Applied Mechanics and Materials Vols. 174-177

Abstract: Take liquid phase separation method to prepare polyurethane microporous membrane. In the preparation of microporous membrane process phosphorus add modification flame retardant agent in order to improve the polyurethane flame retardant properties. Experiments prove that the add of flame retardant can increase the flame retardant performance of polyurethane greatly. when phosphorus add quantity of flame retardant agent for 8 % polyurethane microporous membrane flame retardant was the best effect. And microporous membrane other performance also have no obvious effect. Because of flame retardant performance was good, this kind of polyurethane can be widely used in floor synthetic leather, wall paper, decoration, etc.

Abstract: Physical and mechanical properties including volume density, compressive strength and linear shrinkage of sintered clay body (SCB) mixed with sewage sludge incineration ash (SSIA) at the highest calcination temperature of 1050°C have been investigated. The result shows that 40% is the maximum percentage of SSIA in the SCB for meeting the compressive strength MU10 in the national standard GB5101-2003.

Abstract: Microporous Poly (vinyl chloride) (PVC) was prepared by foaming of PVC powders using the solution of 2, 2’-azo-bis-iso-butyronitrile (AIBN) in co-solvent of butanone and cyclohexanone when heated. The effect of composition of solvent and quantity fraction of AIBN also preferred dioctyl phthalate (DOP) on the structure of microporous PVC is discussed. The results indicated that much microporosity with average size of 0.2-2μm can be generated when acetone is selected as solvent, 2% DOP and 10% AIBN are used. The microporous PVC is a potential desirable reactor to prepare CaCO3 nanoparticle.

Abstract: The objective of this study was to reinforce biodegradable polyvinyl alcohol (PVA) with nano cellulose fibrils generated from poplar and cotton through mechanochemical treatment. A method used a combination of acid and alkali treatment to obtain cellulose from poplar and cotton. The cellulose of both fibers was further processed by grinder treatment. PVA/nano cellulose composite was prepared successfully by an immersion method. The cellulose nanofibers and nanocomposite films were characterized with scanning electron microscope (SEM), tensile testing machine, ultraviolet-visible spectrophotometry (UV-vis). SEM showed the diameter of the cellulose was range between 30-100 nm and exhibited a high aspect ratio of over 1500. The mechanical properties of PVA were improved significantly and the two plant nanofibers had the similarly reinforcing effects in the matrix. Cellulose nanofibers as a future resource have tremendous potential since they are one of the most abundant organic resources on the earth.

Abstract: Weather resistance properties of the sintered clay body (SCB) mixed with various content of sewage sludge incineration ash (SSIA) has been investigated. The result indicates that the water absorption ratio of SCB mixed with SSIA increased linearly with the increase of the content of SSIA, while the saturation coefficient remained constant. After the freeze-thaw cycles, the SCB body mixed with SSIA showed a stable and smooth appearance. From the SEM results, the internal porosity and pore size of SCB raised significantly with the increase of content of SSIA.

Abstract: Recycled concrete was waste concrete re-processing to restore the original performance, so that the waste of resources to re-use. It’s important to study the recycled concrete fire resistance, by analyzing the frequency of the existing building fire, the extent of waste concrete increasing year by year. Through the analysis of recycled concrete as structural components in the deficiencies of strength, seismic and fire resistance, indicates the importance of anti - fire properties of recycled concrete - filled steel tube.

Abstract: This paper reports the preparation for cellulose nanofibers (CNFs) and fabricates CNFs reinforced polylactic acid (PLA) composites with the goal of making sustainable ’green-composites’. CNFs were isolated from wood powder by acid and alkali processing combined with mechanical treatment，containing grinding treatment and high-pressure homogenizing. The nanocomposites were prepared by incorporating 1wt% of the CNFs into the PLA matrix by a dichloromethane solution casting method. Fourier transform infrared spectroscopy（FT-IR）and scanning electron microscopy (SEM) were studied to see the structure of CNFs. The FT-IR indicates that the original molecular structure of cellulose is maintained even after matrix components removal and different mechanical treatments and the SEM images show that the aspect ratio of CNFs is over 1,200. The mechanical properties and the coefficient of thermal expansion (CTE) of the neat PLA and CNFs/PLA composite films were investigated. The results indicate that tensile strength and modulus of PLA are improved and the CTE of PLA is decreased with the addition of CNFs. From the results, CNFs show considerable potential as an effective reinforcement for high quality specialty applications of PLA.

Abstract: In this work, the preparation and properties of cellulose nanofibers (CNFs) which have a diameter of less than 100 nm, CNFs sheet and PMMA based nanocomposites sheet were presented. To fabricate CNFs, chemical treatments combined with grinding treatment were used in this research. The CNFs sheet was successfully fabricated by vacuum filtration, and to fabricate the PMMA based nanocomposites sheet, the CNFs sheet was immersed in the PMMA solution, and cured by heat. The tensile strength and Young’s modulus of CNFs sheet is 64.9 MPa and 4438 MPa, respectively. Due to the reinforcement function of CNFs, the tensile strength and Young’s modulus of neat PMMA sheet is improved by 60% and 190%, respectively. The light transmittance of CNFs sheet and PMMA based nanocomposites sheet is 82.1% and 89.2%, respectively.

Abstract: Pre-stressed fabric reinforced concrete sheet is used to make permanent model or to reinforce the existing buildings, it will make the surface of reinforced concrete with steel bar tightness and better cracking resistance, it is beneficial to fully manifest the effect of high strength and high modulus before the sheet cracking; the pre-stressed method improves sheet rigidity, it is beneficial for the sheet to cooperate with structure of reinforced concrete. The paper introduced the designing process of carbon/glass braided fabric composite material, and illuminated selecting raw material, means of making fabric, specification and selecting impregnating agent, meanwhile it made simple measurement to the fabric.

Abstract: The goal of this paper was to develop an optically transparent nanocomposite with high strength by reinforcing polyurethane (PU) with cellulose nanofibers (CNFs) extracted from newspapers. The FE-SEM images show that through chemical and mechanical treatments, newspaper CNFs with diameters ranged from 20 to 100 nm and an aspect ratio of over 1000 were successfully obtained as well as wood powder. They were cross-linked together and formed a special three-dimensional network structure. The nanocomposite was fabricated by impregnating the CNF sheet into transparent PU resin and cured under ultraviolet. Results demonstrate that the transparency of newspaper CNF/PU nanocomposite was as high as wood CNF/PU nanocomposite. The elastic modulus and tensile strength of newspaper CNF/PU composite were increased roughly eighteen times and two times respectively while retaining the high transparency of PU, which was nearly the same with wood CNF/PU composite.