Biobased step-growth polymers in powder coating applications

Co- and terpolyesters based on 1,4:3,6-dianhydro-d-glucitol (isosorbide), 1,4:3,6-dianhydro-l-iditol (isoidide) and succinic acid were evaluated for their applicability in solvent-cast and powder coatings. These biobased polyesters have functionalities and T_g values in the appropriate range for such applications and were cross-linked using conventional curing agents. Introduction of poly-functional monomers such as glycerol and citric acid led to coatings with enhanced performance with respect to mechanical and chemical resistance, compared to formulations based on linear polymers. The curing behavior of these systems was investigated with DSC and rheological experiments. Formulations containing citric acid-modified polyester resins showed rapid curing, probably facilitated by anhydride formation at the chain ends. Hydroxy- as well as carboxylic acid-functional 1,4:3,6-dianhydrohexitol-based polyesters proved to be suitable materials for coating applications with respect to solvent resistance, impact resistance and hardness, with performance comparable to commercially available systems. Accelerated weathering experiments showed that functional groups such as hydroxyl groups, carboxylic acids, anhydrides and peroxides are formed during UV-exposure. The weathered coatings have reduced impact stability. On the other hand, the appearance of the coatings does not change significantly. Isosorbide-based coating systems appear to have similar weathering resistance as conventional terephthalic acid-based poly(ester urethane) coatings.     

Isosorbide mono- and di-alkyl ethers,a new class of sustainable coalescents for water-borne paints

The performances of new biosourced solvents, the short mono- and di-alkyl isosorbide ethers have been assessed and compared with benchmark coalescents, namely Texanol and DBE-IB. Firstly, the influence of various coalescents and co-solvents on the glass transition temperature and viscosity of a styrene acrylic latex, Craymul 2423, has been determined. In a second time, application tests and MS-DWS (multispeckle diffusing wave spectroscopy) have been performed on a formulated paint to determine the kinetics of film formation and the quality of the coating. Moreover, this technique allows characterizing the coalescent influence on the water-borne paint drying kinetics. Particular attention has been paid to the influence of coalescent on the “open time” of the water-borne paint. At the same time, the quality of the coalesced film has been quantified by image analysis of the film crackles. Dialkyl isosorbide ethers, such as DMI and DEI (respectively dimethyl- and diethyl-isosorbide ether), show good coalescing properties at room temperature, while monomethylisosorbide (MMI) appears to act as a mere co-solvent. DMI exhibits a unique balance affinity for the aqueous dispersing phase and for the latex particles. It acts as a co-solvent during the water loss phase and as a coalescing agent during the film formation.     

Synthesis and Characterization of Soyamide Ferulate

Ferulic acid (4-hydroxy-3-methoxycinnamic acid) is a phytochemical antioxidant that is widely distributed throughout the plant kingdom. Cinnamic acid derivatives are used as biobased ultraviolet (UV) absorbers in sunscreen formulations. Soybean oil ferulate, a biobased UV absorber, was synthesized by reacting soyamide with ferulic acid. The resulting product was characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy, and gel permeation chromatography (GPC). Spectroscopic studies measured the soyamide-based ferulate maximum absorbance at 327 nm with a molar extinction coefficient of 19,705 L mol⁻¹ cm⁻¹. Soyamide ferulate has potential to be used in coatings.     

环糊精及其衍生物在药剂学上的应用

环糊精是通过与其包合来改善药物的性质的。本文综述了近年来环糊精及其衍生物在药剂上的应用 ,包括增加脂溶性药物的溶解度 ,提高药物稳定性 ,使液体药物固体化 ,作为药物的吸收促进剂 ,作为速、缓释制剂的载体 ,作为多肽、蛋白类药物的载体和靶向制剂的载体等。     

Bitumen fluxing properties of a new class of sustainable solvents: The isosorbide di-alkyl ethers

The performances of new bio-sourced solvents, the short chain mono- and di-alkyl isosorbide ethers, have been determined and compared to benchmark bitumen fluxes. The influences of fluxes and temperature on the Newtonian viscosity have been assessed. The various fluxes appear to impact also on the visco-elastic behaviour of paving bitumen and dimethyl isosorbide ether (DMI) exhibits good fluxing properties. This bio-sourced solvent has also the property to be fully miscible with water. The bitumen hardness recovery can consequently occur from two different phenomena: evaporation and diffusion from the bitumen to water, making this solvent an appropriate bitumen flux for rainy seasons.     

