Advanced Materials Research Vols. 399-401

Abstract: The tensile strength of carbon fiber reinforced resin matrix layer splice laminate was studied. Three specimens (M1.M2.M3) were cut from laminates with different joint location and the number of layer splice. Load schemes were performed and typical load-displacement curves of three specimens were recorded. The result shows that the joint location has seriously effect on the tensile strength and modulus of specimens. The tensile strength of M2 is obviously lower than that of M1 and M3. Furthermore finite element ABAQUS6.5 was also used to simulate the course of experimental test. The result shows that shear stress concentration occurs on the joint of model. The shear stress on the model M1 and M2 has the similar trend and concentrates in the middle of the joint area. And on the model of M3 the shear stress has a completely different trend from the M1 and M2 model. On the M2 the shear stress concentration is slightly higher than the other two. It indicates that the tensile strength of M2 is the lowest among the three models. So, the inter-laminar shear stress is the major factor leading tensile failure. The experimental tests are consistent with the finite element analysis.

Abstract: Thin-layer molecularly imprinted composite membranes for selective binding and permeation of levodropopizine were developed via thermal-initiated surface modification of polyvinylidene fluoride microfiltration membranes. ATR-FTIR was used to analyze the surface structures of these membranes. Binding experiments revealed that the saturated binding capacity of MICM was 75.746 umol /g, nearly 3 times higher than that of NICM. Scatchard analysis showed that binding specificity of MICM was a result of multi-site binding to the template. The selective factor of LDPZ and 1-phenylpiperazine was 2.344 in competitive permeation studies. The permeation mechanism of LDPZ imprinted membranes could be inferred as facilitated permeation mechanism.

Abstract: Thermo-sensitive polyurethane (TSPU) was synthesized from poly(ε-caprolactone) and 4,4’-methylenebis (phenyl isocyanate) by a two-step process with 1,4-butanediol as the chain extender. Following that, a novel temperature-sensitive material was created by the strategy of IPN from TSPU and PNIPAAm in the method of in situ polymerization. The chemical structure and thermo properties of the semi-IPN were characterized with FT-IR and DSC. The results prove that intensive inter-molecular interactions exist between TSPU and PNIPAAm chains, which have significant influence on the phase transition behaviors of the material. According to these results, the transition temperature of the semi-IPN can be adjusted in the range of 30~40 °C by controlling the composition of TSPU and the semi-IPNs.

Abstract: Before chemical vapor deposition, PAN-based carbon fibers were modified by anodic surface treatment for different time, using 5% ammonium bicarbonate as electrolyte. Effects of the surface treatment on surface mophology, chemical functional groups of carbon fibers were investigated. The microstructure of pyrocarbon were analysed as well. The results show that the anodic surface treatment by 5% ammonium bicarbonate for proper time can improve the surface morphology and adjust the surface functinal groups of carbon fibers, which can promote the deposition of ordered pyrocarbon during chemical vapor deposition.

Abstract: This paper is to research the manufacturing process of A356 alloy matrix composites reinforced by SiC particles by mechanical stirring and how the size of particles ,volume fraction affect mechanical property has been studied , too. The text results revealed that larger particles especially particle size larger than 30um were suitable using this technique, meanwhile, it will hard to adding particles into the alloy when particle lower than 20um size. The effects of SiC particle addition on the hardness properties of A356 alloy and with higher volume fraction particles lead to greater hardness.

Abstract: Flat crush performance test, edgewise compressive properties test and sheering properties test of both ripple structure and latticed structure sandwich composites were performed respectively. Test value of elastic modulus was obtained. Contrastive analyzing the test value and calculated value, the correctness and feasibility of equivalent mechanical model were testified.

Abstract: CNTs-TiAl/B₄C composite has been obtained by high energy ball milling and hot press sintering. These technical process promoted the solid reaction and resulted in the formation of composites comprising Ti-Al, TiC, TiB₂ and B₄C. The SEM images and measurement of the mechanical properties proved that the addition of 1.5wt.% CNTs further improves the fracture toughness and the bending strength of TiAl/B₄C composites.

Abstract: The biodegradable composite films were prepared from bagasse microcrystalline cellulose as filler and poly(vinyl alcohol)(PVA) as polymeric matrix. The crystallinity, the tensile properties and the thermal properties of the composites were tested. Bagasse microcrystalline cellulose was distributed in PVA films as the crystalline state. The results show that the tensile properties and thermal properties were improved with the addition of bagasse microcrystalline cellulose. When bagasse microcrystalline cellulose mass fraction was 5%, both temperature of initial decomposition and maximum weight loss rate of composite film were raised by 11.71°C and 36.86°C, and the tensile strength increased by 17.88%, and the elongation at break increased by 36.62% compared to those of pure PVA.

Abstract: The rubber powder, mesh 20,40,60 and 80, were mixed into comparison plain concrete by the volume contents of 50,75,100 and 125 L/m3 of the aggregates, to make rubberized concrete. The specimen compressive strength is examined. The influence of rubber granule sizes, volumetric contents and the substitution pattern to the concrete strength is investigated. The results indicate that the rules of rubberized concrete must be considered when designed the mixed proportion with traditional volumetric method.

Abstract: Aluminum sheet was encapsulated by inorganic-organic hybrid film through a base catalyzed sol-gel method using organic acrylate silane resin PMBV and TEOS as precursors. FTIR and AFM characterizations prove that PMBV and TEOS have hydrolyzed and co-condensed with each other in the sol-gel process to form an uniform film on the surface of aluminum sheet. XPS result shows hydroxyl groups on aluminum surface have taken part in the co-condensation reaction.