New terpolymers from n-butyl acrylate,glycidyl methacrylate and tetrahydrofurfuryl acrylate: Synthesis,characterisation and estimation of reactivity ratios

Development and practical application of multicomponent copolymerisation systems, such as terpolymerisation, is an on-going process because even a small addition of a particular comonomer may have a significant impact on the desired property. Commonly, three separate pairs of binary polymerisation experiments are carried out to obtain monomer reactivity ratios (MRR) values that relates to the ternary polymerisation reactions. However, the reaction conditions in each binary system may not be representative of the whole ternary system. The error-in-variables model (EVM) method is a relatively recent statistical approach to solving multi-response parameter estimation problems, with the advantage that all MRR parameters can be directly estimated from terpolymerisation data. New ternary copolymers derived from n-butyl acrylate (nBA), glycidyl methacrylate (GMA) and tetrahydrofurfuryl acrylate (THFA) were synthesised in solution at 70±1 °C in the presence of benzoyl peroxide (BPO) as a free radical initiator. The terpolymers were characterised by ¹H NMR, ¹³C NMR and FTIR spectroscopic techniques. The terpolymer compositions were determined using ¹H NMR analysis. The polydispersities of the terpolymers with values between 1.66 and 1.85 suggest a strong tendency for chain termination by disproportionation. The glass transition temperatures of the terpolymers are found to be between those of the corresponding homopolymers and relative to their content. Increase in the nBA or THFA contents and decrease in the GMA content in terpolymers results in a decrease in the glass transition temperatures. The determination of MRR for the ternary system was obtained by employing the EVM model. Experimental terpolymerisation data agree well with calculations based on the Alfrey-Goldfinger equation and the unitary and binary azeotropes were calculated.     

Copolymerization of benzyl methacrylate and a methacrylate bearing benzophenoxy and hydroxyl side groups: Monomer reactivity ratios,thermal studies and dielectric measurements

Statistical copolymers of 2-hydroxy-3-benzophenoxy propyl methacrylate (HBPPMA) and benzyl methacrylate (BzMA) in different feed ratios were synthesized by free radical copolymerization method at 60 °C in presence of AIBN initiator. The compositions of copolymer were estimated from ¹H-NMR technique. The monomer reactivity ratios of HBPPMA and BzMA were calculated as r₁ (r_HBPPMA)=0.51±0.076 and r₂ (r_BzMA)=1.07±0.140 for Kelen-Tüdos method, and was estimated as r₁=0.37±0.0006 and r₂=0.64±0.0485 according to Fineman Ross equation. The average values estimated from the two methods showed that monomer reactivity ratio of benzyl methacrylate was a slightly high in comparison to HBPPMA. The copolymer system showed an azeotropic point, which is equal to M _BzMA =m _BzMA =0.43. DSC measurements showed that the T_g’s of poly(HBPPMA) and poly(BzMA) were 84 °C and 73 °C, respectively. The T_g in the copolymer system decreased with increase in benzyl methacrylate content. The decomposition temperature of poly(BzMA) and poly(HBPPMA) occurs in a single stage at about 207 °C and 260 °C, respectively. Those of HBPPMA-BzMA copolymer systems are between decomposition temperatures of two homopolymers. The dielectric constant, dielectric loss factor and electrical conductivity were investigated depend on the frequency of the copolymers. The highest dielectric constants depending on all the studied frequencies were recorded for the poly(HBPPMA) and the copolymer containing the highest HBPPMA unit. The dielectric constant for P(HBPPMA) and P(BzMA) at 1 kHz are 6.56 and 3.22, respectively. Also, those of copolymer systems were estimated between these two values. Similarly, poly(HBPPMA) and copolymers, which are prepared under the same conditions show the dissipation factor and conductivity as well.     

