The crystallization morphology of poly(phenylene sulphide) (PPS) with different molecular weights (MW), isothermally crystallized from the melt under Shear condition, has been observed by polarized optical microscope (POM) equipped with a CSS450 hot-stage. The morphology of PPS is greatly influenced by Shear condition, and the shish-kebab-like fibrillar crystal structure can be observed under higher Shear rate and longer Shear time for the higher molecular weights. Under the quiescent crystallization the growth rate was found to be essentially MW dependent i.e., the spherulite growth rate decreases with the increased MW, and a strong effect of MW on the flow induced crystallization kinetics was observed. Under Shear condition the decreasing spherulite growth rate results from highly oriented chains. The molecular weight was also found to explain qualitatively the observed transition from the lowest MW isotropic morphology to the higher MW shish-kebab-like fibrillar crystal structure. The melting behaviors of the three MWs performed by differential scanning calorimetry (DSC) show that multiple melting peaks can be observed after the PPS melts when subjected to Shear flow. We suggest that the lower melting peak corresponds to the melt of imperfect crystal. The higher melting peak is related to the orientation of molecular chains. These orientated molecular chains form the initial lamellae, which are thicker than the kebab-like lamellae that later develop due to chain relaxation.

Background: Some plant extracts can prevent kidney stone formation in a dosedependent manner. In our study, we aimed to investigate the protective role of Cannabis sativa aqueous extraction on calcium oxalate formation in ethylene glycolinduced rats. Materials and Methods: To evaluate anti-urolithiasis, variations of the main risk factors (citrate, phosphorous, calcium, and Ph) have been evaluated in 24-hour urine samples of rats one day before the end of the experiment. Rats were divided into 4 groups: group 1 was administered regular drinking water; group 2 was administered 1% ethylene glycol in drinking water, group 3 was administered 100 mg/kg of Cannabis sativa extract for oral administration by gavage along with drinking water containing 1% ethylene glycol; and group 4 was administered 200 mg/kg of Cannabis sativa extract by gavage along with drinking water containing 1% ethylene glycol. Finally, histopathological slides from the kidney were also evaluated. Results: Results showed that 100 mg/kg and 200 mg/kg doses of Cannabis sativa extract significantly reduced the mentioned risk factors in comparison with ethylene glycol-treated rats (p<0. 05). Conclusion: Histopathological slides showed reduced calcifications with extract treatment at 200 mg/kg of Cannabis sativa. Thus, this antioxidant herb can prevent kidney stone formation. These findings pave the way for new therapy.

Isotactic polypropylene (iPP), in connection with its good processability, provides a matrix of composites applied in many industries. An influence of additives on iPP supermolecular structure, and consequently on its properties, should not be overlooked. The matter of inappropriate adhesion between a non-polar iPP matrix and polar fillers tends towards analyses and implementations of new kinds of coupling agents, e. g., polar polymeric waxes. Moreover, the presence of waxes in the composite matrix will change the MFR and may affect the iPP crystallization. To this day, literature has confirmed some beneficial effects observed during the application of polymer (e. g., polyethylene or polypropylene) waxes in the iPP composites technology, but did not demonstrate the result of its presence on iPP nucleation and crystallization. In the current paper, we focused on the simultaneous influence of lignocellulosic filler and coupling agent on crystallinity of iPP. Various research methods were applied, such as: WAXS, DSC, FTIR or PLM. Two oxidized polyethylene waxes (acid numbers: 23 and 89, respectively), as well as commercial non-oxidized polyethylene wax, were used as coupling agents. We found that an addition of 3% (by wt) of PE waxes drastically changes the processing parameters of the composites. The influence of waxes was observed in changes of crystallization kinetics, melting temperatures and in the degree of crystallinity. The percentage of crystalline phase in materials was decreased each time after waxes application. Moreover, the Shear stress applied during crystallization changed the PE waxes role on iPP crystallization in WPC composite. The beneficial effect of flowing rapeseed straw powder was decreased by the presence of PE waxes.

In this work, the numerical simulation of the non-isothermal steady co-extrusion fiber spinning with flowinduced crystallization is explored. The model is based on the formulation originally proposed by China et al. in which Newtonian and Phan-Thien-Tanner (PTT) fluids are considered the core and the skin layer, respectively. The polymeric flow rate fraction, Deborah dimensionless number and the PTTs parameters on the temperature, the velocity and the crystallization profiles are analyzed. The numerical results show: the temperature profile is sensitive to the polymeric layer flow rate and the deformation parameters (Shear thinning and extensional), the tensile stress induced crystallization parameter has a strong influence at the onset of the process, increasing drastically temperature and crystallinity.