Effects of Boric Acid Ester Modified Magnesium Borate Whisker on the Mechanical Properties and Crystallization Kinetics of Polypropylene Composites

Polypropylene (PP) is notch sensitive and brittle under severe conditions of deformation, limiting wider range of its usage as a structural load-bearing polymer. Hence, in this work the magnesium borate whisker (MBw), with similar mechanical properties to carbon fiber but much less expensive than polycrystalline silicon carbide, was modified by boric acid ester (BAE) and then used to fabricate PP composites. The mechanical properties, morphology, and non-isothermal crystallization property of virgin PP, PP/MBw, and PP/BAE-MBw composites were studied through mechanical testing, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC), respectively. The non-isothermal crystallization data was analyzed via Mo, Kissinger, and Dobreva methods. The results reveal that the incorporation of BAE-MBw into PP matrix results in higher tensile strength and impact strength than those of virgin PP and PP/MBw composite. The activation energies based on Kissinger were 190.20 kJ/mol for virgin PP, 206.59 kJ/mol for PP/MBw, and 218.98 kJ/mol for PP/BAE-MBw. The nucleation activities of whiskers determined by the Dobreva model were 0.86 for PP/MBw and 0.75 for PP/BAE-MBw. As a result, the whiskers, especially the modified whiskers, act as active substrates to facilitate heterogeneous nucleation, which leads to an increase in crystallization rate.

Recovery of Boron from Underground Brine by Continuous Centrifugal Extraction with 2-Ethyl-1,3-hexanediol (EHD) and Its Mechanism

In order to economical and environmental-friendly recycle of boron from underground brine, the extraction of boron was carried out in this work by the continuous centrifugal technique using 2-ethyl-1,3-hexanediol (EHD) + sulfonated kerosene (SK) extraction system, and the extraction mechanism was also investigated by the combination of FT-IR with slope method. The results showed that boron can be effectively extracted from underground water with the concentration of boron 5.43 g·L−1 by five-stage centrifugal extraction using 30% EHD + 70% SK at pH = 2.0–3.0, R(O/A) = 1 : 2, and the extraction rate reached 98.46%. Boron in the organic phase can be well five-stage back-extracted by 1.0 mol·L−1·NaOH at R(O/A) = 1 : 1 with a back-extraction rate of 97.00%. About 88.32% boron in the aqueous phase obtained by back-extraction can be recycled in H3BO3 form by evaporation crystallization after acidified to pH < 2.5. The extraction mechanism indicated that the extraction is completed mainly based on the esterification reaction between alcoholic hydroxyl in EHD and -OH in B(OH)3 at the stoichiometric ratio 1 : 1 to generate a stable six-membered ring structure of boric acid ester.