Synthesis and characterization of novel biocompatible four-arm star-shaped copolymers by using a new tetramethacrylate core

The objective of this study was to synthesize and characterize two novel four-arm star-shaped copolymers of N-isopropylacrylamide (NIPAAm), methacrylic acid (MAA), N,N-(dimethylamino) ethyl methacrylate (DMAEMA) and 1-vinyl-2-pyrrolidone (VP) that was initiated from a new tetramethacrylate monomer (TMAM) as the core by the free radical polymerization approach. Novel multiacrylic monomer was synthesized via three key consecutive reactions. All the intermediates and the final product have been fully characterized. The polymerization reaction was conducted by the core first method and the star-shaped copolymers were analyzed by FT-IR, ¹H NMR and Thermo-Gravimetric Analysis (TGA). MTT assay was used to evaluate in vitro cytotoxicity of the star copolymers on lung cancer cell lines. These star copolymers showed no in vitro cytotoxicity to A549 cells. The results showed that these copolymers can be promising drug carriers because they showed no in vitro cytotoxicity and they have various functional groups for association and interaction with drugs.     

Synthesis of core-shell fluorinated acrylate copolymers and its application as finishing agent for textile

Core-shell fluorinated acrylate copolymers emulsion was thus synthesized via the core-shell emulsion polymerization with the fluorinated monomers and acrylic monomers as the main raw materials and its properties were studied. PFMA, the fluorinated acrylate monomers, was synthesized by the esterification of perfluorooctanoyl chloride (PFOC) and hydroxypropyl methacrylate (HPMA). Then the core-shell fluorinated acrylate copolymers emulsion with a poly(MMA/BA/St) core and a poly(PFMA/MMA/BA) shell was synthesized via a starved semi-continuous core-shell emulsion polymerization method by using KPS and sodium bicarbonate as the initiator/buffer system and SDS/Twain 80 as the commixture emulsifier. Lastly, the synthesized copolymers was applied as textile finishing agent for cotton textile. The results of FT-IR and NMR indicated that PFMA had been synthesized as expected and effectively combined in the emulsion copolymerization. The GPC, zeta potential, TEM and DSC showed that the particles had uniform spherical core-shell structure with a diameter of 65-150 nm, and the distribution and emulsion stability was satisfactory. As XPS, FESEM and AFM shown, a hydrophobic structure which was similar to the structure of the lotus leaf were formed and the surface hydrophobicity of the films can be improved. Based on the analysis of DSC, thermal stabilities of the films were enhanced with the increase of fluorine content. Besides, FESEM of textiles showed that the surface of treated textiles were smooth and the edges were clear and visible, indicating significant improvement of the performance on water and oil repellent.     

Synthesis and characterization of hybrid latexes from soybean oil-based polyurethane and poly(2,2,2-trifluoroethyl methacrylate)

A class of novel fluorine containing core-shell hybrid latexes were obtained from soybean oil-based polyurethanes and poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) by two-step synthesis under mild reaction conditions. Structural and morphology properties of the resulting hybrid latexs have been characterized by FT-IR and TEM. In addition, thermal properties (DSC, TGA) and coating performance (contact angle, stress-strain curve, and surface free energy) were investigated and discussed. The hybrid latexes exhibit outstanding thermal stability and coating performance. More importantly, through this method, low-valued foods are successfully transformed into high-valued functional materials which bring new solutions for preparing materials from renewable sources.     

Synthesis and characterization of sodium acrylate and 2-acrylamido-2-methylpropane sulphonate (AMPS) copolymer gels

A series of superabsorbents based on acrylic acid (AA), sodium acrylate, 2-acrylamido-2-methylpropane sulphonic acid, N,N′-methylene bis-acrylamide (MBA) were prepared by inverse suspension polymerization. These hydrogels were further crosslinked on the surface with polyethylene glycol-600 (PEG-600). The water absorbency or swelling behaviors for these xerogels in water and 0.9% saline solutions, both under free condition and under load were investigated. Absorption characteristics of these hydrogels were found to depend on nature and concentration of crosslinker in the system. It was also found that the saline absorption was significantly improved as the incorporation of AMPS in the polymer was increased. The surface crosslinking introduced in the polymers was found to improve the absorption under load characteristics without lowering the free water absorption capacities of the polymer to a considerable extent.     

