Papers by Keyword: Polymer Blend

Abstract: The blend of poly(styrene-co-acrylonitrile) (SAN) and natural rubber (NR) is immiscible and incompatible which lead to poor mechanical properties. Many methods can be carried out to improve the compatibility. In this work, the potential of various reactive compatibilizers in SAN and NR blend was explored. The morphological and mechanical properties were compared. The melt blending of SAN and NR were prepared in an internal mixer with various types of reactive agent such as styrene-co-maleic anhydride (SMA), maleic anhydride (MA), peroxide and mixed reactive agents. The morphological textures of the blends were investigated by scanning electron microscope. Mechanical properties including tensile strength, impact strength and elongation at break were measured. The results of morphological observations revealed that SAN/NR blend with reactive agent, the mixture of SMA and MA show the smallest and the most uniform dispersed NR particles, where the size of NR particle is about 1 µm. The mechanical properties of the blends revealed impact strength and elongation at break were increased with addition of reactive agents. SAN/NR blend with the mixture of SMA and MA showed the highest elongation at break but it had lower impact strength than the blend with SMA.

Abstract: Polymer blends between pristine polypropylene (PP) and post-consumer soft-drink PET bottles (rPET) were prepared using pulverization technique. The polymer mixtures were pulverized, at the amounts of rPET in PP of 0, 10, 15, 20 and 30 phr (parts per hundred of resin) by weight, into powder. In an extruder, the polymer powders were mixed with maleic anhydride-grafted polypropylene (MAPP) and polyethylene wax (PE wax) as a compatibilizer and a processing aid, respectively. The extrudates were prepared into test specimens by injection molding. Physical properties of PP/rPET blends were subsequently investigated. The results pointed out that, for the pulverized blends without compatibilizer, tensile and flexural strength were improved at the lower amount of rPET. The compatibilizing effect of MAPP was exhibited at the higher amount of rPET. The reduction of melt flow index (MFI) may cause difficulties for some processing techniques which required polymers with high MFI. The addition of PE wax successfully brought up the MFI as well as elongation at break while other mechanical properties decreased.

Abstract: Sometimes, there is a need for a material that has some properties of one polymer as well as some properties of another polymer. Instead of going back in to the laboratory and trying to synthesize a brand new polymer with all the needed

Abstract: The objective of this work was to study the production of new biodegradable thin films. As a result of increasing problems with regard to the disposal of domestic waste, particularly plastics, a new class of polymers especially designed to be biodegradable has been undergoing development. However these biodegradable plastics still have a limitation, i.e. high cost. This research studied methods of lowering the cost of biodegradable plastic and of improving its properties by using epoxidized natural rubber as a another polymer for polymer blends. Thus, ternary blends of epoxidized natural rubber (ENR), poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) were studied and prepared using a twin-screw extruder, followed by use of a chill roll cast film extruder or a blown film extruder, to produce biodegradable film. The concentration of ENR in the ternary blends was fixed at 10 wt%, with the remainder being PLA and PBAT. In some proportions of the film blends, Irganox and Uvinul were introduced to increase the thermal stabilization and UV stabilization, respectively. The mechanical and thermal properties were evaluated, including the thickness, color, and water vapor permeability (WVP) of the biodegradable films.

Abstract: A detailed experimental research on the rheological measurement by torque-rheometer (TR) based on a measuring model established by former researcher is presented. The influence of measuring conditions, material type and rotor geometric were discussed. Measuring results from the torque-rheometer were compared with those from capillary rheometer. It’s confirmed that under certain measurement conditions, torque-rheometer can accurately measure the melt rheological properties of polymer composites or blends. Measuring conditions and material type have little effect on the results accuracy. The rotor geometry has great impact on the reliability of measurement.

Abstract: Prediction of chemical shifts using quantum chemical calculation is helpful for assigning nuclear magnetic resonance (NMR) spectra, and very important in structure determination. In this paper, we calculated ¹H chemical shifts (δH) of poly (methyl methacrylate) (PMMA), poly (4-vinyl phenol) (PVPh) and their polymer blends. Density functional theory (DFT) was used to computeδH of hydroxyl groups (OH) for both PVPh homopolymer and PMMA/PVPh polymer blends. The calculated values forδH of OH groups with or without forming hydrogen bonds agreed reasonably well with the experimental values. It was found that the δH of OH groups moved downfield when they formed hydrogen bonds with both other OH groups and carbonyl groups (C=O). The simulated solid state ¹H NMR spectra based on the B3LYP // GIAO method yielded results for the PMMA, PVPh and PMMA/PVPh, showed excellent agreement with the experimental results. It indicates that the ¹H NMR spectra are influenced by the main-chain conformations and the hydrogen bond types.

Abstract: Flexible free standing polymer electrolyte films have been successfully prepared using a blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(vinyl chloride) (PVC) doped with lithium perchlorate (LiClO₄). The conductivity of the film was influenced by salt concentration and the degree of crystallinity. An optimum room temperature conductivity obtained was 2.10 x 10^-4 S cm^-1 for PVDF-HFP/PVC containing 35 wt.% LiClO₄. The temperature-dependent conductivity of the polymer films exhibited VTF-type behaviour.

Abstract: Nanocomposites are the materials that are created by introducing nanoparticulates that always referred to as filler into the matrix. Blends of polypropylene (PP)/ethylene propylene diene monomer (EPDM)/Montmorillonite (MMT) were treated by compatibilizer MAPP and irradiation of electron beam. The effects on mechanical properties for both samples were compared with the untreated nanocomposites. Because each samples used different portion of clay loading, the effects of clay loading on mechanical properties is also observed. The sample is characterized by using Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD), tensile test and impact test.

Abstract: Styrene-Butadiene-Rubber (SBR) modified bitumen had improved properties in softening points, ductility, and aging resistance. It is due to variation of molecular weight (MW) and molecular weight distribution (MWD) of the product made during the blending between SBR and bitumen. Gel permeation chromatography (GPC) analytical results indicated interaction in polymer blends that bitumen macromolecular chain biting and chemical forces as well as intermolecular recombination formed new bitumen polymer blends.

Abstract: Polymer blends of a binary system with limited miscibility are a kind of different surface structure polymer blends which main chains are same as one. The blend of polysulfone (PSf) and carboxylated polysulfone (CPSf) had been made in the solvent of dimethylacelamide (DMAc) or N-methylpyrrolidinone (NMP). The chemical polysulfones containing 0.5,1.0,1.5 and 2.0 carboxylated groups per repeat unit were mixed with Udel 300 polysulfone. The equilibrium time of two-phase polymer in solution presents their degrees of limited miscibility. The two- phase polymers could transfer as miscible blends when they had been annealed at 170 for above 6 days. Annealing of blends below the grass transition temperature(Tg) results in a decrease in enthalpy that is recovered during heating. The enthalpy recovery is visible as an endothermic peak in a differential scanning calorimeter (DSC) scan. The position of this peak depends on the composition of two-phase and on the structure of material itself. Two-sample cells were co-tested in same time for getting several Tg of limited miscible polymer blend and its component respectively. PSf/CPSf polymer blends in liquid-liquid phase separation and molecular weight distribution to be tested by High Performance Gel Permeation Chromatography (GPC). The polymer blends were showing S-O-C strength absorbance between 1000-769/cm and 3300-2500/cm to be detected by Infrared Absorption Spectrum (IR) analysis. Therefore, the reaction and enthalpy of limited miscibility between two-phase of polymer blend PSf/CPSf can be described in the paper.