Copolymer Resin Research Articles

Kinetic Study of Non-Isothermal Decomposition of Copolymer Resin Derived from 2, 4-Dihydroxypropiophenone, 1, 5-Diaminonaphthalene and Formaldehyde

Abstract The copolymer 2,4-DHP-1,5-DANF have been integrated by the build up of 2,4-dihydroxypropiophenone, 1,5-diaminonaphthalene with formaldehyde within the sight of 2M hydrochloric acid as an impetus with 2:1:3 molar extent of responding monomers. The structure of copolymer has been clarified by different physico-concoction and otherworldly systems, for example, natural examination, UV-visible, FT-IR, 1H-NMR and non-watery conductometric titration. The warm deterioration example and its energy were examined by thermo gravimetric examination (TGA) in a static nitrogen environment at a warming rate of 10°C/min. The SW and FC strategies have been embraced to assess the energy and thermodynamics parameters, for example, the warm enactment vitality (Ea), request of response (n), entropy change (ΔS), energy change (ΔF), obvious entropy change (S*) and recurrence factor (Z). The order of disintegration response was found to 0.96.The energy of thermal activation dictated by these strategies are in close concurrence with one another.

Analysis of Catecholamine and Their Metabolites in Mice Brain by Liquid Chromatography-Mass Spectrometry Using Sulfonated Mixed-mode Copolymer Column.

In this study, a simultaneous assay for catecholamines and their metabolites in the brain was established using liquid chromatography-mass spectrometry (LC-MS). To achieve complete separation, a cation-exchange/reversed-phase mixed-mode copolymer resin column containing 0.81 wt% sulfo groups was used for the simultaneous LC-MS assay. The analyzed catecholamines were dopamine (DA), norepinephrine (NE), and epinephrine (E), while the metabolites lacking amino groups were 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG). The metabolites were separated and detected using LC-MS, on columns with and without sulfo groups. However, we could not achieve adequate separation of catecholamines on both columns using a gradient elution of 0 - 50 (v/v)% methanol containing 0.1 (v/v)% formic acid (FA). When volatile ion-pairing reagents were added to the mobile phase, they improved the retention and detection of catecholamines on the sulfonated mixed-mode column. Under optimized elution conditions, which involved a linear gradient elution of water containing 0.1 (v/v)% FA to 50 (v/v)% acetonitrile in 50 mM ammonium formate at 40°C and a 0.20 mL/min rate, all six target molecules were simultaneously detected within 25 min, when using negative mode LC-MS on a sulfonated mixed-mode column. The limits of detection (LODs) for DA, NE, E, DOPCA, HVA, and MHPG were determined to be 20.7, 12.6, 74.6, 1110, 18.7, and 3196 nM, respectively. Moreover, the established LC-MS assay allowed the detection of endogenous DA, NE, and HVA, in normal mouse brain samples at concentrations higher than 20, 9, and 4 pmol/mg, respectively.

Biodegradable copolymer-based composites made from straw fiber for biocomposite flowerpots application

Biodegradable copolymer-based composites produced from straw fiber (SF) with hydrolyzed soybean protein isolate/urea/formaldehyde (HSPI/U/F) copolymer-based adhesive for biocomposite flowerpots (BFP) application was presented in this work, and molecular structure, morphology, biodegradability and microbial population of the resulting materials were also investigated. FTIR and SEM results indicated that the copolymer resin have been successfully prepared. The prepared BFP showed good biodegradation, and the introduction of HSPI increased the degradation rate of BFP, which was nearly 50% at 24 months. After 30 days of controlled composting, the CO2 release accumulation of BFP could reach 24 g. During the process of BFP degradation, the number of bacteria and fungi on the surface was higher than that of actinomyces, indicating the bacteria and fungi selectively accumulated on the BFP composites surface to accelerate its degradation. At the same time, nitrate ion could also be formed by nitrobacteria, which promoted plant growth. There is no doubt that the obtained biodegradable copolymer possessed great potential for BFP application.

