A series of polyurethane (PU) green composites were synthesized with varying amounts, viz. 0, 2, 4, 8, and 12 wt% of soya protein isolate (SPI). Formation of the urethane linkage in the prepared green composites is revealed by infrared spectroscopy. The glass transition temperature (T g ) of the fabricated PU/SPI composites has been evaluated by differential scanning calorimeter. Thermal stability and degradation analysis of the PU/SPI composites have been performed using a thermogravimetric analyzer (TGA). TGA thermograms clearly revealed that the fabricated composites were thermally stable upto 181°C and show a three-step of thermal degradation. The water uptake behaviors of PU/SPI systems have been studied at different chemical environments such as distilled water, salt solution, acidic and alkaline solutions. The microcrystalline parameters such as crystallite size ( N ) and surface weighted crystal size (D s ) have been evaluated from wide-angle X-ray scattering profiles using two different asymmetric distribution functions. PU/SPI green composites were subjected to biodegradation in the presence of Aspergillus niger. The structure-property response of the PU/SPI green composites has been established on the basis of these parameters. C 2016 Wiley Periodicals, Inc. Adv Polym Technol 201 , , 21679; View this article online at wileyonlinelibrary.com.

ABSTRACT:To know the possibility of using Indian butter tree seed waste (mahua seed cake [MSC]) as a filler in the production of value-added product such as polyurethane (PU) green composites, a series of PU composites have been fabricated with varying amounts, namely, 0, 2.5, 5.0, 7.5, and 10 wt%, of MSC, and their effects on the physicomechanical properties such as density, surface hardness, tensile strength, tensile modulus, and percentage elongation at break have been studied. It was found that the tensile strength of the green composites increased from 5.61 to 9.5 MPa and tensile modulus increased from 4.75 to 6.07 MPa with an increase in filler content from 2.5 to 7.5 wt%. The fabricated PU/MSC composites were characterized for structural behavior by Fourier transform infrared spectroscopy and for morphological behaviors by scanning electron microscopy. The chemical resistance of the green composites in different chemical environments has been investigated. The thermal stability and thermal degradation behaviors of composites were performed using thermogravimetric analysis. The microcrystalline parameters such as crystallite size () and lattice strain (g, %) have been computed using wide-angle X-ray scattering data. Based on these parameters, the structure-property relationship of the PU/MSC green composites has been established. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 2015, 0, 21598; View this article online at wileyonlinelibrary.com.

A series of polyurethane (PU) green composites have been synthesized with varying amounts, namely 0, 2, 4, 8, and 12 wt% of soya protein isolate (SPI) by two methods. In the first method, castor oil (CO) and toluene-2,4-diisocyanate (TDI) molar ratio is CO/TDI : 1/1 with varying amounts of the SPI content. In the second method, the molar ratio of TDI is calculated by considering the -OH groups of both CO and SPI. We made the assumption that, in the first method, SPI acts as a filler and in the second method SPI is one of the coreactants in PU formation. The mechanical properties of the fabricated PU/SPI green composites are evaluated; and it is found that the tensile strength increases up to 8 wt% of SPI, and a further increase in SPI leads to reduction in the tensile strength. The small angle x-ray scattering profiles have been used to evaluate the arrangement of amorphous (A) and crystalline (C) regions in the PU/SPI green composites in a scale of about 700 Ǻ by considering the variation in scattered intensity with scattering angles ranging from 0.3°to 1.5°. For this purpose, a linear paracrystalline model is used. In this study, the exponential distribution of phase lengths gives a good agreement between the measured and computed data on the basis of a linear paracrystal model. It is observed that there are significant changes in the distribution of phase lengths due to changes in the composition and chemical structure of PU/SPI composites obtained by methods 1 and 2. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 2016, 35, 21526; View this article online at wileyonlinelibrary.com.

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