The Effect of Rotation and Temperature on the Inhibition Performance of Cashew (Anacardium Occidentale L.) Nut Shell Liquid on Co2 Corrosion of Carbon Steel

A natural extract of cashew nut shells, Cashew Nut Shell Liquid (CNSL) was investigated as a corrosion inhibitor for carbon steel in 3% NaCl solutions saturated with CO2 gas using electrochemical techniques (i.e. potentiodynamic polarization and ac-impedance). The investigation was performed at different temperatures under static and dynamic conditions using a Rotating Disk Electrode (RDE). It was found that CNSL reduces the electrochemical processes taking place on carbon steel undergoing corrosion. The percentage inhibitorefficiency increases with increase in CNSL concentration and decreases with rise in temperature. Better performance at low CNSL concentration was registered under dynamic conditions and room temperatures. Thus CNSL is a potential corrosion inhibitor for carbon steel undergoing corrosion in CO2 medium

The influence of aliphatic side chain of anacardic acid on molecular recognition properties of imprinted polymers

The objective of this work was to determine the influence of the aliphatic side chain of anacardic acid on molecular recognition properties of imprinted polymers made from anacardanyl methacrylate (AnMcr). Salicylic methacrylate (SaMcr), a structural analog of AnMcr, was synthesized and used as a functional monomer to prepare imprinted polymers for comparison with AnMcr-based polymers. Using divinylbenzene (DVB) as a cross linker and racemic propranolol as a model template, irregular monolithic particles of poly(SaMcr-co-DVB)m were synthesized in toluene, and spherical beads of poly(SaMcr-co-DVB)b and poly(AnMcr-co-DVB)b weresynthesized in acetonitrile by precipitation polymerization. Although imprinted irregular monolithic particles, poly(SaMcr-co-DVB)m, tested in toluene containing 0.5% acetic acid, displayed relatively low specific propranolol binding, they showed high molecular selectivity. For the spherical beads tested in acetonitrile, both imprinted poly(AnMcr-co-DVB)b and poly(SaMcrco-DVB)b showed obvious specific propranolol binding despite the use of polar organic solvent during imprinting. Imprinted poly(AnMcr-co-DVB)b showed higher molecular selectivity than imprinted poly(SaMcr-co-DVB)b. Interestingly, the presence of the aliphatic side chain in AnMcr resulted in more uniform imprinted beads as compared to particle agglomerates obtained from SaMcr in the presence of propranolol template. Therefore, the aliphatic side chain of anacardic acid improves both molecular recognition of imprinted polymers as well as the formation  of uniform imprinted spherical beads.Keywords: Molecular imprinting, anacardanyl methacrylate, salicylic methacrylate, propranolol, precipitation polymerizatio

METAL ION SEQUESTRATION: AN EXCITING DIMENSION FOR MOLECULARLY IMPRINTED POLYMER TECHNOLOGY

ABSTRACT were recorded for five re-cycles

MICRON-SIZED POLYMER PARTICLES FROM TANZANIAN CASHEW NUT SHELL LIQUID. PART II: AN ASSESSMENT OF CATION-EXCHANGE CAPABILITY OF THE CARBOXYLATED PARTICLES

Micron sized polymeric particles were prepared from cashew nut shell liquid and subsequently functionalized to produce micron-sized carboxylated cation exchange resin (MCCER). By titrimetry and analytical procedures employing atomic absorption spectrometry, an assessment of the cation exchange capability of the carboxylated particles was made. The total cation exchange capacity of MCCER was found to be 5.4 ± 0.1 meq/g. The apparent acid strength exponent (pK) of the resin was estimated to be 5.6 ± 0.1 at 30 °C. The resin was found to be nonselective toward calcium, magnesium and sodium ions and the affinity of the resin toward competitive exchange of the ions followed the order: Ca2+ > Mg2+ > Na+. The results indicate that cation exchange capacity of MCCER is comparable to other commercially produced carboxylic cation exchange resins. KEY WORDS: Carboxylated cation exchange resins, Cation exchange capacity, Cashew nut shell liquid Bull. Chem. Soc. Ethiop. 2005, 19(1), 9-15

Preparation of molecularly imprinted polymers using anacardic acid monomers derived from cashew nut shell liquid

The objective of this work was to use monomers from cashew (Anacardium occidentale L.) nut shells to develop molecularly imprinted polymers. Cashew nut shell liquid (CNSL) is a cheap and renewable agro byproduct consisting of versatile monomers. Solvent-extracted CNSL contains over 80% anacardic acid (AnAc) with more than 90% degree of unsaturation in its C-15 side chain. From AnAc monomer, anacardanyl acrylate (AnAcr) and anacardanyl methacrylate (AnMcr) monomers were synthesized and their chemical structures were characterized by Fourier transform IR and NMR. Different imprinted bulk polymers based on AnAc, AnAcr, and AnMcr functional monomers have been prepared. In the present study, each functional monomer was separately copolymerized in toluene with ethylene glycol dimethacrylate and divinylbenzene as cross-linkers, using racemic propranolol as a model template. While the AnAc based polymer revealed a meager rebinding ability, the imprinted polymers made from AnAcr and AnMcr displayed highly specific propranolol binding. At a polymer concentration of 2 mg/mL, AnAcr and AnMcr based imprinted polymers were able to bind over 50% of trace propranolol (initial concentration 1.2 nM). Under the same condition propranolol uptake by the two nonimprinted control polymers was less than 20%. Chiral recognition properties of these polymers were further confirmed using tritium-labeled (S)-propranolol as a tracer in displacement experiments, suggesting that the apparent affinity of the imprinted chiral sites for the correct enantiomer is at least 10 times that of the mismatched (R)-propranolol. Moreover, cross reactivity studies of these polymers showed that the (S)-imprinted sites have higher cross-reactivity toward (R,S)metoprolol than (R)-propranolol and (R)-timolol