Synthesis of highly branched polymethylphenylsiloxane grafted epoxy resin copolymer for high efficiency ablation thermal protection coating

Highly branched polymethylphenylsiloxane grafted epoxy resin (HBPSE) was synthesized by grafting silicone intermediate onto epoxy resin via the condensation between methoxyl and hydroxyl. The chemical structure of the highly branched copolymer was characterized by FT-IR, 1H-NMR and GPC. The thermal stability of the HBPSE copolymer was characterized by TGA and muffle furnace ablation test. Furthermore, ablation thermal protection coating (ATPC) with HBPSE copolymer was prepared. Compared with classical epoxy based ATPC, the HBPSE based ATPC has better thermal stability and wider pyrolysis temperature range. After oxygen-acetylene test, the micromorphology and chemical composition of the HBPSE based ATPC were characterized by SEM, EDS and FT-IR. Finally, both the HBPSE based ATPC and epoxy based ATPC were assessed under the heat flow of 200 kW/m2 for 320 s, the ATPC with HBPSE matrix has a lower back face temperature and a better surface state.

New Binary Blends of Ethylene-co-n-butyl Acrylate (EBA) Copolymer and Low Molecular Weight Rosin Ester Resin with Potential as Pressure Sensitive Adhesives.

For improving the adhesion property of ethylene-co-n-butyl acrylate copolymer (EBA) at ambient temperature, binary blends of EBA with 27 wt% n-butyl acrylate and different amounts (20–62 wt%) of low molecular weight hydrogenated glycerol rosin ester (ECH) resin have been prepared. The addition of glycerol rosin ester resin decreased the crystallinity and size of the ethylene domains of the EBA copolymer. The addition of up to 50 wt% (100 phr) ECH resin improved the compatibility with the EBA copolymer, whereas when more than 50 wt% (100 phr) ECH resin was added, the compatibility of the blends did not change but the viscoelastic properties were noticeably decreased. Furthermore, the compatibility was noticeably improved by adding only 20 wt% ECH resin although the best compromise between compatibility and viscoelasticity corresponded to the binary blend made with 43 wt% ECH resin. The EBA copolymer + ECH resin blends showed high tack (initial adhesion) at 25 °C and some of them even at 5 °C, and they have adequate 180° peel strength both to polar (polyethylene terephthalate-PET) and nonpolar (polypropylene-PP) substrate. Furthermore, all EBA copolymer + ECH resin blends showed high shear strength at 25 °C. Finally, the blend with 43 wt% ECH resin showed excellent pressure sensitive adhesive property exhibiting excellent creep, high tack, high 180° peel strength, and high single lap-shear strength.

Green Preparation of Straw Fiber Reinforced Hydrolyzed Soy Protein Isolate/Urea/Formaldehyde Composites for Biocomposite Flower Pots Application.

The effects of soil burial on the biodegradation of biocomposite flower pots (BFP) made from straw fiber (SF) and hydrolyzed soy protein isolate/urea/formaldehyde (HSPI/U/F) copolymer resin were studied in detail. The microstructure, crystallinity, functional groups, mechanical, degradation and thermal property of the prepared SF with HSPI/U/F copolymer resin have been studied, and the degradation mechanism was also elucidated. XRD results showed that the bond breakage between SF and HSPI/U/F copolymer resin induced a decrease in relative degradation-resistant crystal structures. FTIR spectra showed that the methylolated HSPI units could form a cross-linking network with U/F and SF. The BFP degradation after soil burial was mainly attributed to the effects of microorganisms. The degradation products were environmentally friendly, because they were degradable and could fertilize the soil. In addition, the U/F adhesives were slightly degraded by the microorganisms due to the HSPI in the pots. The TG and DSC results showed that the molecular motion of the BFP matrix could be restricted by the degradation action and the content of HSPI, resulting in decreased crystallization enthalpy and showing good thermal property. The tensile strength of different reinforced samples was not significantly reduced in comparison to U/F resin, and still kept good mechanical performance. Thus, the prepared SF reinforced HSPI/U/F copolymer resins could have good potential for use in the field of biodegradable flower pots because of their good thermal property, mechanical property, biodegradability, and relatively low cost.

