Water-soluble Amines Research Articles

Semisynthesis of new sulfated heterorhamnan derivatives obtained from green seaweed Gayralia brasiliensis and evaluation of their anticoagulant activity

Marine green algae produce sulfated polysaccharides with diverse structures and a wide range of biological activities. This study aimed to enhance the biotechnological potential of sulfated heterorhamnan (Gb1) from Gayralia brasiliensis by chemically modifying it for improved or new biological functions. Using controlled Smith Degradation (GBS) and O-alkylation with 3-chloropropylamine, we synthesized partially water-soluble amine derivatives. GBS modification increase sulfate groups (29.3 to 37.5 %) and α-l-rhamnose units (69.9 to 81.2 mol%), reducing xylose and glucose, compared to Gb1. The backbone featured predominantly 3- and 2-linked α-l-rhamnosyl and 2,3- linked α-l-rhamnosyl units as branching points. Infrared and NMR analyses confirmed the substitution of hydroxyl groups with aminoalkyl groups. The modified compounds, GBS-AHCs and GBS-AHK, exhibited altered anticoagulant properties. GBS-AHCs showed reduced effectiveness in the APTT assay, while GBS-AHK maintained a similar anticoagulant activity level to Gb1 and GBS. Increased nitrogen content and N-alkylation in GBS-AHCs compared to GBS-AHK may explain their structural differences. The chemical modification proposed did not enhance its anticoagulant activity, possibly due to the introduction of amino groups and a positive charge to the polymer. This characteristic presents new opportunities for investigating the potential of these polysaccharides in various biological applications, such as antimicrobial and antitumoral activities.

Water-soluble and hydrolysis-resistant activated ester polymers: Synthesis, characterization, and application for preparing functional polymers

Post-polymerization modification of pendant-activated ester groups on polymer backbones is a versatile tool to obtain multifunctional water-soluble polymers that cannot be synthesized by typical methods of polymerization. For the first time, short-chain PEG functionalized hydroxybenzoic acid esters (PHBE) were employed to synthesize novel monomers and polymers. The corresponding PHBE-bearing polymers were successfully synthesized for post-polymerization modification by free radical polymerization. More significantly, acrylic PEG functionalized hydroxybenzoic acid esters polymers showed traceless hydrolysis at room temperature for more than 10 days. Furthermore, the multifunctional PHBE-bearing polymers could be directly conjugated to water-soluble amines in water at room temperature. Therefore, this procedure provides an alternative route to well-defined, multifunctional, water-soluble polymers for a range of applications.

Rigid twisted structured PA membranes for organic solvent nanofiltration via co-solvent assisted interfacial polymerization

Interfacial polymerization has always been a research hotspot for the preparation of polyamide (PA) membranes for molecular sieving. In previous reports, water-soluble amines (such as piperazine (PIP), m-phenylenediamine (MPD), etc.) were mostly used as monomers containing amino functional groups in the aqueous phase to conduct interfacial polymerization with 1,3,5-mesotribenzoyl chloride (TMC) in hexane, resulting in a dense PA film. However, this approach limits the diversity of polymer structures in PA films. To introduce water-insoluble 9,9-Bis(4-aminophenyl)fluorene (BAF) with a rigid twisted structure into interfacial polymerization, this study reports the interfacial polymerization of BAF in DMF/water solution with TMC in n-hexane. BAF-PA films with a larger free volume compared with MPD-PA were successfully prepared. The anomalous interfacial diffusion phenomenon was explained by the interfacial properties and molecular diffusion mechanism of the two-phase solvent and was confirmed by observing the microscopic morphology of the film. Since the structure of BAF-PA has a larger free volume, the BAF-PA film prepared by co-solvent interfacial polymerization has higher permeance to methanol (23.88 L m−2 h−1 bar−1). Meanwhile, it has more than 90% rejection of dyes with molecular weights of 585 Da and above. The large free volume PA film prepared with DMF/water mixed solvent exhibited excellent performance in organic solvent nanofiltration. This method also offers the possibility of introducing other water-insoluble amines into the interfacial polymerization to prepare PA films.