Sulfoxylated methyl esters as potential components of liquid formulations

Sulfoxylated methyl esters (Φ-MES) are obtained via sulfoxidation of fatty acid methyl esters with SO₂, O₂, and ultraviolet light of appropriate wavelength. These products may be used as co-surfactants with linear alkylbenzene sulfonate and alkyl ether sulfate, either in heavy-duty or in hand dishwashing liquids. Standard hand dishwashing formulations based on Φ-MESC₁₆ are presented and discussed with regard to solubility, viscosity, performance, and skin compatibility. The experimental results obtained indicate that the above-mentioned products can be regarded as potential components for liquid formulations.     

Synthesis of Crosslinked Chitosan with Epichlorohydrin Possessing Two Novel Polymeric Ligands and Its Use in Metal Removal

One of the major applications of chitosan and its derivatives is based on its ability to bind strongly toxic metal ions. In this work, two novel polymeric ligands were synthesized to investigate the adsorption properties of Cu(II), Pb(II), Zn(II) and Ni(II) ions in an aqueous solution. To prevent the reaction between as the C₂ amine group of chitosan and ECH, the C₂ amine group was protected N-benzylidene chitosan (CTB). After the reaction with ECH to give N-benzaldehyde crosslinked chitosan (CCTB), the Schiff base was removed in a dilute ethanol hydrochloride solution to obtain CCTS which has free amine group. CCTS–ECH was synthesized by the reaction of CCTS and ECH. Then, CCTS–ECH was reacted with (2-hydroxyphenylimino)methylbenzene-1,4-diol (HBD) and N,N′-bis(2,5-dihydroxybenzylidene)-1,4-diaminobenzene (DHDB) to give ligands CCTS–ECH–HBD and CCTS–ECH–DHDB. The batch experiments showed that two novel polymeric ligands can be effectively used to remove Cu(II) from water.     

Vinyl methyl oxazolidinone as reactive diluent to overcome the solubility limitations of highly polar unsaturated polyesters

Vinyl methyl oxazolidinone (VMOX®) is studied as a new reactive diluent (RD) for highly polar unsaturated polyesters (UPs). Molecules with special structure properties are extensively investigated as components for unsaturated polyester resins (UPRs) and thermosets, particularly for high-temperature applications. Special diols with a cyclic structure like isosorbide and tricyclodecanedimethanol or special diols with side groups like 2-methyl-2-propyl-1,3-propanediol and 2-ethyl-2-butyl-1,3-propanediol can provide interesting properties. Bio-based diols such as isosorbide and 1,3-butanediol improve the sustainability profile. However, UPs based on such special diols have a higher polarity, limiting their solubility in styrene. This demands a RD, which provides adequate solubility and is suitable for high-temperature applications. Therefore, our study compares the solubility of highly polar UPs based on special diols in styrene and VMOX®. UPs with different formulations, polarities, and Hansen parameters were synthesized and characterized. The solubility sphere of styrene was determined experimentally with the synthesized UPs. The influence of the special diols on the thermoset properties was investigated in dynamic mechanical analysis measurements. In conclusion, VMOX® as a RD enables full utilization of special diols properties due to the wide solubility window. Moreover, a new class of high-temperature styrene-free UP resin was developed.     

