Applied Mechanics and Materials Vols. 217-219

Abstract: Polymer alloys of polybenzoxazine and lignin were prepared by mixing benzoxazine and lignin, followed by curing. The ring-opening polymerization of benzoxazine in the presence of lignin was investigated by differential scanning calorimetry. It was found that lignin accelerates the ring-opening polymerization of benzoxazine. Polybenzoxazine/lignin alloy films were prepared by varying the weight ratio of benzoxazine and lignin. Transparent alloy film was obtained up to 2 wt. % content of lignin, but phase separation was observed at higher content of lignin. Thermal stability of the alloy films was examined by thermogravimetric analysis from 40 °C to 850 °C. The alloy film with 10 wt. % lignin showed highest onset of degradation temperature. Moreover, char yield of alloy films was increased with increasing the lignin content, suggesting higher flame retardancy of the alloy films than the pristine polybenzoxazine.

Abstract: Water-reducing agent was one of the most important concrete admixtures. Its main effect is to reduce the unit water consumption of concrete, increase strength, but also help to improve the durability, make it easy-to-mix. Water reducer has gone to polycarboxylate superplasticizer which has single side chain generally. A kind of new water reducer by choosing 2500 and 600 molecular polyethers as the side chains has the higher water-reducing effect than the traditional one. It is more than 26 on fluidity retention in 2 hours.

Abstract: In order to modify the rheological properties of epoxy resin adhesive in casting moulding technology and improve its bonding quality, the effects of thixotropic agents of hydrophilic nano-silica, organic bentonite and the composite agent of the two thixotropic ones on the rheological properties of epoxy resin (E-44) were studied by the evaluation parameters of viscosity and thixotropic index in this paper. The variation regulation of rheological properties of epoxy resin (E-44) with different thixotropic agents as the storage time was also investigated. The results show that the two thixotropic agents play a significant role in thickening the density and modifying the thixotropy of the epoxy resin (E-44). Especially, the thickening and thixotropic effects of the composite agent of 3phr hydrophilic nano-silica with 6phr organic bentonite are the most remarkable and the storage stability is also excellent.

Abstract: As the key process of weaving, sizing is one of the processes which are of great costly and serious pollution in the whole cotton-textile production chain. Great efforts had been made to study new sizing to reduce costs and environment pollution. In this paper, Methyl cellulose ether (MC) and hydroxypropyl methyl cellulose ether (HPMC) were prepared by the hemp core and further used as a textile sizing. The chemical structure of the hemp cellulose ether was characterized by the FTIR analysis. The paste viscosity was tested by the Viscometer. The sizing properties of hemp cellulose ether were evaluated by the weaving process. The results indicated that the wrap breakage rat, weft breakage rate and loom efficiency of MC and HPMC blended sizing was similar to those of PVA sizing. Compared to COD in the desizing wastewater of 3600 mg/L of PVA, the COD of hemp sizing was very small. It was 330 mg/L. Therefore, it is concluded that the hemp core ether is a new and environment-friendly textile sizing, which has low cost and contributes a healthier ecosystem.

Abstract: As a kind of environment-friendly fiber, akund will create considerable interest in the apparel industry due to its fine luster, good moisture absorption, renewable and pollution free feature. This research is a comparative study of the physical properties of akund/cotton material and pure cotton material. Results show that the enhanced structure of akund/cotton compact yarn typically results in a lower hairiness and improved mechanical properties. However, the weaving of this kind akund/cotton blended yarn may meet a lot difficulty since its tenacity value hardly meet the minimum value calls for weaving. Another important guidance is that it necessary to reduce short fiber content that may be present in the yarn structure to adopt best evenness.

Abstract: Fibrillar structure adhesives can adhere strongly to surfaces as a gecko does. The adhesion and detachment of each fiber has significant effects on the adhesion enhancement. In the present study, we report the adhesion effect of a single fiber. Based on the JKR (Johnson-Kendall-Roberts) theory, nonlinear mechanical models are built to formulate the process of adhesion and detachment between a fiber and substrate. Comparisons of the experimental and simulative results reveal consistent process trend of adhesion and detachment, which suggests the potential applicability of the present model.

Abstract: Basic properties of akund fibers are introduced briefly. Cotton and akund fibers are spun into 18.45tex, 40/60 and 18.45tex, 33/67 cotton/akund blended yarns. The influence of carding processing length is studied. When the carding processing length is longer than the main length of akund fiber, the carded sliver has the lowest short fiber and neps content. This result is proved by a series of experimental tests, such as yarn tensile strength, yarn hairiness and irregularity. The results of both yarns are compared and analyzed. The overall qualities of cotton and akund /cotton blended yarn can meet the basic requirments of aparrel and home textile

Abstract: The effect of low molecular weight (LMW) ethylene homoploymer on the structure and properties of bimodal high density polyethylene (HDPE) was studied by blending two commercial bimodal HDPE resins (tandem reactor) with two types of LWM ethylene homopolymer. The molecule weight and molecule weight distribution, crystsallinity, rheological and mechanical properties of composites were characterized by high temperature gel permeation chromatography (HT-GPC), differential scanning calorimetry (DSC), capillary rheometer respectively. For composites of bimodal HDPE and LMW ethylene homopolymer, the polydispersity index (PDI) and crystallinity can be effectively increased when reduce the molecular weight of first reactor in tandem reactor. The viscosity of composites decreases at high shear rate. Increasing of LMW component has a positive effect on processing properties and tensile strength, while makes composites brittle.

Abstract: Taking two-component additional liquid silicone rubber (LSR) as base rubber, silica white carbon black as reinforcing packing material. Analyze and compare the combustion performance and mechanical properties of three flame retardant liquid silicone rubber compound, including Magnesium Hydroxide Sulfate Whisker(MHSH), the stearic acid sodium surface treatment of MHSH(MHSH-1), MHSH-1 and organo-modified MMT (MHSH-1/OMMT). The results show that the MHSH-1/OMMT can improve the tensile strength of LSR, and have a unique advantage in improving the flame resistance of LSR.

Abstract: In this article, system layout planning (SLP) method analyzes the relationship between the refined rubber workshop logistics and the mutual relationship between logistic, draw up the position related figure of operating unit and relevant figure of operating unit area. According to the actual situation of the rubber factory, it determines three sets of optimizing distribution schemes, and uses the weighted factor method to evaluate the schemes, so as to determine the optimal arrangement scheme, each operating unit facilities layout planning unit has its guiding significance.