Papers by Keyword: Blend

Abstract: Multifunctional heterogeneous blends offer great possibilities of tailoring properties of materials. In this work polyoxymethylene (POM) co-polymer is blended with ethylene- octene co-polymers with various alpha-octene contents (EOC38 and EOC17) in a complete volumetric content range to fabricate specific multifunctional materials with tailored stress-strain properties. Elastic properties of POM/EOC38 and POM/EOC17 binary blends are evaluated by considering Voigt, Reuss and Kerner models. It is shown that Kerner approach is more suitable for prediction of the modulus of the investigated blends in comparison to Voigt and Reuss models. It is shown that in both blends POM has a tendency to form continuous phase up to EOC contents of 0.61 and 0.78 vol. p. for POM/EOC38 and POM/EOC17 respectively. The tendency of EOC to form a matrix is not so expressed.

Abstract: Multi-component blends of polypropylene (PP), ethylene-1-octene copolymer (EOC) and zinc oxide (ZnO) are prepared by melt mixing using two-roll mill. Samples prepared by compression moulding have been investigated by using differential scanning calorimeter (DSC). It is found that addition of ZnO particles decreases PP melting point and increases crystallinity degree of PP. ZnO works as nucleation agent for PP by increasing quantity of crystallization centers, but at the same time decreasing structure quality. Because of the structure change mechanical properties are affected. At lower nanoparticle concentration some reinforcement effect I observed, while at higher particles concentration brittlening occurs. Crystalline structure and particles nature increases thermal stability of PP and PP/EOC blends.

Abstract: Shenfu coal (SFC) was pulverized and modified with planetary ball mill. Maceral separation of the coal was performed by means of density gradient centrifuge in zinc chloride solution. Blends from low density polyethylene (LDPE) and parent coal powder, iron ions loaded coal powder, or floated maceral fractions were prepared in co-rotation twin-screw extruder. Pyrolysis characteristics were investigated based on differential scanning calorimetry (DSC) measurements, apparent activation energies were calculated according to Kissiger and Ozawa methods. It is found that chemical interaction between SFC and LDPE is attributed to their overlapped pyrolysis temperature regions, leading to instant and rapid propagation and termination of macromolecular chains produced in the co-pyrolysis. Iron ions loaded in the coal can facilitate formation of radicals with acceleration in chemical reaction rates. Thermal degradation of LDPE is rate-determining step in co-pyrolysis of the coal and the polyethylene. Maceral fraction floated in 1.25g·cm^-3 zinc chloride solution is more reactive with polyethylene due to its higher content in aliphatic hydrocarbon and hydrogen, playing a role of excellent hydrogen donor to LDPE in the co-pyrolysis.

Abstract: The blends of recycled poly (ethylene terephthalate) (r-PET)/thermoplastic polyester-ether elastomer (TPEE)/acrylic acid grafted low density polyethylene (LDPE-g-AA) were prepared by extrusion and injection molding. The mechanical, morphological and rheological properties of the blends were investigated by mechanical test, SEM and torque rheometer, respectively. The results show that the Charpy impact strength of the blends increases to the maximum when adding 3 wt % LDPE-g-AA and then decreases with the further increase of LDPE-g-AA contents, while the tensile strength of the blends decreases with the increase of LDPE-g-AA contents. The SEM shows that the particle sizes of TPEE in the blend containing 3wt% LDPE-g-AA become much smaller than that in the uncompatibilized blends, and a more uniform and better islands-in-sea morphology is obtained. Furthermore, the addition of LDPE-g-AA decreases the viscosity of the blends, leading to an overall improvement of processability. From these results above, it can be concluded that the introduction of LDPE-g-AA increases the compatibility and processability of r-PET/TPEE blends effectively.