Synthesis and characterization of new polyamides containing symmetrical and unsymmetrical thiadiazole rings

Diamino derivatives of thiadiazole namely, 2,5-diamino-1,3,4-thiadiazole and 3,5-diamino-1,2,4-thiadiazole were synthesized and characterized. Polyamides were synthesized by condensation of the two diamino derivatives with diacide chlorides. The structures of polyamides were verified by elemental analysis, FTIR, ¹H-NMR, ¹³C-NMR and mass spectroscopy. The polyamides possess good solubility in aprotic organic solvents such as DMF, DMAC, DMSO and NMP at room temperature. Intrinsic viscosity measurements indicate that the polyamides synthesized have moderate molecular weights. The thermal stability of these polyamides in nitrogen atmosphere is relatively good, especially for those polyamides containing phenylene ring in the backbone. Compared to the structurally related Kevlar aramide, using 2,5-diamino-1,3,4-thiadiazole and 3,5-diamino-1,2,4-thiadiazole instead of p-phenylene diamine results in reducing the melting points of polyamides to below 350 °C.     

Synthesis and crystallization behaviors of modified PET copolymers

A series of random copolyesters having various compositions were synthesized by bulk copolymerization of bishydroxyethyl terephthalate (BHET) with 1,4-cyclohexane dimethanol (CHDM) or dimethyl isophthalate (DMI). CHDM and DMI content was less than 10 wt%. For the synthesized copolyesters, isothermal crystallization rate, melting behavior, and equilibrium temperature were investigated by calorimetry and by Avrami and Hoffman-Weeks equation. Crystalline lattice and morphology were studied by WAXD and SEM. Regardless of the composition, the value of the Avrami exponent was about 3, which indicates that crystallization mechanism of the copolyester was similar to those of PET homopolymer. Incoporation of CHDM or DMI units in PET backbone decreased the crystallization rate of the copolyesters. Surface free energy of copolyesters was evaluated using the newly proposed equation. The value of surface free energy was about 189×10⁻⁶ J²/m⁴ regardless of comonomer contents. This result is in good agreement with that of PET homopolymer.     

Acrylamide/potassium 3-sulfopropyl methacrylate/sodium alginate/bentonite hybrid hydrogels: Synthesis,characterization and its application in lauths violet removal from aqueous solutions

In this report, it was to investigate that the swelling and dye sorption properties of a series of novel hybrid composite hydrogel sorbent systems containing polysaccharide/clay polyelectrolyte based on acrylamide/potassium 3-sulfopropyl methacrylate and sodium alginate, and clay such as bentonite were synthesized with free radical solution polymerization by using ammonium persulfate/N,N,N’,N’-tetramethylethylenediamine as redox initiating pair in presence of poly(ethylene glycol) diacrylate as a crosslinker. Swelling experiments were performed in water at 25 °C, gravimetrically. The hydrogels, the semi-interpenetrating polymer networks, and the hybrid composite hydrogel systems that synthesized in this study have showed high water absorbency. Some swelling and diffusion properties were calculated, and they were discussed for the hybrid hydrogel systems prepared under various formulations. The equilibrium percentage swelling degree of highly swollen hybrid composite hydrogel systems ranges are 718-2055 %. FT-IR analysis and SEM technique were applied for characterization. For sorption of water-soluble cationic dye such as lauths violet into the hydrogel systems was studied by batch sorption technique at 25 °C. For equilibrium sorption studies, dye sorption percentage, dye uptake performance, and partition coefficient of the hydrogel systems have been investigated. The values of dye sorption percentage of the hydrogels were changed among 87.11-96.39 %. Consequently, the hydrogel systems developed in this study could serve as a potential device for water and dye sorbent.     