Monitoring and investigating reactive extraction of (di–)carboxylic acids using online FTIR – Part II: Reaction equilibria, reaction kinetics and competition within the complex formation between itaconic acid and several amine extractants

The downstream processing of biocatalytically produced (di–)carboxylic acids still is a challenging task. One innovative approach, demonstrating industrial applicability, applies an initial reactive extraction (RE) using hydrophobic amine extractants into an organic solvent, followed by a subsequent back-extraction (BE) using water soluble amine extractants into a (fresh) aqueous solution. Although showing promising results in terms of yield and selectivity, state-of-the-art amine extractant selection is only based on trial-and-error screening approaches. Thus, to enable an optimized process design and thereby optimized downstream processing, a deeper understanding of RE and BE on a molecular level is crucial.Within this work, we successfully applied an experimental setup incorporating online Fourier Transform Infrared (FTIR) spectroscopy to elucidate influencing factors on RE and BE as well as to provide a guideline for an optimized selection of amine extractants. Investigations on the kinetics of complex formation between itaconic acid (IA) and tri-n-octylamine (TNOA) in 1-decanol revealed the reaction order to be zero in TNOA, indicating that mass transfer is the rate limiting step in RE. Reaction equilibrium investigations revealed that for all IA - amine extractants combinations in 1-decanol reaction equilibrium was almost completely on the product (complex) side. The strength of the acid-extractant complexes was evaluated using FTIR experiments, providing a novel approach / methodology to efficiently select an optimal combination of amine extractants for RE and BE. Applying the novel online FTIR spectroscopy setup allowed to monitor a complete process sequence of RE and BE of IA with selected amine extractants, validating the proposed guidelines for an optimized selection of amine extractants. The results of this work will facilitate the definition of appropriate RE and BE systems for biocatalytically produced (di–)carboxylic acids.

Biobased diglycidyl ether diphenolates: Effect of the ester moiety on fragrance oil microencapsulation by interfacial polymerization

Health risks are associated with capsule-forming synthetic chemicals such as formaldehyde, isocyanates, and bisphenol A (BPA). This work is focused on using safe biobased molecules to build capsule walls for oil encapsulation. Cellulose-derived diphenolic acid was converted into a series of diglycidyl ether n-alkyl diphenolates (DGEDP-esters). Interfacial polymerization of oil-soluble DGEDP-esters and water-soluble amine hardeners, hexamethylenediamine (HMDA) and chitosan oligosaccharide (COS), were used to build capsule walls. DGEDP-esters with small methyl and polar monomethyl ethylene glycol (DGEDP-ME and DGEDP-MG, respectively) are most reactive forming compact crosslinked capsules with high microencapsulation efficiency (EE of 97% and 94.3%) and good stability (oil leaking was ≤ 15.7% after acidification, and ≤ 64.2% after sonication). With increased hydrophobicity of the DGEDP ester moiety, deformed capsules with low EE (63 – 87%) and poor stability (oil leaking was ≥ 18.4% after acidification, and ≥ 81.8% after sonication) were obtained. Oil encapsulated with DGEDP-esters exhibits oil release of 0.5 – 8% at day 30 (45 °C and 11 kPa). The use of COS as the hardener yields capsules with EE (88.3 – 94%) and higher oil release (9–15% at day 30) compared to HMDA, but the acid stability was remarkably improved (oil leaking ≤ 3.7%). Cytotoxicity tests suggest that capsules formed with DGEDP-ME and HMDA or COS show very low cytotoxicity against human breast cancer cells and human fibroblasts cells (cell viability of 87–102% after 24 h exposure at capsule concentration of 2 mg/mL). These observations demonstrate that the structures of DGEDP epoxy monomers and amine hardeners have significant effects. Preferred DGEDP ester groups were methyl and mono-methoxy, and effective capsule formation was achieved using either HMDA or COS, the latter providing the advantage of being a readily renewable biobased multifunctional amine.