Abstract: Natural rubber (NR) latex is widely used in the manufacture of thin film barrier products such as gloves and condom. However, due to its low T_g, film casted from NR latex is soft and tacky, and needed to be strengthened to produced high performance products. Films of prevulcanized natural rubber latex (PVNR) blended with nanosized copolymer of n-butyl acrylate/butyl methacrylate (BA/BMA) were prepared at three different ratios of acrylate copolymer: PVNR. The tensile strength and elongation at break of films prepared decreased with increasing ratios of acrylate copolymer:PVNR. FESEM images showed the occurrence of agglomeration of the acrylate copolymers with PVNR molecules. The degree of agglomeration of the blended molecules increased with percentages of copolymer added. The decrease in the tensile strength and elongation at break may due to the agglomeration of the blended molecules suggesting poor dispersion and/or destabilization of PVNR molecules.

Abstract: The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) at four different blends ratios were prepared via melt blending, with addition of liquid natural rubber (LNR) as compatibilizer. The effect of blend ratio and temperature on the tensile properties and swelling ratio was studied. The addition of NR and LNR into TPU produces a decrease of tensile strength. The swelling ratio increased with the increasing of NR content in the blends. The temperatures of blending also give effects to tensile properties and swelling behavior.

Abstract: This paper studies the properties of the blends composed of DCLR (direct coal liquefaction residue) and asphalt using two different processing methods, compares the regulation that the DCLR additive content and processing method take influence on the high-temperature properties, low-temperature properties and durability of the blends. It is found that the DCLR can improve the high-temperature properties of asphalt but degrade its low-temperature properties. The properties of blends composed of DCLR, asphalt and furfural extract oil are tested and analyzed by adding a certain amount of furfural extract oil into it, which shows that adding DCLR can improve the high-temperature properties of asphalt and reduce its low-temperature properties but can hardly cause any impact on the properties of the blends. In addition, the processing method has a direct influence on the properties of blends.

Abstract: The present study reports obtaining biofuel by pyrolysis of plant oil and animal fat. This process consists in breaking of molecules at high temperatures, obtaining hydrocarbons, similar to oil, and oxygenates such as esters, carboxylic acids, aldehydes, etc. The research aimed to evaluate the thermal and kinetic behaviour and the heat of combustion of bio-oil and bio-oil mixtures / diesel oil. In this work, Thermogravimetric studies were performed (TG) at a heating rate of 10 ° C min^-1 under air atmosphere synthetic, Thermodynamic studies (ΔH, ΔS and ΔG) and about heat of combustion also were done. Thermal stability at 30°C was observed from thermogravimetric study. The kinetic calculations were performed in order to observe parameters such as activation energy (Ea) and Arrhenius factor.

Abstract: Polymer blending provides an efficient way to develop new materials with improved properties while preserve the primary properties of the materials at lower cost. The blends recycled high density polyethylene (rHDPE) and recycled polypropylene (rPP) with and without maleic anhydride polypropylene (MAPP) have been investigated. The effect of different blend ratios on tensile properties, morphology and melt flow index were studied. The tensile strength and modulus of elasticity of both blends increased with increased of rPP in the blend ratios but the elongation at break decreased. It was found that the tensile strength and modulus of elasticity of compatibilized rHDPE/rPP blends higher than uncompatibilized blends. The SEM micrograph of tensile fractured surface of compatibilized blends showed better interfacial adhesion and interaction between rHDPE and rPP. The melt flow index of compatibilized blends showed better flowablity than uncompatibilized blends.

Abstract: Thermoplastic elastomers (TPEs) based on dynamically cured epoxidized natural rubber/copolyamide (ENR/COPA) blends were prepared. Influence of curing systems (i.e., sulphur, peroxide, mixed sulphur and peroxide and phenolic resin cured systems on mechanical, dynamic and morphological properties of the blends were investigated. It was found that the blend with phenolic cured system exhibited superior mechanical and set properties. That is higher tendency to recover to its original shape after a prolong extension. It was also found that the blend with peroxide cured system exhibited higher storage modulus and complex viscosity than those of the blends with mixed sulphur and peroxide, phenolic and sulphur cured system, respectively. Furthermore, the TPVs blend with peroxide cured system showed the smallest vulcanized rubber particles.