior and Fourier transformed infrared spectroscopy (FTIR) show that long chains have been linked as branches to the original linear PP chains using scCO2-assisted reactive extrusion in the presence of cumene hydroperoxide and 1,6-hexanediol diacrylate. Compared to the initial linear PP, the branched samples show higher storage modulus (G′) at low frequency, distinct strain hardening of elongational viscosity, lower melt flow rate, increased crystallization temperature and improvement of the melt strength. ScCO2 can improve the branching efficiency of modified PPs. The elastic response, melt strength and strain hardening parameter of the modified PPs increase with increasing scCO2 concentration, which is ascribed to scCO2 acting as a plasticizer for reducing PP viscosity and a carrier for active chemical species.

Figure optionsDownload as PowerPoint slideResearch highlights▶ An environmental benign process using supercritical carbon dioxide (ScCO2) as a processing aid is developed to prepare LCB-PP. ▶ LCB-PP shows higher storage modulus at low frequency, distinct strain hardening of elongational viscosity, lower melt flow rate, increased crystallization temperature and improvement of the melt strength when compared to linear PP. ▶ ScCO2 can improve the branching efficiency of modified PPs. ▶ The elastic response, melt strength and strain hardening parameter of the modified PPs increase with increasing scCO2 concentration.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Supercritical Fluids - Volume 56, Issue 1, February 2011, Pages 114–120
نویسندگان
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