Synthesis and properties of acrylonitrile-methyl itaconate copolymers as spun carbon fiber precursors

Acrylonitrile-methyl itaconate (AN-MIA) copolymers were successfully prepared by free-radical solution copolymerization, and then were spun into precursors of carbon fibers by one-step wet-spun method in this study. Effect of methyl itaconate(MIA), itaconic acid (IA) and methyl acrylate (MA) on the characteristics of the copolymers and precursors were studied in contrast. The monomer reactivity ratios for AN/MIA system were determined by Kelen-Tudos (K-T) method with r ₁=0.65, r ₂=1.80. The viscosity test shows that using MIA as a co-monomer is an effective way to decrease the viscosity of PAN solution. During the spinning and stretching processes, polyacrylonitrile (PAN) copolymer with MIA as co-monomer can reach the higher total draw-ratio of 12.0 folds, while PAN copolymer with IA as co-monomer can reach only 8.5 folds. The fineness and elongation at-break of the PAN precursors with MIA as co-monomer improve, but the tenacity decreases. DSC test shows MIA is less effective in improving the thermal property than IA.     

Synthesis and properties of Nylon 4/5 copolymers for hydrophilic fibers

Nylon 4, which can be synthesized by anionic ring-opening polymerization, has good mechanical properties and a very high affinity for water owing to its high polarity. On the other hand, despite its high melting temperature, the polymer has not been commercialized because of its low thermal stability. In this study, copolymerization of 2-pyrrolidone (C4) with 2-piperidone (C5) was performed to reduce the melting temperature of Nylon 4 homopolymer. The copolymerization reaction was controlled by changing the comonomer content, catalyst content, temperature, initiator content, and reaction time. The Nylon copolymers were characterized by ¹H-nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The hydrophilic properties of Nylon 4 and its copolymers were evaluated by surface free energy analysis and moisture regain measurement. The intrinsic viscosity and polymerization yield of Nylon 4 increased with increasing catalyst concentration until 5 mole% and decreased with further increases in catalyst loading. The proton NMR spectrum revealed the composition of the Nylon 4/5 copolymer to be 62.5 % C4 moiety at a 5:5 comonomer feed ratio. The melting temperature of the Nylon 4/5 copolymers decreased considerably according to the composition. The moisture regain of the Nylon 4/5 copolymer was higher than 6.4 % even at 77.3 % C4 in composition.     

Spinning of polyacrylamidoximes by solution blowing technique: Synthesis and characterization

A novel route for the production of polyacryloamidoxime nano-fibers is described. The innovative solution blowing spinning technique is used for the production of polyacryloamidoxime nano-fibers. The polyacryloamidoxime was prepared by the amidoximation of the acrylonitrile groups in a non-aqueous medium (DMF) using the least possible amount of hydroxylamine. A comparison study was performed to evaluate the effectiveness of the amidoximation reaction in aqueous or non-aqueous media. As the presented method is acquiring only 0.5 g/g hydroxylamine, at 50 °C for 7 h to achieve 63.1 % conversions, also solution blowing is an alternative technique for manufacturing of micro- and nano-fibers. The morphological structure, the chemical nature as well as the dyeability of the obtained fibers are illustrated. The obtained nano polyacryloamidoxime fibers show superior adsorption ability toward copper ions. Results showed that the present work presents a promising synthesis root for spinnable polyacryloamidoxime.     

