Advanced Materials Research Vol. 893

Abstract: Glycidyl methacrylate (GMA) grafted acrylonitrile-butadiene-styrene (ABS) in the presence of styrene (St) monomer (AGS) was used as a compatibilizer in the immiscible poly(butylene terephthalate)/poly(acrylonitrile-styrene-acrylate) (PBT/ASA) blends. SEM analyses display a better dispersion of ASA particles in the PBT matrix with the content of AGS less than 4.0 wt% compared with the PBT/ASA blends. Rheological measurements show that the melt elasticity and melt strength of blends increase with increasing ABS-g-(GMA-co-St) content. The behavior of blends shifts from “liquid-like” to “solid-like” and the relaxation time moves to higher values by introducing AGS. 3.0 wt% AGS is the optimum concentration for PBT/ASA system.

Abstract: Polypropylene-based composites are prepared using hydrolyzed collagen (HC) from wastes of the leather industry. Blends of polypropylene and HC were studied as a function of the blend composition ratio with the aim of developing a formulation with optimal physical-chemical and mechanical properties. The prepared mixtures were characterized by thermal analyses and mechanical test. Blends with content up to of 20-30% of collagen hydrolizate are susceptible to be melt processed to provide transparent, cohesive and flexible films. In front of positive results the reutilization of collagen hydrolizate derived from the tannery industry appears feasible for production of thermoplastic items for applications in packaging and agricultural segments.

Abstract: The acidified multi-walled carbon nanotubes (MWNTs-COOH) was obtained by nitric acid treatment on multi-walled carbon nanotubes (MWNTs).The PI/MWNTs-COOH composite films were synthesized by in situ polymerization. The thermal stability, resistance and mechanical properties of PI/MWNTs-COOH composite were evaluated. The results showed that: the composites maintained a good thermal stability with the addition of the MWNTs-COOH; the resistance of the composite film dropped at first, and rose up later. While the tensile strength increased at first and then decreased. In conclusion, the PI/MWNTs-COOH composite films exhibited better thermal, antistatic and mechanical properties compared with neat PI.

Abstract: The dynamic characteristics of fiber reinforced polymer skins with the alternate arrangement of continuous and chopped fibers on the polypropylene honeycomb core are investigated. It is envisaged that the damping could be improved by splitting the length of fiber into different short lengths so that more energy can be dissipated. The dynamic characteristics of FRP specimens with different forms of fibers were studied. The fibers were considered in the following five groups:, all continuous fibers, alternate arrangement of continuous and two chopped fibers, the same with three chopped fibers, four chopped fibers, and the five chopped fibers in. The natural frequencies and damping loss factors were evaluated by using the impulse technique with the half power band width method. The results revealed that for a given fiber volume fraction the damping could be improved by reducing the length of fibers.

Abstract: The study investigates the effects of various contents of rice husk silica (RHS) on mechanical properties of polysiloxane (POS) sheet composite. The polysiloxane sheet composites filled with 5wt%, 10wt%, 15wt% and 20wt% of RHS were fabricated using casting technique at room temperature. The polysiloxane sheet reinforced RHS (POS-RHS) composites were characterised using thermogravimetry analysis (TGA), Fourier Transformation Infrared Spectroscopy (FTIR) and tensile test to determine the thermal and mechanical properties. It was found that the RHS as filler in polysiloxane is improvement in mechanical properties and the curve degradation of POS and POS-RHS are similarly. By using FTIR was shown the affect of Si and O bonding from RHS as filler.

Abstract: Glycidyl methacrylate (GMA) grafted ethyleneoctene multi-block copolymer (OBC) in the presence of the styrene (St) monomer (OBC-g-(GMA-co-St)) was prepared and then used as a compatibilizer for recycled Poly (ethylene terephthalate)/Polypropylene (R-PET/PP) blends. The morphological, rheological and mechanical properties of the blends were investigated. The results show that the compatibilization between R-PET and PP blends is improved by the introduction of OBC-g-(GMA-co-St). The SEM results show that all R-PET/PP blends exhibit a matrix-dispersed droplet type morphology, and the addition of OBC-g-(GMA-co-St) results in a finer morphology and better adhension between the phases. In addition, the storage moduli (G'), loss moduli (G") and the Charpy impact strength of the blends increase with increasing OBC-g-(GMA-co-St) content, while the the flexural strength decreases slightly.

Abstract: Boron nitride (BN) powder was modified by silane coupling agent, and a series of cyanate ester resin composites containing the modified BN were prepared. The effect of volume fraction of BN on the thermal conductivity, electrical insulation properties of these composites was investigated. Results show that addition of a little of BN powder can improve thermal conductivity of the composites effectively, while the composites still retain the relatively good electrical insulation and low dielectric constant. When the volume fraction of BN was 23.6%, the thermal conductivity of composite increased to 1.33 W/(m·K), which is 4.6 times that of pure resin.

Abstract: The tribological behavior of C/C composite with smooth lamination (SL) and rough lamination/resin carbon (RL/RC) matrixes was tested using M2000 wear tester and the worn surface morphology was investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Lateral Force Microscopy (LFM) methods. It is found that the worn surface of SL exhibits rough friction film and large worn particles with diameters about 300 nm and with leaning-angles around 30 °. Comparatively, the worn surface of RL/RC achieves smooth friction film and is full of small particles with the grain size about 100 nm and with leaning-angles about 10 °. It is demonstrated that RL/RC exhibits a high density of 1.86 g/cm³, high graphitization degree of 67 %, and extensively low hardness of HRF 42. Those superior properties contribute to the close friction force of different components and excellent tribological behavior.

Abstract: We study systematically the morphology and graphitization of the worn surface of C/C composite with rough lamination/smooth lamination/resin carbon (RL/SL/RC) as matrix precursor tested by using M2000 wear tester with a couple of Cr-coated 40 Cr steel. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses indicate that the worn surface of RL/SL/RC is integrated. Particles with the size of 100~300 nm could be found on the worn surface. The leaning-angles of the particles against the sliding direction on the worn surface are between 30 ° and 50 °. Raman laser spectrum (RLS) analysis reveals that, after the wear test, the graphitization on the worn surface of RL/SL/RC decreased with the increase in load, but graphitization of the fiber kept constant and that of the boundary increased up to 150 N. The surface graphitization of different components became closer and closer with the increase in load.

Abstract: The interest in natural fibers has been rising in the past decade due to low cost and abundant availability. Though the composites made from artificial fibers possess superior properties when compared to natural fiber reinforced composites, their high cost makes it unviable in day-to-day applications. This paper is an evaluation of a pineapple fiber reinforced composite using epoxy resin as matrix. Glass fibers are provided as the outer layers to improve the surface finish and strength. Using hand lay-up method, fibers of pineapple are assembled in alternate layers of vertical and horizontal orientation. The flexural properties of the composite are determined. Three samples are tested and it is seen that there is no appreciable variation in the properties. The average break load is 1.29 KN and the deflection is 5.533 mm. The flexural strength is calculated as 78.63MPa.