The blends of poly(butylene terephthalate) (PBT) with thermoplastic elastomer (TPE) at a blending... more The blends of poly(butylene terephthalate) (PBT) with thermoplastic elastomer (TPE) at a blending composition of 10–30 wt.% TPE were prepared with an objective to enhance impact toughness of PBT. Two different grades of PBT were selected based on carboxyl end group and viscosity. Melting behavior, mechanical properties, morphology, and rheology of the blends were studied. At all levels of TPE, PBT showed negligible changes in its melting and crystallization temperature; however, percentage crystallinity decreased with an increase in the amount of thermoplastic elastomer. The notched as well as unnotched Izod impact strength of PBT increased with the incorporation of TPE, the increase being about 47% (unnotched) and 54% (notched) with low molecular weight PBT and 18% (unnotched) and 70% (notched) with high molecular weight PBT at 10% TPE level. The tensile strength and tensile modulus of the blends decreased steadily as the weight percent of TPE increased. Analysis of the tensile data using predicted theories indicated that at TPE levels of 30 wt.%, the blends cannot take excessive stress because the interfacial adhesion is lowered. Small angle light scattering (SALS) studies of the samples indicated the decreased rate of crystallization and, hence, an increase in spherulitic radius in the presence of TPE. The increasing incorporation of TPE in PBT/TPE blends increased the shear thinning behavior and hence eased processability.
The objective was to characterize the properties of cellulose nanofibril/TPS based nanocomposites... more The objective was to characterize the properties of cellulose nanofibril/TPS based nanocomposites. The cellulose nanofibrils were extracted from wheat straw using steam explosion, acidic treatment and high shear mechanical treatment. These nanofibrils were dispersed in thermo plastic starch (TPS) using a Fluko high shear mixer in varying proportions and films were casted out of these nanocomposites. The cellulose nanofibrils were characterized using AFM, TEM, SEM, TGA, FTIR and WAXRD and the nanocomposite films were analyzed in terms of SEM, WAXRD, TGA, DSC, mechanical and barrier properties. XRD and TGA results confirmed the crystalline nature of nanofibrils. AFM and TEM images revealed fiber diameter in the range 30-70 nm. TGA depicted an increasing in residue left with increase in cellulose nanofibrils content. Mechanical properties increased with nanofiber concentration. Barrier properties also improved with addition of nanofillers up to 10% but further addition deteriorated properties due to possible fiber agglomeration.
The blends of poly(butylene terephthalate) (PBT) with thermoplastic elastomer (TPE) at a blending... more The blends of poly(butylene terephthalate) (PBT) with thermoplastic elastomer (TPE) at a blending composition of 10–30 wt.% TPE were prepared with an objective to enhance impact toughness of PBT. Two different grades of PBT were selected based on carboxyl end group and viscosity. Melting behavior, mechanical properties, morphology, and rheology of the blends were studied. At all levels of TPE, PBT showed negligible changes in its melting and crystallization temperature; however, percentage crystallinity decreased with an increase in the amount of thermoplastic elastomer. The notched as well as unnotched Izod impact strength of PBT increased with the incorporation of TPE, the increase being about 47% (unnotched) and 54% (notched) with low molecular weight PBT and 18% (unnotched) and 70% (notched) with high molecular weight PBT at 10% TPE level. The tensile strength and tensile modulus of the blends decreased steadily as the weight percent of TPE increased. Analysis of the tensile data using predicted theories indicated that at TPE levels of 30 wt.%, the blends cannot take excessive stress because the interfacial adhesion is lowered. Small angle light scattering (SALS) studies of the samples indicated the decreased rate of crystallization and, hence, an increase in spherulitic radius in the presence of TPE. The increasing incorporation of TPE in PBT/TPE blends increased the shear thinning behavior and hence eased processability.
The objective was to characterize the properties of cellulose nanofibril/TPS based nanocomposites... more The objective was to characterize the properties of cellulose nanofibril/TPS based nanocomposites. The cellulose nanofibrils were extracted from wheat straw using steam explosion, acidic treatment and high shear mechanical treatment. These nanofibrils were dispersed in thermo plastic starch (TPS) using a Fluko high shear mixer in varying proportions and films were casted out of these nanocomposites. The cellulose nanofibrils were characterized using AFM, TEM, SEM, TGA, FTIR and WAXRD and the nanocomposite films were analyzed in terms of SEM, WAXRD, TGA, DSC, mechanical and barrier properties. XRD and TGA results confirmed the crystalline nature of nanofibrils. AFM and TEM images revealed fiber diameter in the range 30-70 nm. TGA depicted an increasing in residue left with increase in cellulose nanofibrils content. Mechanical properties increased with nanofiber concentration. Barrier properties also improved with addition of nanofillers up to 10% but further addition deteriorated properties due to possible fiber agglomeration.
Uploads
Papers by Gaurav Verma