Two-component high-solid polyurethane coating systems based on soy polyols

Soybean oil based polyols—soybean oil phosphate ester polyols (SOPEPs)—having varying hydroxyl content and viscosity were prepared as low cost and low-VOC polyols for coatings applications. These SOPEPs were used as the hydroxyl component of “two-component polyurethane (2K-PU)” coating compositions and their film properties were studied. Blends of commercial polyester polyol and SOPEP in varying proportions were also used to formulate PU coatings. Their film properties were studied and compared. We found that SOPEP can be used as the sole hydroxyl component or as the reactive diluent for polyester polyols in 2K-PU coating systems. SOPEP, is derived from a relatively inexpensive and renewable resource and the use of SOPEP can substantially reduce VOC and cost of PU coating formulations. Presented at the International Waterborne, High-Solids, and Powder Coatings Symposium, New Orleans, LA, February 2002.     

Formulation of ultralow interfacial tension systems using extended surfactants

Inspired by the concept of lipophilic and hydrophilic linkers, extended surfactants have been proposed as highly desirable candidates for the formulation of microemulsions with high solubilization capacity and ultralow interfacial tension (IFT), especially for triglyceride oils. The defining characteristic of an extended surfactant is the presence of one or more intermediate-polarity groups between the hydrophilic head and the hydrophobic tail. Currently only limited information exists on extended surfactants; such knowledge is especially relevant for cleaning and separation applications where the cost of the surfactant and environmental regulations prohibit the use of concentrated surfactant solutions. In this work, we examine surfactant formulations for a wide range of oils using dilute solutions of the extended surfactant classes sodium alkyl polypropyleneoxide sulfate (R-(PO) _x −SO₄Na), and sodium alkyl polypropyleneoxide-polyethyleneoxide sulfate (R-(PO) _y -(EO) _z −SO₄Na). The IFT of these systems was measured as a function of electrolyte and surfactant concentration for polar and nonpolar oils. The results show that these extended surfactant systems have low critical micelle concentrations (CMC) and critical microemulsion concentrations (CμC) compared with other surfactants. We also found that the unique structure of these extended surfactants allows them to achieve ultralow IFT with a wide range of oils, including highly hydrophobic oils (e.g., hexadecane), triolein, and vegetable oils, using only ppm levels of these extended surfactants. It was also found that the introduction of additional PO and EO groups in the extended surfactant yielded lower IFT and lower optimum salinity, both of which are desirable in most formulations. Based on the optimum formulation conditions, it was found that the triolein sample used in these experiments behaved as a very polar oil, and all other vegetable oils displayed very hydrophobic behavior. This unexpected triolein behavior is suspected to be due to uncharacterized impurities in the triolein sample, and will be further evaluated in future research.     

“Acid” pyrolysis-capillary chromatographic analysis of anionic and nonionic surfactants

A tandem “acid” pyrolysis-capillary chromatographic method for analyzing surfactants has been developed, and its application to the more common anionic and nonionic surfactant types investigated. In this method a surfactant is mixed with an acid, such as P₂O₅ or H₃PO₄, and dropped into a pyrolyzer attached to a capillary gas chromatograph. The resulting volatile pyrolyzate is carried into the chromatograph for analysis. According to the chromatograms, the point of cleavage during “acid” pyrolysis is quite selective, usually at a C-S or C-O bond. For example, LAS and ABS give peaks corresponding to the alkylbenzene precursors; primary linear alkyl sulfates and sulfonates, peaks corresponding to olefins with the same number of carbon atoms as the alkyl group; and alcohol and alkylphenol ethoxylates and ethoxylate sulfates, peaks corresponding to olefins from the alkyl group and to acetaldehyde and a higher aldehyde from the polyethoxy group. Alkylphenol derivatives are probably cleaved to form an alkylphenoxy intermediate, which then dealkylates to give the olefins. This method is quantitative for carbon number or carbon number and isomer distribution of hydrophobes in linear surfactants, semiquantitative for ethoxy content and for hydrophobes in branched chain surfactants, and qualitative for hydrotropes and certain foam additives. Surfactants, as well as mixtures of certain surfactant types, in built detergent formulations can be analyzed without isolation. Winner, Bond Award Medal, Philadelphia, October 1966.     

