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Kinetics of phase dispersion of binary blends of polypropylene and poly(cis-butadiene) rubber during the processing in a batch mixer was investigated by a back small-angle laser scattering (BSALS) online system. It was found experimentally that the scattering intensity I(q, t) followed an exponential growth with time during the early dispersion stage from 1 s to 65 s, while at t > 65 s, the slope levels off with time. A theory in which two critical parameters, W(q) and Dd, were calculated was proposed to describe the early stage of phase dispersion; the former parameter is defined as the rate of decreasing dispersed phase dimension, and the latter, evaluated from the slope of W(q) versus q2 plot, is the dispersion coefficient. W(q) remains constant with the increment of dispersed phase. W(q) has a self-similarity with q for different compositions. The slope β, defined as the dispersion acceleration evaluated by linear fit in the nonscaling interval, was determined to explain the similar evolution mechanisms for the different velocity distributions of W(q). The dispersion coefficient Dd increases with the increment of the dispersed phase, and does not vary with shear rates. [ABSTRACT FROM AUTHOR]

Dynamic scaling and fractal behavior of phase dispersion in a binary polymer mixture of polypropylene with poly(cis-butadiene) rubber during processing in a batch mixer was studied by means of a back small-angle laser scattering (BSALS) online system. In the late stage of phase dispersion, a special fractal behavior was found; different overlapped line groups existed simultaneously and the temporal distribution was stochastic. We defined the special behavior as quasi-self-similarity and calculated the fractal dimension, Dp, by using the power spectrum method. The results show that the evolution of different fractal dimensions with time is consistent with average chord length of the dispersed phase. [ABSTRACT FROM AUTHOR]

Functional microorganisms to high concentration phenol containing Cr^{6+} and Pb^{2+} were cultured and biofilm was formed on polypropylene packings in bioelectro-reactor. It was found that the biodegradation capability of such biofilm to phenol changed with the applied voltage. Under the optimal electric field conditions (voltage of 3.0 V, electric field of strength 17.7 V/m and current density of 1.98 A/m^2), biodegradation efficiency of phenol aof concentration of 1200 mg/L increased 33% compared to the instance without applying electric field. However, voltage had inverse effect on biodegradation, as microorganisms were killed under strong electric field. Voltage had little effect on heavy ions elimination. Higher absorption rate of Cr^{6+} and Pb^{2+} was observed when changing pH from acidic to neutral. The experiment results indicated that, after treatment, 10 L phenol of 2400 mg/L was biodegraded completely within 55 h and concentrations of Cr^{6+} and Pb^{2+} dropped to less than 1 mg/L within 12 h and 6 h, from initial values of 50 mg/L and 30 mg/L, respectively. [ABSTRACT FROM AUTHOR]