Preparation and luminescent properties of Eu(Ⅲ) organic complex and novel transparent ethylene-methyl acrylate copolymer (EMA) films doped with complexes

In this study, a new ternary rare earth organic complex Eu(POA)3TTA was synthesized and successfully doped into the ethylene-methyl acrylate copolymer (EMA) resins. The transparent doped EMA (Eu-EMA) films with excellent fluorescence performance were obtained by making full use of the excellent compatibility and filling performance of EMA resins. Fourier transform infrared spectrometer (FT-IR), elemental analysis, MALDI-TOF MS, scanning electron microscope (SEM), photoluminescence tests, thermogravimetric analysis (TGA) and static water contact angle measurements were used to characterize the properties of the complexes Eu(POA)3TTA and the Eu-EMA films. FT-IR analysis, elemental analysis and MALDI-TOF MS verify the ligands were successfully coordinated with the Eu3+ ions. The Eu(POA)3TTA particles are well dispersed in the EMA matrix and only a small fraction of them precipitate out to the surface of the EMA films. The relationship between fluorescence emission intensity of the Eu-EMA films and the doping ratios of Eu(POA)3TTA to EMA resins has been studied and discussed. The fluorescence intensity of the Eu-EMA films reaches the maximum when the doping ratio is 1.0 wt%. The Eu-EMA films all have high thermal stability (Td ≥ 392 °C) and the Td value enhances as the doping ratio increasing. As a result, the Eu-EMA films possess potential application for luminescent materials even at high temperatures.

Comparison of Antibacterial Activity of ZnO Nanoparticles Fabricated by Two Different Methods and Coated on Tetron Fabric

Background: Zinc Oxide Nanoparticles (ZnO NPs) have wide applications in various industries, especially they have been known for their antibacterial effects in polymers and textile fibers. ZnO NPs were produced by two different solutions and milling methods. Different techniques were used in order to select the most effective methods for coating the fabric with ZnO NPs. The microstructures and the composition of the ZnO NPs were investigated using Field Emission Scanning Electron Microscopy (FE-SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) and X-ray diffraction analysis (XRD). Additionally, the antibacterial activity of the treated fabric against Staphylococcus aureus and Escherichia coli bacteria was investigated. The overall experimental findings show that the highest inhibitory effect against Staphylococcus aureus in the sample of fabric which covered with ZnO NPs synthesized by the solution method. Methods: In the solution method, ZnO NPs were synthesized by dissolving zinc chloride in 1, 2 Ethanediol and mixing with aqueous solution of sodium hydroxide. In milling method, firstly, zinc sulfide nanoparticles were prepared through reaction between zinc acetate and Thioacetamide and then by milling and oxidation the zinc sulfide nanoparticles, ZnO NPs were synthesized. In order to deposition ZnO NPs on the Tetron fabric, it was fully drawn and fixed on a frame. After that, acrylic copolymer resin was added into distilled water and ZnO NPs were added in another beaker to ethanol. The two beakers were then placed in the ultrasonic bath for a certain time. Finally, the fabric was dipped into the beaker containing resin for some moment and then immersed into the beaker containing ZnO NPs. During these processes, both beakers were in the ultrasonic bath. After drawing out the fabric from second beaker, it was dried in air. This procedure was performed for both types of ZnO NPs fabricated by two mentioned methods. Antibacterial activity of ZnO NPs coated on the fabric against two types of bacteria was studied by agar diffusion method. Results: XRD patterns of synthesized powders from both methods were identified as ZnO NPs. Sharp diffraction peaks indicate good crystallinity of ZnO NPs. The morphology of the ZnO NPs fabricated by both methods which was analyzed by field emission SEM shows that the ZnO particles synthesized by milling and solution methods are in nano scale at the range of 26 - 29 nm and 9 - 11 nm, respectively. The highest inhibitory effect against Staphylococcus aureus was shown for the fabric which coated by ZnO NPs produced by the solution method. It was seen, the antibacterial activity of ZnO NPs fabricated by solution method was higher than that of milling method. Conclusion: ZnO NPs were synthesized by two different methods and the antibacterial activity of Tetron fabric coated with ZnO NPs was studied. Distribution and stability of ZnO NPs on the fabric depend on fabrication method and particle size which means that the smaller particles have more stability and better distribution than larger particles. The particle size and deposited concentration of ZnO NPs were effective on antibacterial activity, so that the smaller particles tend less agglomeration and have more surface area and because of that better antibacterial activity. Overall the results demonstrated a good antibacterial activity against Staphylococcus aureus than Escherichia coli.in the sample of fabric which covered with ZnO NPs synthesized by the solution method.

