Papers by Keyword: Coupling Agent

Abstract: In this study, waste cement is used as a filler in polypropylene (PP). Polypropylene composites with different loadings of waste cement particles (i.e.,0, 10, 20, 30, 40, and 50 phr (parts per hundred of resin)) were prepared by melt compounding with two roll mill and injection molding. Maleic anhydride grafted polypropylene (PP-g-MA) as compatibilizer and 3-aminopropyl triethoxysilane as coupling agent were selected to improve the interaction bonding between polypropylene and waste cement particles. The influence of the compatibilizer and coupling agent on the mechanical properties of PP/waste cement composites were studied. The results indicate that the incorporation of waste cement into the polypropylene matrix resulted in higher tensile modulus, flexural modulus, flexural strength, and hardness in addition to lower tensile strength, strain at break, and impact strength compared to polypropylene. The PP/waste cement composites with PP-g-MA exhibited higher flexural modulus and impact strength than PP/waste cement composites with 3-aminopropyl triethoxysilane at all waste cement loading. Nevertheless, the incorporation of 3-aminopropyl triethoxysilane improved the tensile modulus, tensile strength, flexural strength, and hardness of composites at high waste cement loading (i.e., 30-50 phr) compared to composites with PP-g-MA. Scanning electron microscope images of the fracture surfaces indicate that the addition of the compatibilizer and coupling agent in PP/waste cement composites resulted in improved adhesion between polypropylene and waste cement.

Abstract: Natural fibre matrix composites have been utilized in numerous industries, including the automotive, construction, and aerospace sectors. Maleic anhydride grafted polypropylene (MAPP) was used in this study to examine the effect of the coupling agent on the properties of a composite-produced using pineapple leaf fibre. The weight ratios of pineapple leaf fibre, polypropylene, and MAPP were 20g:180g, 15g:180g:5g, and 10g:180g:10g, respectively. The materials were mixed using a co-rotating twin-screw extruder machine at 170 °C and 50 rpm. The composite was then manufactured by injection molding at 185 °C. The mechanical and physical properties of PALF composite were examined by using a tensile test, impact test, and water absorption test. Thermal Gravimetric Analysis (TGA) was used to characterize the thermal properties of PALF/PP, and PALF/PP/MAPP composite. The surface morphology and fracture surface of the composite was characterized by using Scanning Electron Microscopy (SEM). Compared to the composite containing 5 g of MAPP, the tensile strength composite containing 10 g of MAPP produced a stronger interfacial bond. According to the impact test, adding more MAPP increases the material's strength and stress transmission. The average percentage of water absorption indicates low water absorption after the addition of the coupling agent. It can be concluded that the addition of a coupling agent improved the composite's properties.

Abstract: Banana/Coir fiber reinforced polypropylene hybrid composites was formulated by using twin screw extruder and injection molding machine. Specimens were prepared untreated and treated B/C Hybrid composites with 4% and 8% of MA-g-PP to increase its compatibility with the polypropylene matrix. Both the without MA-g-PP and with MA-g-PP B/C hybrid composites was utilized and three levels of B/C fiber loadings 15/5, 10/10 and 5/15 % were used during manufacturing of B/C reinforced polypropylene hybrid composites. In this work mechanical performance (tensile, flexural and impact strengths) of untreated and treated (coupling agent) with 4% and 8% of MA-g-PP B/C fibers reinforced polypropylene hybrid composite have been investigated. Treated with MA-g-PP B/C fibers reinforced specimens explored better mechanical properties compared to untreated B/C fibers reinforced polypropylene hybrid composites. Mechanical tests represents that tensile, flexural and impact strength increases with increase in concentration of coupling agent compared to without coupling agent MA-g-PP hybrid composites . B/C fibers reinforced polymer composites exhibited higher tensile, flexural and impact strength at 5% of Banana fiber, 15% of fiber Coir in the presence of 8% of MA-g-PP compared to 4% of MA-g-PP and untreated hybrid composites. The percentage of water absorption in the B/C fibers reinforced polypropylene hybrid composites resisted due to the presence of coupling agent MA-g-PP and thermogravimetry analysis (TGA) also has done.

Abstract: Rice-based gel is intended to be a coupling agent for usage in ultrasonic application, which made from blending of rice starch powder, sodium hydroxide, carboxymethyl cellulose, glycerin, and water. In this study we test the products for safety and efficacy in 100 patients, by four physicians. The imaging results revealed that, when compared with standard ultrasound gel, rice gel can produce equal clearness but with better echogenicity. So, rice-based ultrasound gel should be an alternative choice for general hospitals.

Abstract: The widely use of dental composite triggers a lot of research to synthesize composite made from natural sources. One of the natural sources that could be used as a filler of composite is natural zircon sand from Indonesia. The physical properties of dental composite, such as Diametral Tensile Strength (DTS) and hardness could be affected by the filler of the composite. The aim of this research is to determine the value of diametral tensile strength and hardness of prototype composite with natural zircon sand-based filler by using geopolymerization method with various coupling agents. The procedures began from synthesizing Zirconia-Alumina-Silica filler from natural zircon sand using geopolymerization method with two different coupling agents, 3-mercapto propyltrimethoxysilane (3-MPTS) and 3-aminopropyltriethoxysilane (3-APTS), which then mixed with resin matrix to form composite resin, some of the samples were then subjected to a DTS test using Lloyd Universal Testing Machine (5.6 N initial load) until a crack/fracture was formed while some of them was subjected to a hardness test using Vickers Hardness Tester. The results showed the average DTS of dental composite using MPTS coupling agent was 13.78 MPa, while the average DTS of dental composite using APTS coupling agent was 8.90 MPa, and the average hardness result of dental composite coated by 3-MPTS was higher (20.68 VHN) than composite coated by 3-APTS (18.02 VHN). This difference could be affected by filler particle composition, filler surface area and also coupling agent variation. In conclusion, the tensile strength of the prototype resin composite sample group with the natural zircon sand filler using MPTS coupling agent was higher than the APTS coupling agent group.

