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Sanchita Bandyopadhyay-Ghosh Subrata B. Ghosh Mohini Sain 《Journal of Polymers and the Environment》2010,18(3):437-442
Soy-polyol has been synthesized via a low energy two-step continuous route thus avoiding intermediate steps and chemicals.
The functional groups of soy-polyol thus produced were identified by Fourier transform infrared (FTIR) spectroscopy which
confirmed the cleavage of the double bonds, the formation of new epoxy linkages and the presence of hydroxyl groups. The change
in chemical structure and physical properties of the soy polyol was further characterized and the results indicated a successful
conversion with reduced unsaturation, increased hydroxyl number and increased viscosity. Polyurethane foam was prepared from
soy-polyol using isocyanate and thermogravimetric analysis was used to study its thermal decomposition behaviour. Multiple
transitions were identified in relation to depolymerization and bond dissociation. Density and compressive strength of the
soy-foam were found to be satisfactory. An investigation of microstructure of soy foam by scanning electron microscope and
X-ray computed tomography revealed the internal cell morphology and cell structure. 相似文献
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S. M. Sharifuzzaman M. Shahadat Hossain Sayedur Rahman Chowdhury Subrata Sarker M. Shah Nawaz Chowdhury M. Zahedur Rahman Chowdhury 《Journal of Coastal Conservation》2018,22(6):1167-1176
Resilience has been conceptualized in various ways by anthropologists, ecologists, systems scientists and engineers; the boundaries of resilience are subjective and context dependent. Consequently, choosing the standards and metrics for assessing resilience remains key challenges for policy makers. In this study, using multicriteria evaluation of 40 basic criteria of human, physical, financial, natural and social assets, we have identified several elements, such as experienced fishermen, natural abundance of hilsa (Tenualosa ilisha), ability to assert decision on fish selling, nets and boats ownership, social harmony and capacity of buying food as essential livelihood assets for the fishermen at Hatiya Island, Bangladesh. These assets may enhance the relative resilience of the fishing community of the island to climate change by as much as 20–40%. The results of this study will improve our understanding of the elements that lead to resilience at the community level. 相似文献
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Bhattacharya Sandipan Das Papita Bhowal Avijit Majumder Subrata Kumar 《Environmental science and pollution research international》2022,29(41):61938-61953
Environmental Science and Pollution Research - Titanium dioxide (TiO2) photocatalyst has gained constant interest in the treatment of wastewater because of its greater stability, lower cost,... 相似文献
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Goswami S Nayak SK Pradhan AC Dey SK 《Journal of environmental biology / Academy of Environmental Biology, India》2011,32(1):105-109
Noise pollution is a significant environmental problem in many rapidly urbanizing areas of Orissa, India. Transportation sector is one of the major contributors to noise in these areas. The present study is an attempt to estimate traffic noise pollution at five places on the way from Vyasa Vihar Campus to Gyan Vigyan Vihar Campus of Fakir Mohan University, Balasore, Orissa. The sources of noise at the studied sites are predominantly attributable to motor vehicular traffic. The noise levels of all the five locations were found to be beyond permissible limit during the day time. The contributions of different types of vehicles to environmental noise were found to ranging from 70.4-94.2, 79.0-96.1, 77.8-110.2, 70.8-90.3, 71.0-87.5, 71.1-84.4, 72.5-86.9 and 74.0-85.4 dB (A) by cargo carrying Trucks, Tractors, Dumpers, Town Buses, Motor cycles, Bolero/Trucker, Pick up and Tempo respectively. The contributions of individual vehicles towards noise pollution were found to be more than the road traffic noise-limit i.e., 70 dB (A). On certain local inhabitants interviewed, the impact of noise was observed in the forms of alterations in their physical, psychological and personal aspects. This study warrants attention from all sections of people to deal with the problem of noise pollution. 相似文献
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Subrata Mondal Paul Memmott Darren Martin 《Journal of Polymers and the Environment》2012,20(2):326-334
In this paper we explore the preparation of polyurethanes from spinifex resin biopolymer. Polyurethanes were prepared by both one-shot and pre-polymer (two step) processes. Attenuated total reflection??Fourier transform infrared analysis revealed urethane bond formation in both processes, and the peak intensity for N?CH stretching was more sharp when the network was prepared by the pre-polymer method. Gel permeation chromatography revealed that the molecular weight of synthesized polyurethane increased with respect to the resin starting material, and the molecular weight was further increased when polyurethane was synthesized by the pre-polymer method. The glass transition temperature was also increased for the polyurethanes as compared with the starting resin. Thermo-gravimetric analysis revealed that the thermal stability of the PU-spinifex resin was reduced at intermediate temperatures due to the urethane bond formation. However, thermal degradation properties were superior at higher temperatures due to the cyclization degradation reaction of spinifex-polyurethane. 相似文献
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Neetu Malik Piyush Kumar Subrata Bandhu Ghosh Sharad Shrivastava 《Journal of Polymers and the Environment》2018,26(8):3243-3249
A range of bio-nanocomposites were prepared by incorporation of organo modified montmorillonite nanoclay (OMMT) with or without use of aluminum hydroxide (Al(OH)3) within polylactic acid (PLA) solution. Furthermore, the solution was employed for modification of ligno-cellulosic (jute) fabric structural reinforcements. The successful incorporation of nanofillers within the host polymer, polylactic acid (PLA) was confirmed by Fourier-transform infrared spectroscopy (FT-IR). Water uptake and swelling behaviour studies revealed that the water uptake and swelling ratio of bio-composites reduced significantly as compared to pristine jute fabric, whereas upon incorporation of OMMT and Al(OH)3, the water barrier properties reduced even further in the developed bio-nanocomposites. The flexural strength of the bio-nanocomposites also showed improved mechanical and dimensional stability. Synergistic effects of OMMT and Al(OH)3 were observed in enhancing the aforementioned physico-mechanical properties. Scanning electron microscopy (SEM) studies revealed microstructural details of developed samples. Similarly, the thermo-gravimetric analysis and linear burning rate studies of Al(OH)3 treated bio-nanocomposite materials revealed enhanced thermal resistance and reduced flammability respectively compared to both pristine woven jute fabric and fabrics treated with PLA alone or those without Al(OH)3. From the above results it can safely be said that the bio-nanocomposite material can be a prospective candidate for development of flame retardant biopackaging. 相似文献
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Arturo U. Rodriguez Subrata B. Ghosh Robert Jeng Mohini M. Sain 《Journal of Polymers and the Environment》2010,18(3):430-436
Starches modified by Ophiostoma spp. have been investigated to develop bio-materials with enhanced mechanical and physical properties for thermoplastic applications.
In this study, glass transition temperature (Tg) of modified starches was investigated in both dynamic mechanical analyzer (DMA) and differential scanning calorimeter (DSC)
to detect molecular changes in the starch’s structure. Overall, two thermal transitions were observed in modified starches,
as opposed to one in their native counterparts. Scanning electron microscopy of granular modified starch indicated visible
damages and internal structural perturbations in addition to occlusion of granular pores by extraneous materials owing to
possible enzymatic degradation and production of secondary metabolites. Modified starches registered two-fold improvement
in storage modulus as compared to that of native starches. From the study of second derivative of the mass loss against temperature,
two thermal transitions were also identified in modified starches. X-ray diffraction analyses showed that crystalline regions
of the starch granules remained intact after the modification. It is proposed that the second phase transition potentially
corresponds to modified amylose fractions and/or exopolysaccharides produced by the fungi. 相似文献