Rubber aggregate-cement matrix bond enhancement: Microstructural analysis, effect on transfer properties and on mechanical behaviours of the composite

Limited strain capacity and low tensile strength of cement-based materials make them brittle and sensitive to cracking, behavior that limits durability of cement-based applications. Rubber aggregates (RA) incorporation appeared to be a suitable solution to improve the strain capacity and to limit the propensity of such materials for cracking. However, bond defect between RA and cementitious matrix is well-known and detrimental to mechanical and transfer properties of rubberized cement-based composites. This paper is dedicated to the enhancement of rubber-cement matrix interface and then investigates effect of this bond on transfer properties and mechanical behaviors of rubberized mortars. To achieve this goal, RA were coated with styrene-butadiene copolymer and after densification of this copolymer resin on their surface, they were mixed with the premixed-cementitious mixture. Another approach implemented was the use of an air-detraining admixture to produce rubberized mixture with the similar air content as the control mortar. Microstructural studies firstly clarified that cement paste bonded firmly on copolymer-coated RA. Air-permeability of the rubberized mortar incorporating copolymer-coated RA was lower than that of the control mortar. Moreover, rubber coating approach was beneficial to reduce water capillary absorption and to limit reduction in direct tensile strength. It also results in a better residual post-peak behavior and higher fracture energy, contributing to improve the resistance of the composite to shrinkage cracking even under high restrained condition.

Multi-functional interface sensor with targeted IFSS enhancing, interface monitoring and self-healing of GF/EVA thermoplastic composites

Developing the fiber/matrix interface with combined structural and functional performances is of tremendous importance in ensuring the service safety of fiber reinforced plastic composites (FRPs) and expanding the capabilities of FRPs to perform multiple parallel tasks. Herein, a multi-functional interface sensor that can improve the interfacial shear strength, and simultaneously monitor and heal the interfacial damage between glass fiber yarn and thermoplastic ethylene-vinyl acetate copolymer resin (GF/EVA) is reported. The basic idea is introducing multi-walled carbon nanotube into GF/EVA interface. By this proposed method, the interfacial shear strength (IFSS) of GF/EVA composites is enhanced by 48.9%. The resistance of the interface sensor is recorded during the pull-out tests, and results show that the relative resistivity change could reflect the interfacial damage information very well. Electric heating of the sensor is adopted to heal the interfacial damage. The applied electrical power is discussed to evaluate the self-healing efficiency of the interfaces at different damage degrees. Successful interfacial self-healing ability is achieved and confirmed using different characterization techniques. Moreover, to verify the feasibility of our method in GF/EVA composite laminates, in-situ monitoring of the laminates under complicated stress and healing of delamination are performed. The results show that the developed sensor could monitor and heal the GF/EVA composite laminates with high sensing/healing ability. The proposed method and the obtained results could help to get a multi-functional sensor to ensure the service safety of composite structures.

Fabrication and Characterization of Graphene Microcrystal Prepared from Lignin Refined from Sugarcane Bagasse.

Graphene microcrystal (GMC) is a type of glassy carbon fabricated from lignin, in which the microcrystals of graphene are chemically bonded by sp3 carbon atoms, forming a glass-like microcrystal structure. The lignin is refined from sugarcane bagasse using an ethanol-based organosolv technique which is used for the fabrication of GMC by two technical schemes: The pyrolysis reaction of lignin in a tubular furnace at atmospheric pressure; and the hydrothermal carbonization (HTC) of lignin at lower temperature, followed by pyrolysis at higher temperature. The existence of graphene nanofragments in GMC is proven by Raman spectra and XRD patterns; the ratio of sp2 carbon atoms to sp3 carbon atoms is demonstrated by XPS spectra; and the microcrystal structure is observed in the high-resolution transmission electron microscope (HRTEM) images. Temperature and pressure have an important impact on the quality of GMC samples. With the elevation of temperature, the fraction of carbon increases, while the fraction of oxygen decreases, and the ratio of sp2 to sp3 carbon atoms increases. In contrast to the pyrolysis techniques, the HTC technique needs lower temperatures because of the high vapor pressure of water. In general, with the help of biorefinery, the biomass material, lignin, is found to be qualified and sustainable material for the manufacture of GMC. Lignin acts as a renewable substitute for the traditional raw materials of glassy carbon, copolymer resins of phenol formaldehyde, and furfuryl alcohol-phenol.