Synthesis and characterization of hazelnut oil-based biodiesel

The demand for diesel fuel far exceeds the current and future biodiesel production capabilities of the vegetable oil and animal fat industries. New oilseed crops that do not compete with traditional food crop are needed to meet existing energy demands. Hybrid hazelnut oil is just such an attractive raw material for production of biodiesel. Hazelnut oil was extracted from hybrid hazelnuts and the crude oil was refined. Hazelnut oil-based biodiesel was prepared via the transesterification of the refined hazelnut oil with excess methanol using an alkaline catalyst. The effects of reaction temperature, time and catalyst concentration on the yield of diesel were examined, and selected physical and chemical properties of the biodiesel were evaluated. The biodiesel yield increased with increasing temperature from 25 to 65 °C and with increasing catalyst concentration from 0.1 to 0.7 wt%. The increase in yield with reaction time was nonlinear and characterized by an initial faster rate, followed by a slow rate. Hazelnut oil-based biodiesel had an average viscosity of 8.82 cP at 25 °C, which was slightly higher than that of the commercial soy-based diesel (7.92 cP at 25 °C). An approximate 12 °C higher onset oxidative temperature and a 10 °C lower cloud point of hazelnut oil biodiesel than those of its commercial soy counterpart indicated a better oxidative stability and flowability at low temperature. The average heat of combustion of hazelnut oil biodiesel was 40.23 kJ/g, and accounted for approximately 88% of energy content of diesel fuel. The fatty acid composition of hazelnut oil-based biodiesel was the same as the nature oil.     

Synthesis and characterization of copolyester sizing agents

The effect of main chain structure of anion-containing copolyesters on the properties of copolyester sizing agents was investigated. The copolyesters were prepared by conventional two step polymerization technique from DMT, DMI, DMS, EG, and DEG. The copolyesters synthesized were characterized by atomic absorption spectroscopy,¹H-NMR Spectroscopy, GC, FTIR Spectroscopy, and DSC. The solubility decreased as the DMT content increased. The copolyesters having DMT:DMI=1:1 showed the minimum viscosity. The effect of EG content on the solution stability was not clear and the samples having high DMI content showed better solution stability. The water resistance was best when only DMI and EG were used, while it was worst when DMT:DMI was 1:0.     

TEMPO-mediated oxidation of MCC at high temperature: Synthesis and characterization of high-hydrophilic polymer

Microcrystalline cellulose was reacted with catalytic amounts of 2, 2, 6, 6-tetramethyl-1-piperidine oxoammonium salt (TEMPO), sodium hypochlorite and sodium bromide in Na₂CO₃/NaHCO₃ buffer solution at different temperatures (30 °C, 40 °C, 50 °C). The oxidation procedures included first oxidation and second oxidation. The yield of cellouronic acid produced in the second oxidation was higher than the yield of cellouronic acid produced in the first oxidation at the same oxidation temperature. Moreover, an interesting “high-hydrophilic” phenomenon appeared at higher temperature during microcrystalline cellulose second oxidation (30 °C, 40 °C, 50 °C). Properties associated with the chemical characteristics are discussed by XRD, FTIR, ¹³C-NMR and Laser Particle Analyzer in view of its interesting high-hydrophilic effects.     

Synthesis and characterization of Polyaniline composite with Shell membrane

Polyaniline (PANI) and shell membrane composites have been synthesized via chemical oxidative polymerization of aniline in the presence of shell membrane. Combination of surfactant, PANI, and shell membrane allows production of conductive textile with smooth surface. Fourier transform infrared spectroscopy (FTIR) measurements suggest that the oxidation degree of PANI was affected by the initial ratio of shell membrane vs. monomer amount. The PANI/shell membrane composites were characterized with UV-vis absorption spectroscopy, electron spin resonance (ESR) spectroscopy. Electrical conductivity of the composites was measured with four-probe method. The surface of the composites was observed with scanning electron microscopy (SEM). Thermal stability of the composites was discussed with the result of thermogravimetric analysis.     

