Dibutyl Phtalate Research Articles

Free Volume in Plastified Poly(Vinyl Chlorate)

Positron lifetimes measurements in pure poly(vinyl chlorate) (PVC) and in plastified PVC were performed. Three different plasticizers were used: dibutyl phtalate, dioctyl phtalate and tricresyl phosphate. The measured samples were prepared of PVC with two different plasticizers concentration (20% and 30% of the plasticizers in the poly(vinyl chlorate)). All the measurements were performed in air at room temperature. A conventional fast-slow coincidence lifetime spectrometer was used for the measurements. Free volume radii were calculated from the lifetime data. PACS numbers: 71.60.+z, 78.70.Bj

Study of the effect of hydrogen in propylene polymerization with the MgCl 2-supported ziegler-natta catalyst—part 1. Kinetics of polymerization

Propylene polymerization was investigated with the TiCl 4/MgCl 4 supported catalyst with the stereoregulating donor pair dibutylphtalate (DBPH)/triethoxyphenylsilane (TEPS) in heptane with AlEt 3 as cocatalyst in the presence of hydrogen. It was shown that there is an activation effect by the influence of hydrogen. The removal of hydrogen from the polymerization medium results in an immediate disappearance of activation. However, the deactivation of the system is reversible, and it is possible to repeat the activation effect by hydrogen more than once. It was found that the value of the activation energy is the same in the presence of hydrogen and without it and is equal to 11 kcal/mol. From the experimental results it is concluded that the maximum number of active centres is realized in the catalytic system in the presence of hydrogen, but a value of the propagation rate constant is not changed. It was also found that in the presence of hydrogen the system's decay follows the bimolecular law of active centres deactivation.

An apparatus for dynamic birefringence measurements (abstract)

An apparatus was constructed for simultaneous measurements of the dynamic birefringence and the complex Young’s modulus. The frequency range was 1–200 Hz. The instrument was calibrated with a polybutadiene film, for which the stress‐optical law was expected to hold well. The stress‐optical coefficient estimated by dynamic birefringence measurement was consistent with the result of the static measurement. The stress‐optical law did not hold valid for a polystyrene film containing 5 wt. % dibutyl phtalate in the glass‐to‐rubber transition region.

Tracer diffusion of linear polystyrene in entanglement networks

The diffusion coefficient D tr ∞ of linear PS with M w from 6100 to 2890000 was measured in entanglement networks of PS with much higher M w s in dibutyl phtalate at 30°C by using forced Rayleigh scattering technique. Total polymer concentration C was 13 and 18 wt%, and C of the diffusant was fixed at 1 wt%. D tr ∞ data at C=13 and 18 wt% and also those obtained at 40.6 wt% in an earlier study were found to be superposed on one master curve by using two parameters, an effective friction coefficient of a segment ζ and the molecular weight between entanglements M e , for reduction

アクリル‐アタクチックポリプロピレン‐ワックス系バインダーのＭｏ粉末の射出成形への応用

The injection molding of Mo powder using a Acrylate-APP(atactic-polypropyrene)-Wax binder system was carried out. The molding composition was 54.8%Mo powder, 18.8%Acrylate, 10.9%APP, 11.6%Wax and 3.9%dibutyl phtalate in volume.The green parts were debinded in air, and then specimens were sintered at 1700°C for 19hr in hydrogen gas.The relative density of sintered specimen was 93.0-93.5%.The carbon and oxygen content of sintered specimen were 46 and 224ppm.