Sulfonated poly (styrene‐co‐ethylene glycol dimethacrylate) with attractive ion exchange capacity

Sulfonated resins are applied as catalysts in different reactions such as esterification, etherification, and transesterification. Poly (styrene‐co‐divinylbenzene) particles are the most used material for this kind of application. However, the development of copolymer resins with a longer crosslinker and more flexible chains could improve diffusion, mechanical, and chemical properties allowing the development of customized materials. In the present study, the use of ethylene glycol dimethacrylate, as crosslinker, was assessed in order to find optimal conditions to produce particles with high ion exchange capacity. The experimental study provided sulfonated styrene‐co‐(ethylene glycol dimethacrylate) with ion exchange capacities up to 5.98 meq/g. The present formulations provided resins with similar properties when compared with ion exchange capacity of commercially available products, such as Amberlyst® and Lewatit® resins. Furthermore, the present sulfonation process is energetically attractive because the reactions can be carried out at relatively low temperatures (approximately 58°C) and less reagent amounts in comparison with well‐known synthesis processes.

Microstructures, thermal and mechanical properties of epoxy asphalt binder modified by SBS containing various styrene-butadiene structures

As the most important thermoplastic and thermosetting modifiers, styrene–butadiene–styrene triblock copolymer (SBS) and epoxy resin have been widely applied in asphalt modifications. In this paper, epoxy SBS-modified asphalts (ESBAs) were prepared with epoxy monomer, curing agent and SBS-modified asphalts (SBAs) with various styrene–butadiene structures, which in turn were subjected to laser scanning confocal microscopy (LSCM), viscous measurements, thermal analysis and tensile tests. The LSCM results revealed that both polymer-rich phase and fluorescent particle-rich phase were observed in the asphalt matrix. Moreover, the number of SBS particles in SBAs increased with the increase of styrene contents. The presence of SBS decreased the size of dispersed domains in the continuous epoxy phase of the neat epoxy asphalt binder (EAB). For ESBAs, a double phase separation occurred between SBA and epoxy in the continuous epoxy phase and between asphalt and SBS in the dispersed SBA phase. Both number and size of SBS domains in the dispersed SBA phase of ESBAs increased with the increase of styrene contents. The inclusion of styrenic polymers increased the viscosity of the neat EAB. The viscosity of ESBAs increased with the increase of average molecular weights of the styrenic polymers. The addition of styrenic polymers increased the glass transition temperature (Tg) and storage modulus (E′) of the neat EAB. Meanwhile, the inclusion of styrenic polymers weakened the damping properties of the neat EAB. The styrene-butadiene structures had little effect on the Tg and damping properties of ESBAs. The E′ of ESBAs decreased with the increase of styrene contents. The presence of SBS enhanced the thermal stability of the neat EAB. Tensile results showed that the addition of SBS increased the tensile strength of the neat EAB.

The use of the vaccinia virus complement control protein (VCP) in the rat retina.

The complement system is highly implicated in both the prevalence and progression of Age-Related Macular Degeneration (AMD). Complement system inhibitors therefore have potential therapeutic value in managing excessive activation of the complement pathways in retinal degenerations. The vaccinia virus complement control protein (VCP) has been shown to be effective as a complement inhibitor in neuroinflammatory models including traumatic brain injury and spinal cord injury. We aimed to investigate the potential of VCP as a therapeutic molecule for retinal degenerations. In this study, we investigated the effect, localisation and delivery of VCP to the rodent retina. Complement inhibition activity of VCP was tested using a hemolytic assay. Photoreceptor cell death, inflammation and retinal stress were assayed to determine if any retinal toxicity was induced by an intravitreal injection of VCP. The effect of VCP was investigated in a model of photo-oxidative retinal degeneration. Localisation of VCP after injection was determined using a fluorescein-tagged form of VCP, as well as immunohistochemistry. Finally, a copolymer resin (Elvax) was trialled for the slow-release delivery of VCP to the retina. We found that a dose equivalent to 20μg VCP when intravitreally injected into the rat eye did not cause any photoreceptor cell death or immune cell recruitment, but led to an increase in GFAP. In photo-oxidative damaged retinas, there were no differences in photoreceptor loss, retinal stress (Gfap) and inflammation (Ccl2 and C3) between VCP and saline-injected groups; however, Jun expression was reduced in VCP-treated retinas. After VCP was injected into the eye, it was taken up in all layers of the retina but was cleared within 1–3 hours of delivery. This study indicates that a method to sustain the delivery of VCP to the retina is necessary to further investigate the effect of VCP as a complement inhibitor for retinal degenerations.