Novel cationic softener containing MCT reactive dyes for cotton: Synthesis and characterization

Two novel cationic softener containing mono-s-chloro triazinyl reactive dyes together with their analogues were designed. The dyes were synthesized via reacting an N,N-dimethyldodecylamine with p-nitrobenzyl bromide. The resultant was reduced using stannous chloride and hydrochloric acid to produce the primary amine. The quaternary ammonium salt containing primary amine was then diazotized to produce diazonium salt part of azo dye. The diazonium salt was then coupled to H-acid/J-acid reacted with cyanuric chloride and sulfanilic acid. The analogue dyes were prepared via the same route without quaternary ammonium salt making stage. The chemical structures of the novel dyes were characterized by FTIR, ¹H-NMR, and elemental analysis. The spectroscopic properties of the dyes were determined in terms of λ _max and ? _max in aqueous solution.     

Crystallization behavior,rheology, mechanical properties,and enzymatic degradation of poly(L-lactide)/poly(D-lactide)/glycidyl methacrylate grafted poly(ethylene octane) blends

Poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA)/poly(ethylene octene) grafted with glycidyl methacrylate (GPOE) were prepared by simple melt blending method at PDLA loadings from 1 to 5 wt%. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) demonstrated the formation of the stereocomplex in the blends. The addition of PDLA led to the increase of nucleation density from polarized microscope (POM) observations. Rheological measurements indicated that the blends exhibited a rheological fluid-solid transition and an enhanced elastic behavior in that ternary system as the PDLA loadings reached up to 5 wt%. By adding 1-2 wt% PDLA, the ternary system has better tensile and impact properties. Dynamic Mechanical Analysis (DMA) results showed that SC crystal formation and its effect on the enhancement of thermal stability at higher temperature. It is interesting that the enzymatic degradation rates have been enhanced clearly in the PLLA/PDLA/GPOE blends than in the PLLA/GPOE blend, which may be of great use and significance for the wider practical application of PLLA/GPOE blends.     

Synthesis and hydrophilicities of Poly(ethylene 2,6-naphthalate)/Poly(ethylene glycol) copolymers

Poly(ethylene 2,6-naphthalate) (PEN)/Poly(ethylene glycol) (PEG) copolymers were synthesized by two step reaction during the melt copolymerization process. The first step was the esterification reaction of dimethyl-2,6-naphthalenedicarboxylate (2,6-NDC) and ethylene glycol (EG). The second step was the condensation polymerization of bishydroxyethylnaphthalate (BHEN) and PEG. The copolymers contained 10 mol% of PEG units with different molecular weights. Structures and thermal properties of the copolymers were studied by using¹H-NMR, DSC, TGA, etc. Especially, while the intrinsic viscosities of PEN/PEG copolymers increased with increasing molecular weights of PEG, but the glass transition temperature, the cold crystallization temperature, and the weight loss temperature of the copolymers decreased with increasing molecular weights of PEG. Consequently, the hydrophilicities by means of contact angle measurement and moisture content of the copolymer films were found to be significantly improved with increasing molecular weights of PEG.     

Synthesis and hydrophilicity of poly(trimethylene 2,6-naphthalate)/poly(ethylene glycol) copolymers

Poly(trimethylene 2,6-naphthalate) (PTN)/poly(ethylene glycol) (PEG) copolymers were synthesized by the two-step melt copolymerization process of dimethyl-2,6-naphthalenedicarboxylate (2,6-NDC) with 1,3-propanediol (PD) and PEG. The copolymers produced had different PEG molecular weights and contents. The structure, thermal property, and hydrophilicity of these copolymers were studied by proton nuclear magnetic resonance (¹H-NMR) analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and by contact angle, moisture content, and instantaneous elastic recovery measurements. The intrinsic viscosity and the instantaneous elastic recovery of the PTN/PEG copolymers increased with increasing PEG molecular weight and content, whereas the glass transition, melting, and cold crystallization temperatures, and the heat of fusion of the PTN/PEG copolymers all decreased with increasing PEG molecular weight or content. The thermal stability of the copolymers was not affected by PEG molecular weight or content. The hydrophilicity, as determined by contact angle and moisture content measurements of the copolymer films, was significantly improved with increasing PEG molecular weight and content.