Abstract: Due to the excellent thermo-stability, ablation resistance and superior dielectric properties, poly-silicon-containing arylacetylene resin (PSA) shows a promising application in aerospace and spaceflight industries as a composite matrix with quartz fiber (QF). However, the non-polar nature of PSA hamper the interfacial interaction with the QF resulting in a relatively weak mechanical strength for the whole QF/PSA composites. This can be alleviated by incorporating a coupling agent between QF and PSA to reinforce their interaction. Here, new coupling agents, three ethynyl silazane derivatives, were synthesized to improve QF/PSA composite mechanical properties and named as bis (3-ethynylaniline)-diphenylsilane (SZPP), bis (3-ethynylaniline)-methylphenylsilane (SZMP) and bis (3-ethynylaniline)-phenylvinylsilane (SZPV). For SZPP, about 3.0 wt% addition of this coupling agent increased the interlaminar shear strength and flexural strength of QF/PSA composite by 21.2% and 18.4%, respectively, compared with the untreated composite. Meanwhile, among the three coupling agents, SZPV showed the best improvement in enhancing the interlaminar shear strength and flexural strength of QF/PSA composites, which reached 34.1% and 41.7%, respectively.

Abstract: The article presents the results of work on the dressing of various continuous carbon fibers of a different structure with compounds of oligomeric and polymeric nature. Using gravimetry, optical and scanning electron microscopy methods, it was shown that the fixation of sizing substances on the surface of carbon fibers depends on the brand of carbon fiber, the method of chemical activation and the nature of the sizing agent. It has been shown that the studied coupling agents exhibit increased adhesion to carbon fiber of the brand TGN-2.

Abstract: The surface state of aramid fiber was modified by coupling agent to characterize the change of the state. The fiber / epoxy resin composites were prepared to study the mechanical and electrical properties and the internal mechanism of how different surface states affect. The results show that, after the treatment with the coupling agent, the surface roughness of the aramid fiber is increased，and the content of Si on the surface reach 5.8%, thus the surface activity is enhanced. At the same time, the treatment makes the properties of composites further improved. When the filling amount of aramid fiber reaches 30 strands, the tensile strength increase by 38.4% due to the coupling agent. In the test of two-layer samples, the breakdown field strength of the composites before and after treatment with coupling agent increased by 15.9% and 20.2%, respectively.Key words: aramid fiber; coupling agent; surface state; mechanical properties; electrical properties

Abstract: Nano size of ceramic filler (nanofiller) are tend to possess difficulties to be covered by resin matrix due to large surface area to volume ratio. Addition of aceton known as the diluent agent by introducing more content of filler as well as helping distribution of the filler in the resin matrix in application of dental composite restoration. In this study, a total 24 specimens of dental composite prototype; nanofiller-TMPS and nanofiller-MPTS were prepared using a customized acrylic mold and they were divided into two groups based on filler/resin ratio (n=6 each group). In the process of dental composite making, acetone were added into resin; 1 ml (filler/resin, 50/50) and 5 ml (filler/resin, 80/20) untill specific consistency obtained. The specimens were stored in distilled water for 24 hours at 37°C then subjected to hardness test using Vickers hardness tester machine, LECO – Japan M– 400–H1 with the load of 200 grams for 15 seconds (ADA Specification No. 27). Data were statistically analyzed using t independent test (α=0.05). The result revealed that dental composite prototype contain nanofiller-MPTS with filler/resin rasio (50/50) were statistically significant higher than dental composite prototype contain nanofiller-TMPS with same ratio (p<0.05). Otherwise, dental composite prototype with filler/resin ratio (80/20) were no observed statistically significant differences for both nanofiller-TMPS and nanofiller-MPTS (p>0.05). As conclusion, nanofiller modified MPTS are more effective to elevate surface hardness of dental composite prototype than nanofiller-TMPS for 50/50 filler/resin ratio

Abstract: The different coupling agent is used for diatomite modification. The diatomite with different content are melt and mixed with polypropylene to prepare diatomite/polypropylene composites. The modification effects of different coupling agent on diatomite and the influence of agent and diatomite contents on crystallization behavior of polypropylene and mechanical properties of composites are investigated. The results show that different coupling agents have the modification effects on diatomite influence crystallization of polypropylene but the aluminum agent is better than other agents. With the increase of the content of aluminum acid ester coupling agent, the size of bubble pore is uniform, and then the compressive strength reaches to a maximum when aluminum acid ester coupling agent content is 1%. With the increase of the content of diatomite, the porosity of bubble pore of diatomite/polypropylene composite material is gradually increases. The crystallinity of polypropylene and yield strength reach to a maximum (48.15% and 21.5%) when diatomite content is 30%. In addition, the diatomite/polypropylene composites have better compressive strength than the others.