Search

The PET/PBE blends with a good balance between toughness and stiffness were prepared via a novel elongational rheology extruder. In the light of the thermodynamic factors, EGMA as an interfacial modifier was selectively localized at the interface. When the weight fraction of Ethylene/Methylacrylate/Glycidyl Methacrylate copolymer (EGMA) was 6 wt%, the impact strength of the PET/EGMA/PBE blend soared to 35.00 KJ/m2, which is nearly seven times higher than that of its un-compatibilizer counterpart. Furthermore, compared to the un-compatibilized counterpart, the tensile strength and tensile modulus of the PET/EGMA/PBE blend are only reduced by 10% and 13%, respectively. The improvement of mechanical properties of the compatibilized blends can be attributed to the enhanced interfacial reactive compatibilization between PET and PBE, and the fine dispersion of dispersed phase. The in-suit reaction between carboxyl or hydroxy group of PET and epoxy group of EGMA was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. In addition, both morphology and rheology characterization results suggested that the improved interfacial combination between PET and PBE was obtained with the inclusion of EGMA. [ABSTRACT FROM AUTHOR]

The pressure establishment in the solid conveying section of a vane extruder was theoretically and experimentally studied in the present article. Based on the structural and conveying characteristics of the vane extruder, a four-plate model was developed. The effects of the device geometry (eccentricity ζ and discharge port β), the polymer properties (different materials), and the operating conditions (temperature and rotating speed) on the pressure were also studied using a visual experimental device. The results showed that the experimental data were highly consistent with the theoretical data, which indicated that the theoretical model was sensible. Considering the optimization design of the device and its processing parameters, the eccentricity ζ and the discharge port β of the discharge baffle should be appropriately selected, and the setting temperature of the feeding section should be set to a low value. The rotating speed of the rotor had no significant influence on the pressure establishment. In addition, the thereto-mechanical history of the vane extruder was shorter than that of the conventional screw extruder. POLYM. ENG. SCI., 52:2147-2156, 2012. © 2012 Society of Plastics Engineers, INTRODUCTION Most polymer processing instruments are based on screws, such as screw extruder, screw injection molding machine, and so on. In general, screw-based plasticating and conveying extruder can be divided [...]

Sisal fibers (SFs) were pretreated by heat treatment (HT). The SFs were mixed with a biodegradable material, polylactide (PLA), and the composites were prepared by hot press molding. The effects of the HT temperature and time on the mechanical properties of the composites were investigated, and the HT mechanism was studied by scanning electron microscopy and infrared, x-ray photoelectron, and nuclear magnetic resonance spectroscopies. The results show that an appropriate HT can remove strongly hydrophilic materials such as hemicelluloses from the fibers, and thus decrease their hydrophilicity, thereby improving the retting between the fibers and the matrix. This improves fiber–matrix interfacial adhesion, which can improve the mechanical properties of the composites. The HT also influences the fiber strength to some extent and affects the mechanical properties of composites. [ABSTRACT FROM PUBLISHER]

The technology of steam explosion was adopted to modify sisal fiber (SF) material and two different carbon particles, expanded graphite and conductive carbon black (CCB), were in situ coated on the surface of SF during steam explosion process. The DC conductivity and electromagnetic interference shielding effectiveness (SE) of the modified SF/polypropylene (PP) composites were studied and the measurement of electromagnetic interference (EMI) SE was conducted in two frequency ranges of 400-1,000 MHz and 1-18 GHz. The experimental results showed that this novel coating technology could improve the SE of the modified SF/PP composites significantly, which has a strong dependence on the loadings of the expanded graphite modified sisal fiber (SF-EG) and conductive carbon black modified sisal fiber (SF-CCB). When the loadings of SF-EG and SF-CCB reached 50 wt%, the maximum values of the SE were 33 dB and 51 dB, respectively. For the modified SF/PP composites, the experimental EMI SE values are in good correlation with the theoretical calculation values in far field of electromagnetic radiation. POLYM. COMPOS., 35:1038-1043, 2014. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]