Summary The chlorination of tung oil was investigated, and certain chlorinated products were screened as plasticizers for polyvinyl
chloride resin. Chlorine readily added at low temperatures (0 to 20°C.) as well as at higher temperature (75°C.). The chlorination
was highly selective for triene conjugation as the disappearance of triene closely paralleled the amount of chlorine added
during early staged to chlorination. Considerable conjugated diene is formed as indicated by characteristic ultraviolet absorption
in the diene region. In later stages of chlorination considerable substitution occurs as evidenced by the fact that products
containing more than 40% of chlorine could readily be obtained. All the products were more or less unstable, evolving hydrogen
chloride and darkening at room temperature. The chlorinated tung oils were screened as plasticizers, at the 30% level, for
polyvinyl chloride by using butyl epoxystearate as a stabilizer. Products containing small proportions of chlorine (less than
about 20%) were not compatible with polyvinyl chloride; products containing moderate amounts (about 30%) were compatible and
had some plasticizing effect but decomposed excessively on milling. Those products containing the highest proportion of chlorine
(more than 40%) were compatible and did not decompose on milling or molding. These highly chlronated tung oilslowered the
milling temperature of polyvinyl chloride copolymer but showed little, if any, ability to product compositions which are flexible
at room temperature.
Presented at the 32nd Annual Fall Meeting, American Oil Chemists' Society, Chicago, Ill., October 20–22, 1958.
One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S.
Department of Agriculture. 相似文献
The dielectric, mechanical and thermal properties were investigated for poly(2,6-dichloro-1,4-phenylene oxide) (PDCPO), poly(2-chloro-6-methyl-1,4-phenylene oxide) (PCMPO) and poly(2,6-dimethyl-1,4-phenylene oxide) (PDMPO). PDCPO exhibited two dielectric secondary relaxations designated as β and γ processes around 160 and 100K, respectively. The γ process was assigned to the motion of a trace of chloroform included in the PDCPO film. A blend film PDMPO/PCMPO ( mixing ratio) exhibited dielectric relaxation around 330K and the process was assigned to the rotation of phenyl group with respect to oxygen-phenyl-oxygen axis. No dielectric relaxation was observed for the PDMPO film dried carefully, while the PDMPO film kept under an atmosphere of water vapour exhibited dielectric relaxation due to the motion of the water molecules at about 180K. Tensile stress at break measured on PDCPO prepared by Stamatoff's method was 38 MPa and was much higher than that for PDCPO prepared by the method reported by Blanchard et al. Temperature dependence of the dynamic Young's modulus for PDCPO measured at 110 Hz exhibited no appreciable loss peak in the range below 480K. Glass transition temperatures for PDCPO, PCMPO and PDMPO were determined to be 490, 445 and 500K, respectively, by differential scanning calorimetry. 相似文献
Nanocomposites made of poly(ethylene terephthalate) (PET) and graphene nanoplatelets (GNPs) were fabricated through micro-compounding and micro-injection molding. With an objective of improving the interactions between GNP sheets and PET chains, PET pellets were ground into a fine powder. PET pellets and powders were mixed with GNPs at 2%, 5%, 7.5%, and 10% (wt.%), molded to fabricate the nanocomposites, and then tested using several analytical characterization tools. Mechanical testing showed greater improvement through powder mixing, resulting in a 58% increase in the elastic modulus of the nanocomposites at 10% weight fraction. Thermal behavior of the nanocomposites was evaluated through differential scanning calorimetry (DSC), and it was observed that addition of GNPs into PET powders at 10% increased the crystallinity of the PET 50%. Confocal microscopy confirmed that mixing GNP with PET powders results in a more uniform distribution of the GNPs in the matrix compared to the mixture with PET pellets. X-ray diffraction (XRD) analysis confirmed the presence of GNPs with preferred orientation within the PET matrix.
In this study, the reinforcement effects of low-content hydrophilic nanodiamond (ND) on linear low-density polyethylene (PE) nanocomposites were investigated. ND was incorporated in PE via simple solution blending. The obtained PE/ND nanocomposites were characterized using scanning electron microscopy, ultraviolet–visible spectra, X-ray diffraction, tensile test, thermogravimetry, and differential scanning calorimetry. Generally, PE/ND nanocomposites with poor interfacial interaction cause large agglomerates, resulting in brittle and poor mechanical properties. Owing to the different natures of non-polar PE and polar ND, the higher the ND content, the larger the agglomerates formed in the nanocomposites. However, PE/ND nanocomposites show unique mechanical properties, that is, the Young's modulus, tensile strength, elongation at break, and toughness increased upon the incorporation of ND. The Young's modulus of the PE/ND nanocomposites exceeded the theoretical value calculated using the Halpin–Tsai model. In addition, the toughness increased by 18% at only 0.5 wt% ND loading. Furthermore, there was an increase in the thermal degradation temperature, melting temperature, and crystallization temperature. 相似文献
Dynamic mechanical properties of biphasic PVC/CPE polymer blends of different micromorphology were studied. It was revealed that a considerable interaction existed between the polymers involved in the high-impact polymer blends. It was established that the most favorable cold impact strength of the high-impact PVC/CPE alloy was obtained when a structure of mixed morphology had been formed in the course of processing. As indicated by the DMA spectra, more marked plasticizing effect of CPE appeared at a lower thickness of CPE layer among the primary globules, i.e., at a higher extent of wetting the PVC globules by CPE molecules. This phenomenon is manifested by splitting the β-relaxation transition of PVC. 相似文献
The aim of this work is to obtain and evaluate the mechanical and thermal properties of low Density Polyethylene (LDPE) composites reinforced with fibers from Australian King Palm fibers. Raw fibers were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) Spectroscopy. The chemical composition of the fibers was also evaluated. After characterizing the fibers were mixed into the LDPE, in proportions of 5, 10, 15 and 20% (wt/wt) using a thermokinetic mixer model MH-50H. Furthermore tensile, flexural and impact specimens were prepared for evaluation of mechanical properties. The composites were analyzed through SEM micrographs of fractured surfaces and thermal analysis. The results indicate that the reinforcement decreases the thermal stability of the composites, but caused an increase the mechanical properties of the composites. The composites reinforced with of raw fibers 20% (wt/wt) showed significant increase in the tensile strength, flexural and impact. 相似文献