Formulating A Novel Fluorinated Silica Nanoparticle using Fluoroalkylsilane as a Wettability Alteration Agent

A novel fluorinated silica nanoparticles were synthesized using 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS17) and further characterized to evaluate the wettability alteration capability. Previous research (1, 2) has utilized fluoroalkanoic acids as the coating agent. First, the in-situ functionalization method employs tetraethoxysilane (TEOS) as the silica precursor and water-soluble amine as the catalyst. It is then further functionalized with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS17) with ethanol to attain the novel fluorinated silica nanoparticles. The preliminary characterization from FTIR analysis indicated that the in-situ functionalization was successfully applied. The new bonding formation with fluorine attachment on the novel fluorinated silica nanoparticles is capable to alter the wettability of the solid surface, exhibiting self-cleaning properties.

Cosolvent-Driven Interfacial Polymerization for Superior Separation Performance of Polyurea-Based Pervaporation Membrane.

A thin-film composite (TFC) polyurea membrane was fabricated for the dehydration of an aqueous tetrahydrofuran (THF) solution through interfacial polymerization, wherein polyethyleneimine (a water-soluble amine monomer) and m-xylene diisocyanate (an oil-soluble diisocyanate monomer) were reacted on the surface of a modified polyacrylonitrile (mPAN) substrate. Cosolvents were used to tailor the membrane properties and increase the membrane permeation flux. Four types of alcohols that differed in the number of carbon (methanol, ethanol, isopropanol, and tert-butanol) were added as cosolvents, serving as swelling agents, to the aqueous-phase monomer solution, and their effect on the membrane properties and pervaporation separation was discussed. Attenuated total reflection Fourier transform infrared spectroscopy confirmed the formation of a polyurea layer on mPAN. Field emission scanning electron microscopy and surface water contact angle analysis indicated no change in the membrane morphology and hydrophilicity, respectively, despite the addition of cosolvents for interfacial polymerization. The TFC membrane produced when ethanol was the cosolvent exhibited the highest separation performance (permeation flux = 1006 ± 103 g·m−2·h−1; water concentration in permeate = 98.8 ± 0.3 wt.%) for an aqueous feed solution containing 90 wt.% THF at 25 °C. During the membrane formation, ethanol caused the polyurea layer to loosen and to acquire a certain degree of cross-linking. The optimal fabrication conditions were as follows: 10 wt.% ethanol as cosolvent; membrane curing temperature = 50 °C; membrane curing time = 30 min.

Core-shell structured polyethylene glycol functionalized graphene for energy-storage polymer dielectrics: Combined mechanical and dielectric performances

Polydispersed graphene was synthesized by grafting a thin layer of water-soluble amine functionalized polyethylene glycol monomethyl ether (PEG-NH2). PEG-NH2 functionalized graphene (PEG@rGO) was then introduced into epoxy resin via a facile solution mixing method. Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) verified that PEG was successfully grafted to the surface of graphene. The obtained PEG@rGO showed excellent dispersibility in solvents when compared to pristine graphene. As a “core-shell” filler, PEG@rGO filled epoxy nanocomposites displayed improved dielectric constant and reduced dielectric loss, exhibiting potential applications in energy storage capacitors. The mechanical strength and final decomposition temperature were also simultaneously increased.

TAAR Agonists.

Trace amine-associated receptors (TAARs) are a family of G protein-coupled receptors (GPCRs) that are evolutionarily conserved in vertebrates. The first discovered TAAR1 is mainly expressed in the brain, and is able to detect low abundant trace amines. TAAR1 is also activated by several synthetic compounds and psychostimulant drugs like amphetamine. Activation of TAAR1 by specific agonists can regulate the classical monoaminergic systems in the brain. Further studies have revealed that other TAAR family members are highly expressed in the olfactory system which are termed olfactory TAARs. In vertebrates, olfactory TAARs can specifically recognize volatile or water-soluble amines. Some of these TAAR agonists are produced by decarboxylation of amino acids. In addition, some TAAR agonists are ethological odors that mediate animal innate behaviors. In this study, we provide a comprehensive review of TAAR agonists, including their structures, biosynthesis pathways, and functions.

