PU/Lignocellulosic Composites Produced from Recycled Raw Materials

Journal of Polymers and the Environment - Lignocellulosic composites are biodegradable, have low cost, neutrality to CO2 emission, easily processed, easily available and pause no health risks,...     

Characterization of EVA/PLA Blends When Exposed to Different Environments

EVA/PLA blends compatibilized with EVA-g-PLA grafted copolymers synthesized by reactive extrusion, through transesterification reaction between ethylene-vinyl-acetate (EVA) and polylactide (PLA) using titanium propoxide (Ti(OPr)₄) as catalyst, were characterized when exposed to different environments. Stability to UV radiation was assessed exposing the samples to a Xenon lamp, which simulates the sun UV spectrum and the biodegradability was evaluated by biochemical oxygen demand (BOD) in a closed respirometer. Exposed samples were removed periodically and analyzed by several analytical techniques, such as, FTIR, DSC, rheology and tensile tests. The results obtained evidenced that UV radiation induces structural modifications, which affect substantially rheological and mechanical properties. Moreover, the blend with higher amount of copolymer exhibits lower photo durability and greater biodegradability. From the environmental point of view, these new materials are very promising for application with short lifetime, like packaging.     

Insights into Effective Adsorption of Lead ions from Aqueous Solutions by Using Chitosan-Bentonite Composite Beads

Journal of Polymers and the Environment - The chitosan (Ch)—bentonite (B) composite was synthesized and its adsorption properties were investigated for lead ions. The characterization of the...     

Evaluation of the Biodegradability of Polyvinyl Alcohol/Starch Blends: A Methodological Comparison of Environmentally Friendly Materials

Polyvinyl alcohol (PVA) and starch are both biodegradable polymers. These two polymers can be prepared as biodegradable plastics that are emerging as one of the environmental friendly materials available now. In this study, after reacting with sodium trimetaphosphate (STMP), modified corn starch was blended with PVA in different ratios by a barbender. Test samples were prepared for mechanical and thermal properties measurements. The surface roughness and morphology of fractured surface of the samples were observed by an atomic force microscopy (AFM) and scanning electron microscope (SEM) measurements. Aqueous degradation by enzyme, water absorption and biodegradability behavior were evaluated for the degradability. The biodegradability of these materials was followed by bio-reactivity kinetics models. Results showed that the addition of modified starch could enhance its water uptake. With an addition of 20 wt% of modified starch, the blend had a maximum weight loss during enzymatic degradation. It was found that the degradability was enhanced with the addition of the starch. Analyzing the results of the biodegradability based on the kinetic models, the growth rate of the microorganism was found to be increasing with the increase of the content of starch in the PVA/starch blends in the first order reaction fashion. In our biodegradability analysis, i.e., based on the China national standards (CNS) 14432 regulations, we estimated the decomposition behavior based on the mentioned first order reaction. We found that the PVA/starch blends would take 32.47, 16.20 and 12.47 years to degrade by 70% as their starch content 0, 20 and 40 wt%, respectively.     

N-甲基二乙醇胺-二乙醇胺复合溶液脱除采出气中的CO2

结合中国石化胜利油田CO2驱现场情况,采用耐压实验装置模拟CO2驱采出气.在中压条件下对N-甲基二乙醇胺(MDEA)及MDEA与二乙醇胺(DEA)的复合溶液脱除模拟采出气中CO2的效果进行了实验研究,对吸收饱和液进行了再生实验.在模拟采出气中V(CH4):V(CO2)=3:7、反应温度为70.0℃、反应压力为0.5 MPa、MDEA-DEA复合溶液中MDEA质量分数为40％、DEA质量分数为2％的条件下,CO2吸收体积为48.429 71 L,再生温度为106.0℃,再生能耗为0.010 12 kW·h/L,再生率为98.84％.