توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱CRYSTALLIZATION OF POLY (L–LACTIDE) BIODEGRDABLE POLYMER REINFORCED WITH POLY (L–LACTIDE) GRAFTED MWCNTS
نویسنده(ها): ، ،
اطلاعات انتشار: اولین همایش ملی تکنولوژی های نوین در شیمی و پتروشیمی، سال
تعداد صفحات: ۵
The Poly (L–lactide) (PLLA) biodegradable homopolymer was reinforced with PLLA grafted form MWCNTs (MWCNT–g–PLLA)s. The effect of MWCNT–g–PLLAs on the physical properties of composites was illuminated. The results show that the functionalization of MWCNTs increases the dispersion of MWCNTs in composites and decreases the agglomeration of MWCNTs during preparation of composites. In addition, the results show that the addition of MWCNT–g–PLLAs increases the melting point and crystallinity of the composites. The MWCNTs–g–PLLAs decrease the mobility of matrix chains in amorphous phase of composites. It is predictable that the mechanical performance of composites increases due to two effects: the strength of MWCNTs in composites and the crystallization of PLLA matrix in composites<\div>

۲MECHANICAL PROPERTIES AND THERMAL STABILITY OF MWCNTS\POLYIMIDE NANOCOMPOSITES
نویسنده(ها): ، ، ،
اطلاعات انتشار: اولین همایش ملی تکنولوژی های نوین در شیمی و پتروشیمی، سال
تعداد صفحات: ۵
An aromatic polyimide (PI) with rigid benzoxazole backbone and rigid bulky trifluoromethyl (–CF3) side group has been developed as matrix for in–situ polymerized carbon nanotube (CNT) reinforced nanocomposites. Due to the presence of bulky side group CF3 in the PI backbone, CNTs were carboxylated to engineer the interface between matrix and CNTs by covalent bond. Electron microscopy reveals that a homogeneous dispersion of individual nanotubes in their host PI matrix can be achieved with COOH groups attached on the CNT surface. Fourier transform infrared spectroscopy indicated the formation of covalent bonds between CNTs and PI chains. More significant increase in both elastic modulus and tensile strength was achieved in CNT–COOHs\PI nanocomposites than that of pristine CNT\PI nanocomposite. SEM images of the fracture surface suggest that the COOH groups on the CNT surface improve the nanoscale dispersion of nanotubes in PI matrix and their interfacial adhesion by creating chemical bond between CNTs and PI matrix. The thermal stability of nanocomposites is more greatly enhanced by addition of CNT–COOHs in comparison with pristine CNTs<\div>
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