R. Lakshminarayana Reddy

Miscibility of PVC/PMMA blend by the ultrasonic and refractive index method

The ultrasonic velocity and refractive index of polyvinyl chloride (PVC)/polymethyl methacrylate (PMMA) blend solutions in cyclohexanone have been measured at 30°C. The variation of these parameters with blend composition has been found to be linear, indicating the miscibility of PVC with PMMA. The results obtained have been compared with those obtained by the viscosity method.

Chemical resistance and tensile properties of epoxy/polycarbonate blend coated bamboo fibres

The bamboo fibres belonging to the family of Dendrocalamus strictus were coated with a blend of epoxy/polycarbonate with varying polycarbonate content. The chemical resistance of these fibres to some acids, alkalis and solvents was studied. The tensile load at break for these fibres was determined. The coated fibres showed higher tensile load at break, and were resistant to acids and alkalis. However, the solvent resistance of the coated fibres was found to be minimal.

Ultrasonic, refractometric, and viscosity studies of some polymer blends in solution

The polymer blend solutions of polyvinyl chloride/polystyrene and polyvinyl chloride/cellulose acetate in common solvent have been prepared in different percent of the components. The ultrasonic velocity, viscosity and refractive index have been measured at 30 degrees C The interaction parameters have been computed using the viscosity data to probe the miscibility. The obtained revelations have been confirmed by the ultrasonic velocity and refractive index data.

Chemical Resistance and Tensile Properties of Epoxy/Unsaturated Polyester Blend Coated Bamboo Fibers:

The untreated and 2%aqueous NaOH treated bamboo fibers (Dendrocalamus strictus) were coated with epoxy, unsaturated polyester (UP) and their blends. The chemical resistance of these fibers to acetic acid, nitric acid, hydrochloric acid, sodium hydroxide, ammonium hydroxide, sodium carbonate, benzene, toluene, carbon tetrachloride and water was studied. The blend coated fibers showed better resistance to the chemicals mentioned above. The blend coated fibers had higher tensile strength. This was attributed to the hydrogen bonding between the unsaturated polyester and epoxides group.

Infrared spectroscopic investigation of some polymers and polymer blend films irradiated by a 28Si ion beam

Abstract Films of polypropylene, polyimide, and a polymethyl methacrylate/polystyrene (PMMA/PS) blend were irradiated with a 28Si ion beam of 60 MeV. The infrared (IR) spectra of these samples before and after irradiation were recorded and, using the spectral information, some structural changes were investigated. The spectra indicated crosslinking in polypropylene, and stability, ordering and conformational changes in polyimide. Based on the infrared spectra, PMMA was found to degrade whereas PS was found to crosslink in the blend after irradiation. Further the IR spectra of the blend film before and after irradiation did not reveal any interaction between PMMA and PS showing the immiscible nature of the blend.

Tensile Properties of Glass-Mat Reinforced Polycarbonate Toughened Epoxy Composite

Epoxy was toughened with polycarbonate in different proportions. Woven glass mat was reinforced into this matrix. The variation of tensile strength with varying mat content and polycarbonate content was studied. The tensile strength of the composites was found to be higher than that of the matrix. Further, the tensile strength of both the composite and the matrix increased with polycarbonate content of up to 10%, beyond which it decreased. The tensile strength for 20% volume content of the glass-mat was found to be maximum when reinforced in both epoxy and blend matrices.

Miscibility of Polycarbonate/Polyvinylpyrrolidone and Polycarbonate/Polyethylene Oxide in Chloroform by Viscosity, Ultrasonic and Refractometric Methods

Abstract Miscibility studies of polycarbonate/polyvinylpyrrolidone (PC/PVP) and polycarbonate/ polyethylene oxide (PC/PEO) in common solvent chloroform were carried out in different percentages of the blend compositions. The viscosity, ultrasonic velocity, refractive index and density were measured at 30[ddot]C. The interaction parameters were obtained using the viscosity data to probe the miscibility. The obtained results were confirmed by the ultrasonic velocity, density and refractive index measurements.

Infrared spectroscopic investigation of polymethyl methacrylate/polyvinyl chloride blend films irradiated by a 28Si ion beam

Abstract The films of polymethyl methacrylate/ polyvinyl chloride blends of different compositions have been prepared. They have been irradiated with a 28Si ion beam of 120 MeV in the fluence range of 1011–1013 ions/cm2. The infrared spectra of these samples have been recorded before and after irradiation and based on the spectral information, some structural changes in the films have been found.

Effect of 28Si ion radiation on polymer blend

Abstract The polymer blends of Polymethyl Methacrylate/Polystyrene (PS/PMMA) have been irradiated with 28 Si ions of 60 MeV. The percentage transmission of light in the wavelength region of 490 nm has been studied with varying concentration of PS in blend films before and after irradiation. The transmission of light increased on irradiation which may be attributed to the chain scissions of PMMA.

Miscibility Studies of Polycarbonate/ Poly(methyl methacrylate) and Polycarbonate/Polystyrene Blends as Measured by Viscosity, Ultrasonic, and Refractive Index Methods

Abstract The ultrasonic velocity, viscosity, refractive index and density of polycarbonate/poly-(methyl methacrylate) (PC/PMMA) and polycarbonate/polystyrene (PC/PS) blends in solution have been measured at 30°C. Using the viscosity data, the interaction parameters have been computed which indicate that the PC/PMMA blend is miscible, whereas the PC/PS is immiscible. This is confirmed by ultrasonic and refractive index measurements.