Synthesis and characterization of new oligomeric/polymeric antistatic additives for sheet molding composites

For various applications it is necessary to lower the specific surface resistivity of polymers in an electrostatically conductive area. To improve the antistatic properties of sheet molding composites (SMC) usually conductive inorganic additives, like carbon black, inorganic salts, metal powder, or CNTs, are mixed physically into the matrix. A newly developed concept for antistatic treatment is using oligomeric/polymeric additives, which are synthesized on the base of ingredients of the used polymeric matrix itself. The received additives are compatible with the matrix. Furthermore, the migration of the additives to the surface is prevented and in the case they exhibit double bonds they are able to be linked in the polymeric network permanently by covalent bonds. So unsaturated, polymer‐based antistatic additives with ionic units were developed for unsaturated polyester resin based SMC. The synthesis was realized by polymer analogous reactions and polycondensation reactions from monomer building blocks with ionic units. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44741.     

Biopolymers as alternatives to synthetic polymers in flame-retarded polymeric composites: A study of fire and mechanical behaviors

The impact of polymeric materials on the environment is a growing concern and an incentive for their commercial appeal. In composites, the trend is to replace matrices of synthetic polymers (SPs) with biopolymers (BPs) to develop bio-based composites. The increasing demand for such materials has driven their research and application in many industrial sectors, often accompanied by increasingly restrictive fire safety regulations. With the aim of decreasing the flammability of composites, various approaches have been pursued, in particular the use of flame-retardant (FR) additives. However, at high FR loads, the mechanical properties can be compromised. This article briefly overviews some aspects of the fire behavior and mechanical properties of BPs and bio-based composites. Using a chart-based framework and quadrant-based quantitative analysis, the fire and mechanical properties of flame-retarded composite formulations are evaluated simultaneously, aimed at comparing the effects of BPs and SPs in flame-retarded polymeric composites in relation with other variables.     

高温浓硫酸用XDS不锈钢板材的研究

根据合金设计的理论，对高温浓硫酸用不锈钢进行全面的改性研究，进而开发出新型耐高温浓硫酸用不锈钢板材XDS。比较并论述了XDS不锈钢在高温浓硫酸中的力学性能和耐腐蚀性能，认为XDS不锈钢已达到国际先进水平，为制造硫酸厂的干吸塔、酸泵等设备提供了优异的钢材，也为低温热回收系统的应用创造了条件。     

Wood flour: New filler for the rubber processing industry. IV. Cure characteristics and mechanical properties of natural rubber compounds filled by non‐modified or corona treated wood flour

It is presented here how some cure characteristics and mechanical properties of rubber compounds based on nonpolar rubber, natural rubber (NR), are affected by filling with conifer wood flour, both nonmodified or corona treated in air or in ammonia. The corona treatment was performed at room temperature and varied both: treatment duration and voltage to find out the maximal reinforcing effect of the modified wood flour. The discharge voltage was varied at 10, 12, and 15 kV to include both (1) the range of relative low voltages (lower than 10 ÷ 12 kV in which the major active species arise from ionized and activated air oxygen and (2) the range of relative high voltages (12 kV and higher) in which the active species arise from simultaneously ionized and activated air oxygen and nitrogen. The chemical composition of the nonmodified and corona‐treated wood surface was controlled by X‐ray photoelectron spectroscopy (XPS) analysis. The activity of the modified wood flour was evaluated by comparative measurement of some basic mechanical parameters of rubber compounds, filled at equal level by nonmodified or plasma‐treated wood flour. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 651–658, 2006