Use of cobalt(II) chelates of monothiol-containing ligands for the removal of nitric oxide.

It is first reported herein that cobalt(II) complexes solution of monothiol-containing multidentate ligands are used to remove low concentration of nitric oxide (NO). These chelating ligands are water-soluble amines, alcohols or acids which containing at least one -SH group, include those of cysteine, mercaptosuccinic acid, mercaptoethanesulfonate, mercaptopropionic acid and the like. These -SH compounds when coordinated with cobalt ions, forming complexes are very effective for NO removal. The results indicate that the side group (methyl, carboxyl, carboxymethyl) on α-carbon atom of ligands contribute to the denitration of the chelate solution, whereas the substituents on sulfur atom of ligands deactivate the complexation system. In addition, we have found that several monothiol compounds with simple molecule structure and low cost exhibit good performance in denitration, and some of cobalt thiol complexes are more valuable in removing NO than ferrous thiol complexes.

Characterizing the Effects of a "Switchable Water" Additive on the Aqueous Solubility of Small Molecules.

"Switchable water" is an aqueous solution containing a water-soluble amine additive that exhibits CO2 -switchable properties, such as large changes in ionic strength, by forming an ammonium bicarbonate salt. Switchable water has been used to reversibly "salt-out" organic compounds from water. This study explores the salting out of several compounds in switchable water when CO2 is present and also explores the solubility of small molecules in switchable water, compared to pure water, when CO2 is absent. The results show that organic compounds are generally more soluble in switchable water than pure water in the absence of CO2 , but less soluble in the presence of 1 atm CO2 . Exceptions include carboxylic acids and phenols which, presumably due to their acidity, are more soluble in switchable water than in pure water, even when CO2 is applied. Kirkwood-Buff solvation theory was applied to gain insights into the effects of the amine additive on the aqueous solubility of caffeine. Furthermore, the switchable properties of the additives allow for the preparation of switchable aqueous two-phase systems.

CO2 adsorption using water-soluble polyaspartamide

Freeze-drying is one of the promising purification technologies due to its ability to produce outputs with high purity at low energy. This work attempts to improve the adsorption properties of a novel amine adsorbent for CO2 capture through the use of freeze drying process. Thus, a polyaspartamide (PAA) was produced after freeze-drying process of a polysuccinimide (PSI) synthesized through polycondensation reaction. The synthesized PSI was grafted with a monoethanolamine (MEA), a water-soluble amine, and an ethylenediamine (EDA), then tested for CO2 capture. The BET analysis showed the enhancement of geometry/structure with the increase of water-soluble amine (MEA) in the PAA. In addition, testing the CO2 adsorption capacity with pure CO2 at 1.1 bar and a temperature of 40 °C using a thermogravimetric analyser resulted in increase of CO2 adsorption capacity as the amount of MEA in PAA increased. The maximum CO2 adsorbed was 44 mg-CO2/g at 100% MEA incorporated in PAA, indicating a significant increase from 19 mg-CO2/g recorded for the crude PSI. Thus, the water soluble PAA could be an effective adsorbent for CO2 capture via adsorption technology for the reduction of CO2 emissions in future.