Combination of TLC Blotting and Gas Chromatography–Mass Spectrometry for Analysis of Peroxidized Cholesterol

We have established a sensitive and convenient method for analysis of cholesterol hydroperoxides (Chol-OOHs) as trimethylsilyloxyl derivatives using diphenylpyrenylphosphine (DPPP)-thin-layer chromatography (TLC) blotting and gas chromatography–electron ionization–mass spectrometry/selected-ion monitoring (GC–EI–MS/SIM). Chol-OOH standards were prepared by photosensitized oxidation and azo radical-induced peroxidation of cholesterol. Trimethylsilyloxyl derivatives of cholesterol 5α-hydroperoxide (Chol 5α-OOH), cholesterol 7α-hydroperoxide (Chol 7α-OOH), and cholesterol 7β-hydroperoxide (Chol 7β-OOH) could be separated from one another in the SIM chromatogram using a fragment ion with elimination of trimethylsilanol from the molecular ion. This method was used to characterize peroxidized cholesterol from azo radical-exposed human low-density lipoprotein and UVA-irradiated human keratinocytes in the presence of hematoporphyrin. Finally, we succeeded in the quantification of each Chol-OOH isomer present in hairless mouse skin with and without UVA irradiation by use of β-sitosterol hydroperoxide as internal standard. The accumulation of Chol 5α-OOH with Chol 7α/βOOH in the skin indicates that singlet molecular oxygen (¹O₂) participated in the peroxidation of skin cholesterol, because Chol 5α-OOH is known to be a ¹O₂ specific cholesterol peroxidation product. We concluded that the combination of DPPP-TLC blotting and GC–EI–MS/SIM is useful for quantifying peroxidized cholesterol in biological samples and confirming the participation of ¹O₂ in oxidative stress.     

Synthesis and characterization of telechelic macromers containing fatty acid derivatives

Telechelic macromers end-capped with (meth)acrylic functionalities are the most commonly used materials in rigid, dental formulations. In order to provide higher flexibility to the final product (not necessarily for dental applications), long chain aliphatic fatty acid derivatives may be chosen. Thus, new telechelic macromers comprising methacrylic functionalities and dimer fatty acid derivatives have been synthesized for the first time, and their chemical structure is discussed in detail. Six different systems comprising ester, anhydride and urethane bonds were synthesized from non-toxic raw materials. FTIR spectroscopy and NMR analysis were used to evaluate chemical structure of new systems. Their molecular masses were estimated from GPC measurements and from an analytical method based on iodine value determination. The latter one proved to be very accurate in determining molecular masses of methacrylated telechelics according to a new method developed in this work. We demonstrated that, via simple organic chemistry, different architectures of telechelic macromers comprising commercially available, long chain derivatives of fatty acid, mainly linoleic acid, with α,ω-dihydroxy, α,ω-dicarboxy or α,ω-diamino functionalities were successfully synthesized. These macromers facilitate the development of new reactive (preferably, photocurable) flexible systems for potential biomedical applications.     

Biobased isosorbide methacrylate monomer as an alternative to bisphenol A glycerolate dimethacrylate for dental restorative applications

In this study, a new biobased isosorbide urethane methacrylic monomer [isosorbide‐derived urethane dimethacrylate (Is‐UDMA)] was evaluated as a replacement for currently used bisphenol A glycerolate dimethacrylate (Bis‐GMA) based dental restorative materials. Dental composites were prepared at different Is‐UDMA and Bis‐GMA concentrations. For these composites, the photocuring kinetics, volumetric shrinkage, viscoelastic properties, water sorption, and solubility were evaluated. The photocuring kinetics, followed by real‐time IR spectroscopy, showed higher double‐bond conversion (DC) values for the formulations containing the Is‐UDMA monomer; the highest DC (82%) was achieved by the formulation prepared with only the Is‐UDMA monomer. The volumetric shrinkage was reduced to 23.7% as compared with the dental resin formulated with Bis‐GMA. The viscoelastic properties of the formulations containing both Is‐UDMA and Bis‐GMA monomers in a 50:50 composition were superior to the rest of the tested formulations, including those prepared with pure polymers. This behavior was explained in terms of a compromise between crosslinking and rigidity (or flexibility) of the resulting polymer network. A preliminary test on microleakage in a dental enamel demonstrated that the new Is‐UDMA monomer is a potential replacement for the Bis‐GMA monomer in dental restorative materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44591.     

