利用碱性蚀刻废液制备纳米铜导电浆料

利用液相还原的方法先在碱性蚀刻废液中制备成纳米级的铜粉,再通过对纳米铜粉表面的保护和真空干燥,然后将铜粉分散到聚氨基甲酸酯以及浆料助剂中得到纳米铜导电浆料。实验研究表明通过液相法制备出了的铜粉纯度比较高,大部分颗粒尺寸在100 nm以内,制备出来的导电浆料其体积电阻率可以达到18.35×10-3Ωcm。

Closed Loop Recycling of Chlorine for Sustainable Development of Polyurethane Industry

Increasing demand is fueling the booming polyurethane industry worldwide. An impeding issue for poly- urethane industry is how to handle the large quantity of hydrogen chloride byproduct generated from the synthesis of intermediates, i.e., isocyanates. In the meantime, the traditional chloro-alkaline process sufibrs both from the high en- ergy intensity of electrolysis method and the disparity in the chlorine and caustic soda market. To solve these prob- lems, the state-of-the-art chlorine recycling technologies are reviewed and compared. Approaches for cost-effective utilization of chlorine in polyurethane industry are investigated. Chinese academies and enterprises＇ on-going effort on the development of a novel hydrogen chloride oxidation process for the synthesis of chlorine is presented. With this process, the closed loop recycling of chlorine can be realized. Tremendous economic, environmental and social bene- fits can be expected. A wide adoption of this technology will significantly advance the sustainable development of polyurethane industry.

Effect of dosage of expandable graphite,dimethyl methylphosphonate,triethanolamine,and isocyanate on fluidity,mechanical,and flame retardant properties of polyurethane materials in coal reinforcement

In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding strengths,oxygen index,and fluidity of rigid polyurethane foam(RPUF).The results revealed that EG significantly increased the oxygen index of RPUF,enlarged the diameter of foam cells,and decreased the cell-closed content in foam;thus,leading to a pressure drop in RPUF.However,excessive EG was capable of reducing the fluidity of polyurethane slurry.TEA exhibited significant influence on the compressive strength of RPUF,which dropped initially,and then increased.DMMP had a remarkable effect on the flame retardant property and compressive strength of RPUF.Compressive strength of RPUF initially displayed an increase followed by a decrease with increasing dosage of DMMP,and achieved the maximum value at DMMP dosage of 4%.DMMP could effectively reduce the diameter of RPUF cells leading to an increase in the percentage of close area in foam.DMMP displayed the flame-retardation effects mainly in the gas phase leading to a significant enhancement in the oxygen index of RPUF.Moreover,the compressive strength and bonding strength of RPUF decrease significantly with the increase of isocyanate content due to the increased blowing efficiency by the CO_2.The oxygen index and flowing length of foam increased with the increase in isocyanate dosage.

Preparation and Properties of Tung Oil-Based Polyurethane

Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oilbased anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly(propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly(propylene glycol) on the properties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The results show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane.

Water-soluble UV curable urethane methyl acrylate coating：preparation and properties

Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous so-lutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.

Synthesis of Water-dispersed Polyurethane Adhesive and Its Application in Pigment Printing

Water-dispersed polyurethane (PU) adhesive is a novel and highly efficient adhesive with broad application potential. In this study, the key parameters affecting the synthesis and application of this adhesive were examined, and optimal conditions were identified. The water-dispersed PU adhesive was successfully synthesized, and applied in the fastness test of pigment printing on cotton fabric. The data demonstrated that all the fastnesses of PU adhesive were better than that of the conventional PA one.

Synthetic biodegradable functional polymers for tissue engineering:a brief review

Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly(glycerol sebacate) are summarized in this article. New developments in conducting polymers, photoresponsive polymers, amino-acid-based polymers, enzymatically degradable polymers, and peptide-activated polymers are also discussed. In addition to chemical functionalization, the scaffold designs that mimic the nano and micro features of the extracellular matrix(ECM) are presented as well, and composite and nanocomposite scaffolds are also reviewed.

Achievement of a near-perfect smooth silicon surface

During the ultra large scale integration （ULSI） process, the surface roughness of the polished silicon wafer plays an important role in the quality and rate of production of devices. In this work, the effects of oxidizer, surfactant, polyurethane pad and slurry additives on the surface roughness and topography of chemical-mechanical planarization （CMP） for silicon have been investigated. A standard atomic force microscopy （AFM） test method for the atomic scale smooth surface was proposed and used to measure the polished silicon surfaces. Finally, compared with the theoretical calculated Ra value of 0.0276 rim, a near-perfect silicon surface with the surface roughness at an atomic scale （0.5 4） was achieved based on an optimized CMP process.

Synthesis of biodegradable poly (methylparaben/glycine ethyl ester) phosphazene and further research of its degradation in vitro

Polydichlorophosphazene(PDCP)was synthesized from PCl5 and NH4Cl via a one-pot approach,and then further reacted with glycine ethyl ester and methylparaben via a two-step nucleophilic substitution approach to give poly(methylparaben/glycine ethyl ester)phosphazene(PMGP),which was a kind of mix-substituted biodegradable polymer.NMR and FT-IR were used to characterize its structure.A series of experiments were conducted to study the effects of the ratio of methylparaben to glycine ethyl ester and the experimental conditions to the degradability of PMGP samples.The degradability of PMGP can be adjusted by altering the ratio of methylparaben to glycine ethyl ester easily.