Multi-pollutant emissions from the burning of major agricultural residues in China and the related health-economic effects

Abstract. Multi-pollutants in smoke particulate matter (SPM) were identified and quantified for the biomass burning of five major agricultural residues (wheat, rice, corn, cotton, and soybean straw) in China by an aerosol chamber system combined with various measurement techniques. The primary emission factors (EFs) for PM1. 0 and PM2. 5 are 3.04–12.64 and 3.25–15.16 g kg−1. Organic carbon (OC), elemental carbon (EC), water-soluble inorganics (WSIs), water-soluble organic acids (WSOAs), water-soluble amine salts (WSAs), trace mineral elements (THMs), polycyclic aromatic hydrocarbons (PAHs), and phenols in smoke PM1. 0/PM2. 5 are 1.34–6.04/1.54–7.42, 0.58–2.08/0.61–2.18, 0.51–3.52/0.52–3.81, 0.13–0.64/0.14–0.77, (4.39–85.72/4.51–104.79) × 10−3, (11.8-51.1/14.0-131.6) × 10−3, (1.1–4.0/1.8–8.3) × 10−3, and (7.7–23.5/9.7–41.5) × 10−3 g kg−1, respectively. Black carbon (BC) mainly exists in PM1. 0; heavy-metal-bearing particles favour residing in the range of smoke PM1. 0−2. 5, which is also confirmed by individual particle analysis. With respect to the five scenarios of burning activities, the average emissions and overall propagation of uncertainties at the 95 % confidence interval (CI) of SPM from agricultural open burning in China in 2012 were estimated to be 1005.7 (−24.6, 33.7 %), 901.4 (−24.4, 33.5 %), 432.4 (−24.2, 33.5 %), 134.2 (−24., 34.0 %), 249.8 (−25.4, 34.9 %), 25.1 (−33.3, 41.4 %), 5.8 (−30.1, 38.5 %), 8.7 (−26.6, 35.6 %), 0.5 (−26.0, 34.9 %), and 2.7 (−26.1, 35.1 %) Gg for PM2. 5, PM1. 0, OC, EC, WSI, WSOA, WSA, THM, PAHs, and phenols , respectively. The emissions were further spatio-temporally characterized using a geographic information system (GIS) in different regions in the summer and autumn post-harvest periods. It was found that less than 25 % of the total emissions were released during the summer harvest, which was mainly contributed by the North Plain and the centre of China, especially Henan, Shandong, and Anhui, which are the top three provinces regarding smoke particle emissions. Flux concentrations of primarily emitted smoke PM2. 5 that were calculated using the box-model method based on five versions of emission inventories all exceed the carcinogenic-risk permissible exposure limits (PEL). The health impacts and health-related economic losses from the smoke PM2. 5 short-term exposure were assessed. The results show that China suffered from 7836 cases (95,% CI: 3232, 12362) of premature mortality and 7 267 237 cases (95 % CI: 2 961 487, 1 130 784) of chronic bronchitis in 2012, which led to losses of USD 8822.4 million (95 % CI: 3574.4, 13 034.2) or 0.1 % of the total GDP. We suggest that the percentage of open-burnt crop straw in the post-harvest period should be cut down by over 97 % to ensure a reduction in carcinogenicity risk, especially in the North Plain and the northeast, where the emissions should decrease at least by 94 % to meet the PEL. With such emission control, over 92 % of the mortality and morbidity attributed to agricultural fire smoke PM2. 5 can be avoided in China.

MODIFICATION OF EPOXY-AMINE POLYMERS BY OLIGOHEXAMETHYLENEGUANIDINES

Methods of introducing a water-soluble biocide modifier, oligohexamethyleneguanidine hydrochloride, into epoxy-amine systems were studied. The obvious way is the introduction of the modifier in the waterborne epoxy-amine systems. However, this leads to cured systems with reduced mechanical properties. Introduction of oligohexamethyleneguanidine hydrochloride solutions in organic solvents into epoxy-amine systems allows obtaining a homogeneous system, but their application is limited by the presence of a volatile solvent. Finally, introduction of oligohexamethyleneguanidine hydrochloride solutions in a water-soluble amine curing agent into epoxy-amine systems has good prospects. It is shown that the analyzed modifier has good solubility in ethylenediamine, but poor solubility in oligooxypropylenediamine. It was found that the modifier is capable of interacting chemically with epoxy resins at 22°C to form an elastic insoluble material. In an epoxy-amine system with a more active hardener (ethylenediamine) oligohexamethyleneguanidine hydrochloride acts as a plastifier (flexibilizer). This significantly reduces the glass transition temperature of the matrix (from 53 to 37ºC).

