In this work, the polytetrafluoroethylene (PTFE)-based composite substrates were manufactured by mixing, calendering, hot-pressing sintering. The composition of all the samples was PTFE, SiO2 and chopped E-glass fiber...In this work, the polytetrafluoroethylene (PTFE)-based composite substrates were manufactured by mixing, calendering, hot-pressing sintering. The composition of all the samples was PTFE, SiO2 and chopped E-glass fibers. The effects of content of E-glass fibers on the properties of the SiO2 filled PTFE composites were investigated, including density, water absorption, dielectric properties (εr, tanδ), coefficient of thermal expansion (CTE) and temperature coefficient of dielectric constant (τε). The compositions of inorganic materials mixture are (62 ? x) % SiO2 + x % E-glass fiber (x: mass ratio to composites, x = 0, 1, 1.5, 2, 2.5, 3). The results show that as the content of E-glass fibers is 2.5 wt.%, this composite obtains optimal properties, including excellent dielectric properties (εr^2.9123, tanδ~0.0011), acceptable water absorption of 0.075%, temperature coefficient of dielectric constant of 10 ppm/?C and coefficient of thermal expansion of 15.87 ppm/?C.展开更多
Short jute fiber (2 - 3 mm) reinforced polypropylene PP-based composites (20% fiber by weight) were fabricated using compression molding and the mechanical properties were evaluated. Tensile strength (TS), tensile mod...Short jute fiber (2 - 3 mm) reinforced polypropylene PP-based composites (20% fiber by weight) were fabricated using compression molding and the mechanical properties were evaluated. Tensile strength (TS), tensile modulus (TM), elongation at break (Eb%), flexural strength (FS), flexural modulus (FM), impact strength (IS), and hardness of the composites were found to be 32 MPa, 850 MPa, 12%, 38 MPa, 1685 MPa, 18 kJ/m2 and 96 shore-A, respectively. Then short E-glass fiber (2 - 3 mm) reinforced PP-based composites (20% fiber by weight) were fabricated and mechanical properties were compared with short jute-based composites. Short jute-based composites showed excellent mechanical properties and comparable to short E-glass-based composites. Soil degradation test of both types of composites indi-cated that jute/PP composites significantly lost much of its mechanical properties but E-glass/PP composites retained major portion of its original integrity. Interfaces of the degraded composites were investigated by scanning electron microscopy and supported the biodegradation properties of jute/PP composites.展开更多
Mechanical properties of ukam, banana, sisal, coconut, hemp and e-glass fibre reinforced laminates were evaluated to assess the possibility of using it as new material in engineering applications. Samples were fabrica...Mechanical properties of ukam, banana, sisal, coconut, hemp and e-glass fibre reinforced laminates were evaluated to assess the possibility of using it as new material in engineering applications. Samples were fabricated by the hand lay-up process (30:70 fibre and matrix ratio by weight) and the properties evaluated using the INSTRON material testing system. The mechanical properties were tested and showed that glass laminate has the maximum tensile strength of 63 MPa, bending strength of 0.5 MPa, compressive strength of 37.75 MPa and the impact strength of 17.82 J/m2. The ukam plant fibre laminate has the maximum tensile strength of 16.25 MPa and the impact strength of 9.8J/m among the natural fibres;the sisal laminate has the maximum compressive strength of 42 MPa and maximum bending strength of 0.0036 MPa among the natural fibres. Results indicated that natural fibres are of interest for low-cost engineering applications and can compete with artificial glass fibres (E-glass fibre) when a high stiffness per unit weight is desirable. Results also indicated that future research towards significant improvements in tensile and impact strength of these types of composites should focus on the optimisation of fibre strength rather than interfacial bond strength.展开更多
文摘In this work, the polytetrafluoroethylene (PTFE)-based composite substrates were manufactured by mixing, calendering, hot-pressing sintering. The composition of all the samples was PTFE, SiO2 and chopped E-glass fibers. The effects of content of E-glass fibers on the properties of the SiO2 filled PTFE composites were investigated, including density, water absorption, dielectric properties (εr, tanδ), coefficient of thermal expansion (CTE) and temperature coefficient of dielectric constant (τε). The compositions of inorganic materials mixture are (62 ? x) % SiO2 + x % E-glass fiber (x: mass ratio to composites, x = 0, 1, 1.5, 2, 2.5, 3). The results show that as the content of E-glass fibers is 2.5 wt.%, this composite obtains optimal properties, including excellent dielectric properties (εr^2.9123, tanδ~0.0011), acceptable water absorption of 0.075%, temperature coefficient of dielectric constant of 10 ppm/?C and coefficient of thermal expansion of 15.87 ppm/?C.
文摘Short jute fiber (2 - 3 mm) reinforced polypropylene PP-based composites (20% fiber by weight) were fabricated using compression molding and the mechanical properties were evaluated. Tensile strength (TS), tensile modulus (TM), elongation at break (Eb%), flexural strength (FS), flexural modulus (FM), impact strength (IS), and hardness of the composites were found to be 32 MPa, 850 MPa, 12%, 38 MPa, 1685 MPa, 18 kJ/m2 and 96 shore-A, respectively. Then short E-glass fiber (2 - 3 mm) reinforced PP-based composites (20% fiber by weight) were fabricated and mechanical properties were compared with short jute-based composites. Short jute-based composites showed excellent mechanical properties and comparable to short E-glass-based composites. Soil degradation test of both types of composites indi-cated that jute/PP composites significantly lost much of its mechanical properties but E-glass/PP composites retained major portion of its original integrity. Interfaces of the degraded composites were investigated by scanning electron microscopy and supported the biodegradation properties of jute/PP composites.
文摘Mechanical properties of ukam, banana, sisal, coconut, hemp and e-glass fibre reinforced laminates were evaluated to assess the possibility of using it as new material in engineering applications. Samples were fabricated by the hand lay-up process (30:70 fibre and matrix ratio by weight) and the properties evaluated using the INSTRON material testing system. The mechanical properties were tested and showed that glass laminate has the maximum tensile strength of 63 MPa, bending strength of 0.5 MPa, compressive strength of 37.75 MPa and the impact strength of 17.82 J/m2. The ukam plant fibre laminate has the maximum tensile strength of 16.25 MPa and the impact strength of 9.8J/m among the natural fibres;the sisal laminate has the maximum compressive strength of 42 MPa and maximum bending strength of 0.0036 MPa among the natural fibres. Results indicated that natural fibres are of interest for low-cost engineering applications and can compete with artificial glass fibres (E-glass fibre) when a high stiffness per unit weight is desirable. Results also indicated that future research towards significant improvements in tensile and impact strength of these types of composites should focus on the optimisation of fibre strength rather than interfacial bond strength.
