cis-polybutadiene was functionalized using in–situ generated dmd as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (ptc). the epoxidation process was investigated by 1hnmr spectroscopy. 1hnmr spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. various factors such as reaction temperature, reaction time and the concentr...

microstructural investigation of low molecular weight 1,4-polybutadiene (1,4-pbd) was studied by 1h and 13c nuclear magnetic resonance spectroscopy (nmr). the isomer contents of 1,4-cis, 1,4-trans and 1,2- vinyl in polybutadiene microstructure were determined. the number average molecular weight for low molecular weight polybutadiene was measured by nmr techniques and comparison was made with g...

Recent shear experiments in well-entangled polymer solutions demonstrated that interfacial wall slip is the only source of shear rate loss and there is no evidence of shear banding in the micron scale gap. In this work, we experimentally elucidate how molecular parameters such as slip length, b, influence shear inhomogeneity of entangled polybutadiene (PBD) solutions during shear in a small gap...

Very small polymer particles of 10-30 nm size with various microstructures (polyethylene, syndiotactic 1,2-polybutadiene, poly(cycloolefins)) are prepared by catalytic polymerization with aqueous catalyst microemulsion.

This presentation provides a brief overview of the production and use of 1,3-butadiene in the United States. Starting as a coproduct of ethylene, the 1,3-butadiene monomer is extracted and purified, then transferred to consumers. Major uses of 1,3-butadiene include the manufacture of styrene-butadiene rubber, polybutadiene rubber, and adiponitrile.

Polybutadiene nanoparticles were synthesized via batch emulsion polymerization of butadiene in the presence of potassium persulfate, disproportionate rosinate potassium cation and t-dodecyl mercaptane as initiator, emulsifier and chain transfer agent, respectively. Polymerization reaction was performed at different temperatures (60, 70 and 80 °C). Conversion was measured at the various time int...

the stereospecific polymerization of conjugated dienes began in 1954 with the first catalysts obtained by combining ticl4 or ticl3 with aluminum-alkyls, i.e. the catalytic systems previously employed for ethylene and propylene polymerizations. subsequently, many other catalytic systems were obtained and examined by a combination of transition metal or lanthanide compounds with appropriate alkyl...

Inelastic helium atom scattering has been used to investigate the vibrational dynamics at the polymer vacuum interface of poly(methyl methacrylate), polystyrene, and polybutadiene thin films on SiO(x)Si(100). Experiments were performed for a large range of surface temperatures below and above the glass transition of these three polymers. The broad multiphonon feature that arises in the inelasti...

Morphology formation during compounding, as well as injection molding of blends containing 60 wt % polycarbonate (PC) and 40 wt % polybutadiene rubber-modified styrene-acrylonitrile copolymers (ABS), has been investigated by transmission electron microscopy (TEM). Profiles of the blend morphology have been recorded in injection-molded specimens and significant morphology gradients observed betw...

The flocculated structure and flow properties of suspensions of brilliant carmine 6B (C6B) in polybutadiene were investigated. In this study, we have used simple suspensions of C6B in polybutadiene having different viscosity. Stress overshoot phenomenon after various rest periods and double-step shearing test were examined for the suspensions. In the double-step shearing test, a transient stres...