Polymers with shape memory effect from renewable resources: crosslinking of polyesters based on isosorbide,itaconic acid and succinic acid

Polycondensation of isosorbide with itaconic acid and succinic acid was performed in the presence of sulfuric acid as a catalyst in toluene around 140 °C under microwave irradiation. Molar ratios of itaconic acid were varied to investigate the influence of itaconic acid on molecular weights and glass transition temperatures. For polyesters of isosorbide, itaconic acid and succinic acid T_g values were found from 57 °C to 65 °C. The molecular weights obtained varied from 1200 Da for poly(isosorbide itaconate) UPE100 up to 3500 Da for poly(isosorbide succinate) UPE0. The copolyesters obtained were crosslinked radically with dimethyl itaconate giving a round shaped material with slightly raised T_g values up to 74 °C. Furthermore, with dimethyl itaconate crosslinked copolyesters showed a one‐way shape memory effect upon heating after deformation at the glass transition temperature. © 2013 Society of Chemical Industry     

Microwave-assisted synthesis of carboxymethylcellulose – based polymeric surfactants

Summary Carboxymethylcellulose (CMC, DS_CM = 1) was partially hydrophobized in order to prepare polymeric surfactants by the transesterification reaction using the methyl ester of the fatty acid complex of rapeseed oil (MERO). The chemical modification was performed in different reaction media (i) DMF/TSA and (ii) H₂O/DMF with and without K₂CO₃ as catalyst, at various reaction conditions and using microwave radiation with controlled power as heating source. The obtained MERO-hydrophobized CMC (MH-CMC) comprising mixed fatty acyl esters were characterized by FT-IR and NMR spectroscopic techniques, which indicated a very low degree of esterification (DS < 0.1). The derivatives showed, in spite of moderate surface tension-lowering effects, excellent emulsifying activity for ‘oil in water’ type emulsions as well as good performance properties including washing power and antiredeposition efficiency. The results suggested that surface-active MH-CMC derivatives can be prepared under microwave heating at reaction times in the range of several minutes, what is a great advantage in comparison to transesterification reactions lasting up to 6 h at conventional heating. The novel CMC esters represent biodegradable polymeric surfactants with potential applications in manufacture of consumer products and in industrial processes.     

The combustion behavior of epoxy-based multifunctional electrolytes

Multifunctional or structural electrolytes are characterized by ionic conductivity high enough to be used in the electrochemical devices and mechanical performance suitable for the structural applications. Preliminary insights are provided into the combustion behavior of structural bi-continuous electrolytes based on bisphenol A diglycidyl ether (DGEBA), synthesized using the techniques of reaction induced phase separation and emulsion templating. The effect of the composition of the structural electrolytes and external heat flux on the behavior of the formulations were studied using a cone calorimeter with gases formed during testing analyzed using FTIR. The composition of the formulations investigated was changed by varying the type and amount of the ion conductive part of the bi-continuous electrolyte. Two ionic liquids, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIM-TFSI) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF₄), as well as a deep eutectic solvent (DES) based on ethylene glycol and choline chloride, were used. The results obtained confirm that time to ignition, heat release rate (HRR), total mass loss, as well as the composition of the gases released during tests depend on the composition of the formulations. Addition of liquid electrolyte is found to reduce the time to ignition by up to 10% and the burning time by between 28% and 60% with the added benefit of reducing the HRR by at least 34%. Gaseous products such as CO₂, CO, H₂O, CH₄, C₂H₂, N₂O, NO, and HCN were detected for all formulations with the gases SO₂, NH₃, HCl, C₂H₄, and NH₃ found to be for certain formulations only.     