Meldonium

Meldonium

Dip 추출에서 유체 표면의 영향을 고려한 친환경 포토레지스트 박리공정

This paper describes a green stripping process to effectively strip the remaining DFR layer on a non-alkali-based ITO glass surface after an etching process. A stripper, water-soluble amine compound, is used to investigate the characteristics of stripping ability and to suggest a valid method for the green process. Increasing the composition (5-30% concentration) of the ethanol amine-based stripper was found to greatly reduce the stripping time applied in the dipping method. The composition (30%) achieved an excellent stripping effect and free-residue impurities. Additionally, it was possible to obtain the effect of stripping in a way to sustain the release before generating DFR sludge from the ITO glass surface by using dipping condition (stripping time) in the composition. An Additional stripping process (buffering) out of dipping can realize productivity improvement and cost reduction because of the higher proportion of re-use of the stripping solution used in the DFR removal step.

Effect of the Presence of Water-soluble Amines on the Carbon Dioxide (CO2) Adsorption Capacity of Amine-grafted Poly-succinimide (PSI) Adsorbent During CO2 Capture

Global climate change is among the major challenges the world is facing today, and can be attributed to enhanced concentrations of Greenhouse Gases (GHG), such as carbon dioxide (CO2), in the atmosphere. Therefore, there is an urgent need to mitigate CO2 emissions, and carbon capture and storage (CCS) is amongst the possible options to reduce CO2 emission. Against this background, this work investigated the synthesis and performance evaluation of a new material for CO2 capture. In particular, the effect of the presence of water-soluble amines in the amine-grafted poly-succinimide (PSI) (referred to as Polyaspartamide (PAA) adsorbent), was investigated. Methyl Amine (MA) and Mono-Ethanol Amine (MEA) were employed as water-soluble amines and the effect of changes in their concentration on CO2 adsorption capacity was investigated as well. Water-soluble amines were incorporated to allow water solubility of the adsorbent paving way for freeze-drying to improve the geometric structure (surface area, pore volume and pore size) of the adsorbent. The water-soluble amines were grafted to an already Ethylenediamine (EDA) grafted PSI (PSI-EDA), with the EDA added to improve the chemical surface of the adsorbent for CO2 capture. The NMR analysis confirmed the presence of MA and MEA amine groups in the PAA, thereby indicating the presence of the grafted amines on the backbone polymer. An increase in adsorption capacity with an increase in MA and MEA concentrations in MA-PAA and MEA-PAA samples was observed. At low amine concentrations (20% amine and 80% EDA grafted), MEA-PAA was observed to exhibit higher adsorption capacity compared to the MA-PAA samples. At high amine (100% amine grafted) concentrations, MA-PAA samples displayed higher adsorption capacity. Three runs were performed on each sample and the results obtained were reproducible. The best adsorption capacity obtained was 44.2g CO2/kg Ads. However, the operating conditions during the CO2 adsorption should be optimized for enhanced CO2 adsorption capacity.

Aqueous radical polymerization of N,N-dimethylacrylamide redox-initiated by aerobically catalytic oxidation of water-soluble tertiary amines