Protective Efficiency of Water-Soluble Corrosion Inhibitors

Introduction. As a result of damage to agricultural and forestry machines from corrosion, the costs of maintaining their performance are increasing. The use of water-soluble inhibitors can slow or halt the destructive process. However, many of the inhibitors have disadvantages, for example, flammability or toxicity. The purpose of this work is to study the protective effectiveness of aqueous solutions of boric acid ester and triethanolamine and to develop recommendations for their use for anticorrosive protection of agricultural and forestry machinery in long-term storage. Materials and Methods. Protective compositions were prepared by dissolving boric acid ester and triethanolamine in distilled and industrial water at room temperature. Aqueous solutions with a concentration of water-soluble inhibitors of 5–50 g/l (0.5–5 mass %) were used for research. The linear polarization resistance method was used to assess their protective efficiency. Solartron (UK) measuring complex was used for electrochemical studies. Accelerated corrosion tests were carried out on steel plates according to GOST 9.054-75 in the g-4 humidistat. The aftereffect of water-soluble corrosion inhibitors was evaluated by the residual film protective efficiency. Results. The influence of the concentration of the ester of boric acid and triethanolamine in aqueous solutions for their protective properties is studied. It was found that boric acid and triethanolamine slow the anode reaction. The analysis of the research results has showed that the corrosion rate of the steel electrode decreases with increasing the concentration of water-soluble inhibitor in process water. This decrease is the most noticeable when the concentration in the range of 10–50 g/l with an increase in the concentration in the solution of boric acid and triethanolamine to 50 g/l, their protective efficiency varies by 6–14 %. The optimal concentration of the inhibitor in the composition is obtained, which is 10 g/l during corrosion tests of steel plates, the protective efficiency of the solution with a concentration of 10 g/l of the water-soluble inhibitor was more than 70 %. In case of precipitation on the samples, the protective efficiency of the solutions decreased to 20–25 %. When tested in a closed unheated room on steel samples during the year there were no traces of corrosion. Conclusions. The study demonstrates that boric acid and triethanolamine is a watersoluble inhibitor of anodic corrosion. When the concentration of water-soluble inhibitor in process water increases, the corrosion rate of the steel electrode decreases. Optimum concentration of ester of boric acid and triethanolamine in the protective solution should be 10 g/l. For corrosion tests of steel plates, the shielding effectiveness of a solution of water- soluble inhibitor was more than 70 %. In the conditions of direct exposure to atmospheric precipitation on the samples of the protective efficiency of the solutions decreased to 20–25 %. When tested in a closed unheated room on steel samples there were no traces of corrosion during the year. Thus, the ester of boric acid and triethanolamine is effective to protect against atmospheric corrosion in a closed room. it Is recommended to apply it for protecting cars against corrosion at short-term storage on open platforms. The application field of water-soluble inhibitor when agricultural and forestry machines are retained for long-term storage is defined; combine stages of cleaning cars from pollution and preserving their surfaces for protection against corrosion are offered. The article will be useful to specialists in the field of protection of agricultural machinery from corrosion.

Aqueous phase reforming of glycerol using doped graphenes as metal-free catalysts

Boron-doped graphene obtained by pyrolysis at 900 °C of the boric acid ester of alginate was found to be the most active graphene among a series of doped and co-doped graphenes to promote the aqueous phase reforming of glycerol at 250 °C.

A New Type of Compatilizer and its Application in Polystyrene Ether/Nylon 66 Alloy

This paper studies the influence of Double (L- diethyl tartrate) boric acid ester (compatibilizer B) on the compatibility between PPO and PA66. Through the mechanical properties, Molau experiment, scanning electron microscope and tem analysis test method, it is proved that Double (L- diethyl tartrate) boric acid ester can be used as a new reactive compatibilizer in PPO/PA66 plastic alloy.

New Reactive Compatibilizer B Preparation and its Application in Polystyrene Ether/Nylon 66 Alloy

A new type compatibilizer-boric acid ester with carboxylic acid functional groups (refered as B) was synthesized and used in PPO/PA66 alloys. The PPO/PA66 alloys were produced by melting blending. The micromorphological and mechanical properties of PPO/PA66 blends with different contents of the compatibilizer were studied by transmission electron microscope (TEM), scanning electron microscope (SEM) and mechanical test. The effects of the compatibilizer B on the mechanical property and morphology of PPO/PA alloy were discussed. The results showed that, the compatibilizer B can also improve the mechanical property, besides showing good effect on the compatibility improvement for PPO/PA blends; it (B) acts as a compatibilizer for the blends by forming interim layer with dispersed phase PPO and continuous phase PA. The compatibilization of PPO and PA66 alloy was due to the chemical reaction between carboxyl group and amine group.

Research on the Performance of an Eco-Friendly Nitrogen Organic Boric Acid Ester Antirust Additive

Nitrogen organic boric acid ester was synthesized by hydroxymethylation BTA and oleic acid polyacrylamide boric acid ester two ethanol. Results showed that all of the capabilities were good when the synthesis of product’s additive quantity was 0.25%, and antirust properties kept well under a little higher temperatures and longer working-time. The product could be used as anti-rust and lubricating additives for water-based cutting fluid.