Coenzyme Q10: Novel Formulations and Medical Trends

The aim of this review is to shed light over the most recent advances in Coenzyme Q₁₀ (CoQ₁₀) applications as well as to provide detailed information about the functions of this versatile molecule, which have proven to be of great interest in the medical field. Traditionally, CoQ₁₀ clinical use was based on its antioxidant properties; however, a wide range of highly interesting alternative functions have recently been discovered. In this line, CoQ₁₀ has shown pain-alleviating properties in fibromyalgia patients, a membrane-stabilizing function, immune system enhancing ability, or a fundamental role for insulin sensitivity, apart from potentially beneficial properties for familial hypercholesterolemia patients. In brief, it shows a remarkable amount of functions in addition to those yet to be discovered. Despite its multiple therapeutic applications, CoQ₁₀ is not commonly prescribed as a drug because of its low oral bioavailability, which compromises its efficacy. Hence, several formulations have been developed to face such inconvenience. These were initially designed as lipid nanoparticles for CoQ₁₀ encapsulation and distribution through biological membranes and eventually evolved towards chemical modifications of the molecule to decrease its hydrophobicity. Some of the most promising formulations will also be discussed in this review.     

Enhanced fibroblast adhesion and proliferation on electrospun fibers obtained from poly(isosorbide succinate-b-l-lactide) block copolymers

Block copolymers containing isosorbide succinate and l-lactic acid repeating units with different mass compositions were synthesized in two steps: bulk ring-opening copolymerization from l-lactide and poli(isosorbide succinate) (PIS) preoligomer, in the presence of tin(II) 2-ethylhexanoate as catalyst, followed by chain extension in solution by using hexamethylene diisocyanate. Poly(l-lactide) (PLLA) and a chain extension product from PIS were also obtained, for comparison. SEC, ¹H and ¹³C NMR, MALDI-TOFMS, WAXD, DSC, TG, and contact angle measurements were used in their characterization. The incorporation of isosorbide succinate into PLLA main backbone had minor effect on the thermal stability and the T_g of the products. However, it reduced the crystallinity and increased the surface energy in relation to PLLA. Nonwoven mats of the block copolymers and PLLA obtained by electrospinning technique were submitted to fibroblasts 3T3-L1 cell culture. The copolymers presented enhanced cell adhesion and proliferation rate as revealed by MTT assay and SEM images.     

Multiphasic calcium orthophosphate (CaPO4) bioceramics and their biomedical applications

Due to the chemical similarity to the inorganic constituents of calcified tissues of mammals, biologically relevant calcium orthophosphates (CaPO₄) have been applied as artificial bioceramics suitable for reconstruction of various types of bone defects. Since none of the known individual types of CaPO₄ appears to be able to mimic both the composition and the properties of natural bones, various attempts have been sought to overcome this problem and a multiphasic (polyphasic) concept is one of the reasonable solutions. In general, this approach is determined by advantageous formulations consisting of homogeneous blends of two (biphasic), three (triphasic) or more (multiphasic) individual CaPO₄ phases possessing diverse solubility and, therefore, bioresorbability, while the optimum ratios among the phases depend on the definite applications. Therefore, all currently known multiphasic CaPO₄ formulations are sparingly soluble in water and, thus, after being implanted they are gradually resorbed inside the body, releasing calcium and orthophosphate ions into the biological medium and, hence, seeding a new bone formation. They have already demonstrated a proven biocompatibility, osteoconductivity, safety and predictability in vitro, in vivo, as well as in clinical trials. More recently, in vitro and in vivo studies have shown that some of them might possess osteoinductive properties. Hence, in tissue engineering, multiphasic CaPO₄ bioceramics represent promising formulations to construct various scaffolds capable of carrying and/or modulating the behavior of cells. This review summarizes the available information on biphasic, triphasic and multiphasic CaPO₄ bioceramics including their biomedical applications. New formulations have been proposed as well.