Catalytic oxidation of water-soluble tertiary amines by complexes of CuII, FeIII and CoII was utilized to initiate radical polymerization of N,N-dimethylacrylamide (DMAAm) in aqueous solution at 70–80 °C. The oxidation of tertiary amines by CuII was studied by proton nuclear magnetic resonance spectroscopy and online ultraviolet–visible spectrophotometry. The polymerization kinetics was monitored by gas chromatography, and molecular weight of the PDMAAm was measured by gel-permeation chromatography coupled with multi-angle laser light scattering. Oxidation of tertiary amines occurs predominantly via formation of Calpha·radicals to initiate polymerization of electron-deficient monomers and N-dealkylation, and redox equilibrium between CuI/L and CuII/L is established at a faster rate in aqueous media. FeIII and CuII complexes are efficient catalysts as each catalyst molecule could generate above 10 propagating radicals in 5 h, while CoII complex might involve in oxidation of tertiary amines in non-radical pathway, leading to a low catalytic efficiency. Water-soluble tertiary amines such as N,N-dialkylethanolamine (alkyl = methyl, ethyl etc.) are reducing agents of a higher activity in aqueous media than those primary or secondary analogues. Our strategy renders it possible to prepare polymer of alpha-amino functionality via one-pot process from commercially available commodity reagents under practical conditions with negligible catalyst residue.

Effect of Nano-Encapsulated Corrosion Inhibitors on Self-Healing Corrosion Protection of Steel Sheets

A nano-encapsulation system of organic corrosion inhibitors has been designed, which is capable of improving the self-healing corrosion protection without degrading the barrier protection of the coating layers. Core-shell nanoparticles loaded with six types of amine corrosion inhibitors such as ethanolamine, 5-amino-1-pentanol, diethanolamine, triethanolamine, propylamine and dipropylamine, were synthesized by multi-stage emulsion polymerization. Amines were successfully encapsulated into nanocapsules by reacting with carboxylic acid in core and shell polymer during alkalization swelling process. Water-soluble amines were effectively introduced in nanocapsules, and the basicity was the most predominant parameter for amine encapsulation. In alkaline condition, the encapsulated amines were generally well released and the release of the encapsulated amines was pH dependent regardless of the exposure time. In addition, the molecular structure and aqueous solubility were critical factors in the release behaviors. Linear amines and highly water-soluble amines were more easily released to the environments from inside capsules than branched and water-insoluble ones. The nanocapsules were incorporated into the coating resin and were coated on cold-rolled steel sheets to investigate corrosion protection efficiencies. The corrosion inhibitive efficiencies of the nanocapsule-containing coating layers were evaluated by semi-immersion tests and electrochemical tests, electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET). The organic coatings with inhibitor-loading nanocapsules showed better corrosion performance than the organic coating with inhibitor-free nanocapsules. Among six amines used in this study, 5-amino-1-pentanol, diethanolamine and triethanolamine exhibited self-healing anti-corrosion performance with recovering coating resistance. The coating resistance of the coating film gradually decreased and then increased via the self-healing corrosion protection of amines release from the nanocapsules. On the other hand, ethanolamine, propylamine and dipropylamine exhibited a rapid drop in the coating resistance, and the resistance continued to decrease without self-recovery. The inhibition efficiencies of encapsulated amines were affected by both intrinsic inhibition activities of amine and encapsulation/release behaviors.

RAFT-polymerized poly(hexafluoroisopropyl methacrylate)s as precursors for functional water-soluble polymers

Post-polymerization modification of well-defined precursor polymers is a versatile tool to obtain multifunctional water-soluble polymers that cannot be synthesized by common polymerization techniques. For the first time, 1,1,1,3,3,3-hexafluoroisopropyl methacrylate (HFIPMA) based homo and block copolymers were synthesized via RAFT polymerization to provide precise precursors for the post-polymerization modification of the 1,1,1,3,3,3-hexafluoroisopropyl ester side chains with water-soluble amines (methoxy tri(ethylene glycol) amine, 2-hydroxypropyl amine and 3-(dimethylamino)-1-propylamine). Sequential aminolysis using Oregon Green cadaverine first followed by 2-hydroxypropyl amine enables access to dye-labelled poly(2-hydroxypropyl methacrylamide) and aminolysis with 3-(dimethylamino)-1-propylamine provides homo and block co-catiomers that complex pDNA in PBS. To this respect, poly(1,1,1,3,3,3-hexafluoroisopropyl methacrylate)s P(HFIPMA)s as precursor polymers may become an alternative route for the synthesis of multifunctional water-soluble polymers for advanced applications.