Effect of Temperature on Electrical Conductivity of Guaiacol-Guanidine Hydrochloride-Formaldehyde Copolymer Resin

The purpose of the present paper is to report temperature dependence of electrical conductivity on Guaiacol-guanidine hydrochloride-formaldehyde copolymer resin. By using a microwave irradiation technique, various ratios of copolymer resin were synthesized from the reacting monomers, i.e., guaiacol, guanidine hydrochloride and formaldehyde. The characterization of the copolymer resins has been fulfilled by spectral methods viz. ultraviolet visible (UV visible), infrared and proton nuclear magnetic spectroscopy (1H-NMR). The solid state direct current electrical conductivity of synthesized copolymer resins has been measured as a function of temperature. The electrical conductivity values of all the copolymers have been found in the range of a semiconductor.

Investigation of secondary phase separation and mechanical properties of epoxy SBS-modified asphalts

Styrene-butadiene-styrene triblock copolymer (SBS) and epoxy resin have been widely applied in asphalt modification. In the present work, industrial SBS-modified asphalt (SBA) was used to prepare epoxy SBS-modified asphalt (ESBA). The morphology, rheological, thermal and mechanical properties of ESBAs were characterized. LSCM observations revealed that the formation of phase-separated microstructures between epoxy and SBA in ESBAs. Secondary phase separation occurred in epoxy asphalts (EAs) with 50 and 60 wt% asphalts. The phase inversion occurred in epoxy asphalt with 60 wt% asphalt. In addition, the morphology of ESBAs also exhibited secondary phase separation. Two interlocked continuous phases appeared in SBA domains of ESBA with 40 wt% SBA. No phase inversion was observed in ESBA with 60 wt% SBA. The presence of SBS decreased the average size of dispersed domains in EA. The existence of SBS increased the initial viscosity of the epoxy asphalt during cure reaction. The viscosity of ESBA was low enough to satisfy the requirement for the pavement of steel bridge decks. The thermal stability of EA was enhanced with the existence of SBS. Furthermore, the presence of SBS significantly improved mechanical properties of the epoxy asphalt. Especially, the tensile strength, elongation at break and toughness of ESBA containing 60 wt% SBA were 125%, 55% and 113% higher than those of the epoxy asphalt with the same content of asphalt.

Syntheses of Diethylene Tricarbamide–Formaldehyde and Copolymer Resins and Their Low Formaldehyde-Emitting Binder Performance of Wood Composite Board

Abstract Diethylene tricarbamide–formaldehyde (DF) resins were investigated for syntheses at low mole ratios and at about 60 percent resin solids levels in water as low formaldehyde-emitting binders of wood composite boards. Tri-functional monomer D was shown to react readily with formaldehyde to form hydroxymethyl groups that then react to form methylene bonds between molecules to form DF resins of water-soluble oligomeric condensation products, similar to urea-formaldehyde (UF) resins. DF resins showed a better storage life and longer pot life than, and similar cure times as, UF resins. DF resins also bonded laboratory particleboard as effectively as UF resins in terms of hot-pressing parameters and resultant boards' physical properties, while the formaldehyde content (FC) values of boards were lower by about 75 percent than UF resins, at about 2.3 to 4.4 mg/100 g wood by the Perforator method, significantly below the current regulation levels. Copolymer resins made with up to 15 percent urea substitutions performed equally well as particleboard binders with only slightly increased FC values, indicating some cost savings possible for industry. Copolymer resins made with up to 25 percent melamine also performed well with similarly low FC values and improved the physical properties of boards, indicating some lowering of loading levels of resin solids possible for industry, especially in the formulating of face layer resins. DF and copolymer resins are considered to be adaptable in current resin and board manufacturing plants to produce wood composite boards with a low formaldehyde emission potentials and without loss of productivity and board quality, a problem present in the current wood composites manufacturing industries.

