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Kānpur, India

Bose S.,Indian Institute of Technology Kharagpur | Mukherjee M.,Indian Institute of Technology Kharagpur | Das C.K.,Indian Institute of Technology Kharagpur | Saxena A.K.,DMSRDE
Polymer Composites | Year: 2010

In this article, the chemistry of interfacial adhesion between different additive systems has been dealt with to develop a high performance nanocomposite and in the process, a comprehensive study on the reinforcing effect of nanosilica has been carried out. The base polymer was considered as the blends of Poly ethersulfone (PES) and thermotropic liquid crystalline polymer (TLCP A novel polymeric compatibilizer, polyphosphazene elastomer, has been utilized and the interchain crosslinking has been explained. Results of experimental investigations demonstrate that the nanofillers play an important role in reducing the interfacial tension. However, the presence of Polyphosphazene elastomer, acted as compatibilizer further reducing the interfacial tension through the inter-molecular interaction. The nanocomposites, thus developed, have better thermal stability and improved rheological properties. In addition, it has also been observed that Polyphosphazene elastomer impart flexibility in the composite. POLYM. COMPOS., 31:543-552, 2010. © 2009 Society of Plastics Engineers. Source

Man-Made Textiles in India | Year: 2012

For realization of fabric into practice with specific intended purpose, we require certain basic cloth calculations pertaining to no of threads per inch, denier of yarn, weight range of fabric and its cover factor to achieve desired aesthetic properties. 'Mathematical Modeling for Fabric Parameter Setting' is a technical article representing the graphical solution (trend lines) based on these fundamental cloth calculations thereby we can select no of threads per inch (warp and weft) in desired denier of yarn to weave a fabric in specific weight (gsm) range and cover factor. In general, we are familiar with the cloth calculations for the conventional textiles fibre i.e. nylon, polyester, acrylic, cotton, wool, etc, where density ranges from 1.0-1.5 and packing fraction of yarn from 0.55-0.65 with moderate cover factor (16-20). But if we want to design a fabric using nonconventional textile fibre (stainless steel fibre) whose density is 7.8 and packing fraction varying from 0.75-0.85, these calculations do not provide practically acceptable information and resulting fabric based on these information is far away than predicted one. This is because the denier of SS yarn is 5.2 times coarser than cotton with similar construction and diameter. So, we need a model to design a fabric in specific weight range and cover factor. In this article, a modeling has been done to predict the no of threads per inch and its denier for the fabric in weight range of 100, 150 and 200 gsm with cover factor of 12, 14, 16 & 18. Source

Hatui G.,Indian Institute of Technology Kharagpur | Sahoo S.,Indian Institute of Technology Kharagpur | Kumar Das C.,Indian Institute of Technology Kharagpur | Saxena A.K.,DMSRDE | And 2 more authors.
Materials and Design | Year: 2012

Nanocomposites of polybutylene terephthalate (PBT) and liquid crystalline polymer (LCP) with either polyphosphazene or nanosilica, or in combination of both were prepared by melt blending. The compatibility between the polymeric phases (PBT&LCP) was observed to be increased by the addition of polyphosphazene while the nanosilica promoted the LCP domain deformation from spherical to ellipsoidal shape. LCP fibres were produced in presence of both polyphosphazene and nanosilica due to the compatibilization of polyphosphazene and bridging effect of nanosilica through hydrogen bonding. All these above structural changes were confirmed by scanning electron microscope (SEM). Transmission electron microscope (TEM) images showed better dispersion of nanosilica in presence of polyphosphazene than nanosilica alone. There is remarkable increase in storage modulus with the addition of nanosilica, individually and in combination with polyphosphazene. Percentages of crystallinity for the concerned nanocomposites were calculated through X-ray diffraction study (XRD). Tensile strength and Young modulus were increased with addition of nanosilica and polyphosphazene but percentage of elongation at break was higher for polyphosphazene added nanocomposite. This is due to flexible compatibilizing effect of polyphosphazene, which delays the detachment of liquid crystalline polymer (LCP) domain from the polybutylene terephthalate (PBT) matrix and thus detains the fracture. © 2012 Elsevier Ltd. Source

Basuli U.,Indian Institute of Technology Kharagpur | Chaki T.K.,Indian Institute of Technology Kharagpur | Setua D.K.,DMSRDE | Chattopadhyay S.,Indian Institute of Technology Kharagpur
Journal of Thermal Analysis and Calorimetry | Year: 2012

Thermal degradation kinetics of MWNT-reinforced EMA-based nanocomposites having different methyl acrylate (MA) contents (by % mass) ranging from 9 to 30% have been monitored. Kissinger and Flynn-Wall-Ozawa methods for evaluating non-isothermal degradation of polymers have been examined. Overall, the thermal stabilities of the nanocomposites are the function of amount of MWNTs loading and their state of dispersion that depends on the MA content of respective EMAs. Composite samples exhibit higher activation energy (Ea) than the neat EMAs but the Eas of the composites diminish with increased MA contents of the matrices. TG-Mass spectrometry has been used to identify the volatile products resulting from thermal degradation of composites, and a promising mechanism has been proposed over different range of temperatures of degradation. It is proposed that the side-group scission of methoxycarbonyl group initiates thermal decomposition following combination of chain end and random chain scission reactions, ensuing pseudo second-order kinetics. © 2011 Akadémiai Kiadó, Budapest, Hungary. Source

Ramani R.,DMSRDE | Alam S.,DMSRDE
Thermochimica Acta | Year: 2010

We report here the investigations on the thermal and thermo-oxidative degradation kinetics of a miscible high performance polymer blend poly(ether ether ketone)/poly(ether imide) (PEEK/PEI) with various compositions, measured in argon and air medium, respectively. The derivative thermogravimetric results indicate two-stage decomposition for both thermal and thermo-oxidative degradation for the entire composition of PEEK/PEI blend. Interestingly, the PEI addition is found to enhance the thermo-oxidation rate of PEEK. The effective activation energy (Eα) as a function of conversion (α) is found for both the processes using model-free kinetics. The model-free kinetics results reveal that the blend with 50% PEI content show high E α value and the differential scanning calorimetry results corroboratively show a significant change in crystallinity for this PEI composition. Based on these results, the blend with composition 50/50 (PEEK/PEI) is suggested to have optimum thermal stability. © 2010 Elsevier B.V. Source

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