Advanced Materials Research Vols. 87-88

Abstract: To ensure good compatibility between polymer and montmorillonite (MMT), three types organophilic-MMT were prepared and the influence of modifying agent style on the modification effect was studied. The results of X-ray diffraction(XRD) show that the modified reagents are all intercalated into the galleries of MMT, which are also proved by patterns of FT-IR and thermogravimetric analysis(TGA), and the spacing of MMT layers increases from 1.23 nm of the pristine MMT to 2.10nm, 3.52nm and 4.14nm for CTAB, SDS and DBS modified MMT respectively. The results also indicate that the d-spacing and exfoliation degree of anionic surfactants inserted MMT is bigger than that of the cationic surfactants treated MMT, which are usually used to preparation polymer layered silicate nanocomposites in literatures. So PS/SDS-MMT and PS/DBS-MMT nanocomposites were prepared by suspension polymerization. The structure of complex were characterized by XRD and no peak can be observed by the spectra, which suggest that the clay platelets have been exfoliated and dispersed in the PS matrix and the both complex are all have exfoliated structure. FT-IR spectrums analysis confirmed the existence of MMT which implied that the layers of silicate was distributing in composites. The results of TGA show that nanocomposites possess exceptionally high thermal stability and the DBS treated composite has higher thermal stability than that of SDS treated.

Abstract: The study was based on researching various parameter of vulcanization shaping process for effect of radial force variation (RFV).The experimental results showed that reducing the first and second shaping pressure, and increasing hole diameter of N2 on curing bladder, and extending times of discharged N2 in shaping process, and reducing pressure of expanded bladder at the moment of closing mold, could reduce RFV of TBR tire and improve uniformity of tire and provide base data of product process.

Abstract: The forecast of rubber's plasticization technological parameter computation model is established using the neural network method on open mill. It is computation that rubber's plasticization technological parameter on open mill by this model, and has carried on the comparison the result with the experimental one. The result indicated that this model precision is high, and it has the good project application value in the research aspect of rubber's plasticization technological parameter on open mill.

Abstract: Hydrogels donate moisture to dehydrated tissue and absorb some moisture and accepted in wound healing. Polypropylene (PP) SMS nonwovens were grafted polyacrylic acid (PAA) hydrogel technique contanining chitosan to enhance hydrophilicity and antibacterial activity. In the first stage, nonwovens were hydroxylated by treatment with aqueous potassium peroxydisulfate solution under a strong flow of nitrogen. In the second stage, the hydroxylated nonwovens were subjected to grafting of acrylic acid using cerric ammonium nitrate as an initiator. Subsequently, chitosan was grafted onto the modified NWs with N,N'-Methylenebisacrylamide. The modified nonwovens were characterized by XPS spectroscopy and SEM, the results showed that acrylic acid was copolymerized and hydrogel grafted onto SMS nonwovens. Hydrogel grafted nonwovens exhibited enhanced wettability and water absorption ability. With introduce of chitosan further, the modified NWs exhibited effectively antibacterial activity against E.coli.

Abstract: Based on the Adina finite element analysis software, 3D axisymmetric finite element analysis model of the 205/75R15 PCR tire was established, the steady temperature field of rolling tire was simulated, and the thermal distribution colored cloud diagram of steady-state temperature field of 3D rolling tire which directly shows the temperature distribution of each section of tire was analyzed to offer certain guidance to the improvement of tire structure and rubber formula.

Abstract: The paper proposes that cold insulation property is improved by adding additives and adopting different polymer materials and shows polymer material broad prospects in cold insulation structures. The paper has certain reference value to polymer material performance research.

Abstract: Based on vortex-velocity method, the control equations of laminar flow of high vicious fluid in a square cavity driven by the continuous periodic vibration motion of upper and bottom lids are derived. And then the numerical solution of the transient velocity field which is based on the superposition method is obtained by using the finite volume method. The motion of the passive tracer is numerically integrated by the fourth order adaptive Runge-Kutta scheme. The results show that when the frequency is below 0.1Hz, the mixing is controlled by the globally chaotic mixing. While the frequency increases to between 0.1 Hz and 0.5 Hz, the quasi-periodic islands occur in the region of chaotic motion. After the frequency exceeds 0.5Hz, the mixing degenerates into the regular laminar mixing. Through the contrasts of Poincaré sections, it is proved that the frequency not only has the effect on the scales of KAM islands, but also dominates the mixing transition from the globally chaotic mixing to the traditionally regular laminar mixing.

Abstract: Five kinds of carbon black filled natural rubber were prepared, and thermal conductivity was studied considering two factors, which include temperature and volume percent of the filler. It was found that thermal conductivity had relevance to temperature and volume percent of carbon black, besides, structure and specific area of carbon black were also very important influencing factors. Moreover, reuniting phenomenon of nanometer grade of carbon black has much effect on thermal conductivity.

Abstract: Melt flow properties in micro cavity play an important role in the micro injection molding (MIM). Based on the point view of improving the melting plastification quality, this study focus on solving the problem of melt filling difficulty in micro cavity of MIM by introducing the ultrasonic vibration field into the polymer plastification process. This paper studied the polymer’s ultrasonic plasitfication process by Theoretical analysis and Polymer ultrasonic plastification experiment.

Abstract: Filling imbalance for PP, long GF-PP, elastomer PC and GF-PC in a multi-cavity mold with a geometrically balanced runner is investigated by using the visualization glass-inserted injection mold and infrared thermometers, through visualizing the flow behavior of the melt in the runner and cavity and measuring the melt temperature near the cavity entrance simultaneously. In addition, velocity distribution in the secondary runner for PP and elastomer is also determined by use of marker tracers in order to further investigate the mechanism of filling balance. The results show that the degree of filling imbalance depends on the velocity difference of the upper and lower melt and its development in the secondary runner during the filling process. The melt viscosity difference in the primary runner dominate the melt velocity difference in the secondary runner., and the viscosity difference depends on the temperature difference and viscosity sensitivity to temperature and shear rate. The development of the velocity difference of the upper and lower melt in the secondary runner depends on the melt viscoelastic property and the runner wall condition.