Synthesis and Characterization of polymer resins from renewable resource

As a alternate to the use of conventional reinforcing synthetic resins, biobased resins were synthesized from renewable resources such as cardanol and furfural. Cardanol is the meta- substituted phenolic compound isolated from cashew nut shell liquid, a byproduct of cashew industry. P-chloroaniline has been diazotised and coupled with cardanol to prepare diazotised p-chloroaniline cardanol dye (bio monomer). The obtained dye has been condensed with furfural in presence of 3 N H2SO4 to give diazotized p-chloroaniline cardanol furfural (homo polymer) resin. The condensed resin has been allowed to react with urea, ethylene glycol, resorcinol and o-hydroxy benzoic acid to form various copolymer resins. These resins have been characterized by Fourier transform-infrared spectroscopy, 1H-nuclear magnetic resonance spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis and differential thermal analysis studies. XRD techniques are used to distinguish the state of polymer, i.e. crystalline or amorphous etc., to calculate percentage crystallinity. The energy of activation for different stages of polyurethane degradation is determined by Coats–Redfern integration method which involves different kinetic models.

A Two-Step Bioconversion Process for Canolol Production from Rapeseed Meal Combining an Aspergillus niger Feruloyl Esterase and the Fungus Neolentinus lepideus.

Rapeseed meal is a cheap and abundant raw material, particularly rich in phenolic compounds of biotechnological interest. In this study, we developed a two-step bioconversion process of naturally occurring sinapic acid (4-hydroxy-3,5-dimethoxycinnamic acid) from rapeseed meal into canolol by combining the complementary potentialities of two filamentous fungi, the micromycete Aspergillus niger and the basidiomycete Neolentinus lepideus. Canolol could display numerous industrial applications because of its high antioxidant, antimutagenic and anticarcinogenic properties. In the first step of the process, the use of the enzyme feruloyl esterase type-A (named AnFaeA) produced with the recombinant strain A. niger BRFM451 made it possible to release free sinapic acid from the raw meal by hydrolysing the conjugated forms of sinapic acid in the meal (mainly sinapine and glucopyranosyl sinapate). An amount of 39 nkat AnFaeA per gram of raw meal, at 55 °C and pH 5, led to the recovery of 6.6 to 7.4 mg of free sinapic acid per gram raw meal, which corresponded to a global hydrolysis yield of 68 to 76% and a 100% hydrolysis of sinapine. Then, the XAD2 adsorbent (a styrene and divinylbenzene copolymer resin), used at pH 4, enabled the efficient recovery of the released sinapic acid, and its concentration after elution with ethanol. In the second step, 3-day-old submerged cultures of the strain N. lepideus BRFM15 were supplied with the recovered sinapic acid as the substrate of bioconversion into canolol by a non-oxidative decarboxylation pathway. Canolol production reached 1.3 g/L with a molar yield of bioconversion of 80% and a productivity of 100 mg/L day. The same XAD2 resin, when used at pH 7, allowed the recovery and purification of canolol from the culture broth of N. lepideus. The two-step process used mild conditions compatible with green chemistry.

Preparation and properties of copolymer resin based on polybenzimidazole and bisoxazoline

Reaction between the NH groups in polybenzimidazole (PBI) and bisoxazoline compounds (1,3‐phenylene bisoxazoline, 1,3‐PBO) resulted in the successful preparation of novel network polymers. Adjusting the amount of the bisoxazoline compound, which is a cross‐linking agent for the preparation of network polymers, and obtaining dynamic mechanical measurements, electrical resistivity measurements, thermomechanical measurements, and tensile tests allowed the determination of the heat resistance and mechanical strength of these novel network polymers. Examination of the elementary reaction of PBI and the1,3‐PBO curing reaction by using model compounds revealed that the NH group in the PBI structure reacted with the oxazoline group of 1,3‐PBO. Comparison of noncross‐linked PBI with the PBI network polymers obtained through cross‐linking reaction with bisoxazoline compounds demonstrated improvements in heat resistance and mechanical strength of the PBI‐bisoxazoline network polymers.