Synthesis and characterization of functional copolymers of citronellol with butylmethacrylate initiated by benzoyl peroxide

Benzoyl peroxide (BPO)‐initiated free radical copolymerization of citronellol with butylmethacrylate (BMA) in xylene at 80°C ± 0.1°C under the inert atmosphere of nitrogen has been studied. The kinetics expression is R_p α [I]^0.5±0.27 [citronellol]^1.0±0.13 [BMA]^1.0±0.18. The overall activation energy has been calculated as 65 kJ/mol. Bands at 3436 and 1732 cm^?1 in the FTIR spectrum of the copolymer(s) have indicated the presence of hydroxy, ester group of citronellol and butylmethacrylate, respectively. The ¹H‐NMR spectrum shows peaks at 7.0–7.7 δ due to ? OH proton of citronellol and at 3.2–4.0 δ due to ? OCH₂ proton of butylmethacrylate. The molecular weight M_v and η_int of the copolymers have been measured with the help of gel permeation chromatography in tetrahydrofuran at 25°C to calculate Mark‐Houwink constants as K = 2.68 × 10^?4 and α = 0.34 ± 0.40. The alternating nature of the copolymer is confirmed by reactivity ratios r₁ (BMA) = 0.023 ± 0.004 and r₂ (Citronellol) = 0.0025 ± 0.22. The Alfrey‐Price Q‐e parameters for citronellol have been calculated as Q₂ = 0.13 and e₂ = –1.28. Thermal decompositions of copolymer are evaluated with the help of thermal gravimetric analysis technique. The mechanism of copolymerization has been elucidated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of functional copolymer of Linalool and vinyl acetate: A kinetic study

Linalool (LIN) and vinyl acetate (VA) were copolymerized by benzoyl peroxide (BPO) in p‐xylene at 60°C for 90 min. The system follows nonideal kinetics: R_pα[I]^0.6[LIN]^1.2[VA]^1.1. It results in the formation of alternating copolymer as evidenced from reactivity ratios as r₁ (VA) = 0.01, r₂ (LIN) = 0.0015, which have been calculated by Kelen–Tudos method. The overall activation energy is 82 kJ/mol. The FTIR spectrum of the copolymer shows the presence of the band at 3425 cm^?1 due to alcoholic group of LIN and at 1641 cm^?1 due to >C?O group of VA. The ¹H‐NMR spectrum shows peaks at 7.0–7.7 δ due to hydroxy proton of LIN and at 1.0–1.4 δ due to acetoxy protons of VA. ¹³C‐NMR spectrum of copolymer shows peaks at 167 ppm due to acetoxy group and at 75–77 ppm due to C? OH group. The Alfrey–Price Q–e parameters for LIN has been calculated as Q₂ = 1.24 and e₂ = 3.11. The copolymer is highly thermally stable and has a glass transition temperature (T_g) of 85°C, evaluated from DSC studies. The mechanism of copolymerization has been elucidated. This article also reports measurement of Mark–Houwink constants in THF at 25°C by means of GPC as α = 0.8 and K = 3.0 × 10^?4 dl/g. The thermal decompositions of copolymer are established with the help of TGA technique. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1134–1143, 2004     

Synthesis and characterization of copolymer of styrene with methacrylic acid initiated by triphenylbismuthonium 1,2,3,4‐ tetraphenylcyclopentadienylide

The radical copolymerization of styrene with methacrylic acid (MAA) initiated by triphenylbismuthonium 1,2,3,4‐tetraphenylcyclopentadienylide in dioxan at 80 ± 0.1 °C for 3 h results in the formation of alternating copolymer as evidenced from the values of reactivity ratios as r₁ (styrene) = 0.03 and r₂ (MAA) = 0.025. The kinetic expression is R_p α [I]^0.5 [Sty] [MAA] and overall energy of activation is computed to be 23 kJ/mol. The FTIR spectrum of the copolymer shows the presence of bands at 3054 cm^?1 assigned to the phenyl group of styrene and at 1724 cm^?1 assigned to the ? COOH group of MAA. The ¹H‐NMR spectrum of the copolymer shows peaks between 7.20 and 7.27 δ assigned to the phenyl protons of styrene and at 12.5 δ assigned to the COOH proton of MAA. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1838–1843, 2005     

Disecondary amine synthesis and its reaction kinetics with epoxy prepolymers

3,3′‐Diaminodiphenyl sulfone (3,3′‐DDS) was reacted with acetaldehyde in the presence of sodium triacetoxy borohydride via reductive amination to yield a 3,3′‐DDS based secondary diamine, N,N′‐diethyl‐3,3′‐diaminodiphenyl sulfone. Near IR analysis indicated that the 5060 cm^?1 peak for primary amine (? NH₂) in 3,3′‐DDS was absent in the reaction product spectrum. The ? NH₂ proton peak at δ 5.66 ppm shifted to δ 6.16 ppm in the product. Methyl and methylene protons of CH₃? CH₂? NH? Ph? group were observed at δ 3.01 and 1.12 ppm, respectively, in the product. The carbon NMR spectrum of the reaction product showed new peaks at δ 37.46 and 14.47 ppm that further confirmed secondary amine formation. The liquid chromatography coupled mass spectra peaks at 248–250 for 3,3′‐DDS and 304 for the reaction product further supported the formation of N,N′‐diethyl‐3,3′‐diaminodiphenyl sulfone. A blend of N,N′‐diethyl‐3,3′‐diaminodiphenyl sulfone with diglycidyl ether of bisphenol‐A (DGEBA) epoxy prepolymer started reacting at about 110–125°C surpassing an energy barrier of ～ 66 kJ/mol as determined via differential scanning calorimetry analysis. Reaction kinetics were characterized via near IR spectroscopy specific to the reaction between secondary amine and DGEBA epoxy prepolymer. The results confirmed >97% conversion at a cure protocol of 5 h at 80°C, 5 h at 100°C, 11 h at 125°C, and 6 h at 185°C. N,N′‐diethyl‐3,3′‐diaminodiphenyl sulfone‐DGEBA thermoplastics displayed tensile and flexural modulii of 3.08 and 2.86 GPa, respectively, and glass transition temperature (T_g) of 120.77°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Benzoyl peroxide–p‐acetylbenzylidenetriphenyl arsoniumylide initiated copolymerization of citronellol and styrene

Alternating copolymers, containing styrene and citronellol sequences, have been synthesized by radical polymerization using benzoylperoxide (BPO)–p‐acetylbenzylidenetriphenyl arsoniumylide (pABTAY) as initiator, in xylene at 80 ± 1 °C for 3 h under inert atmosphere. The kinetic expression is R_p ∝ [BPO]^0.88 [citronellol]^0.68 [styrene]^0.56 with BPO and R_p ∝ [pABTAY]^0.27 [citronellol]^0.76 [styrene]^0.63 with pABTAY, ie the system follows non‐ideal kinetics in both cases, because of primary radical termination and degradative chain transfer reactions. The activation energy with BPO and pABTAY is 94 kJ mol^?1 and 134 kJ mol^?1, respectively. Different spectral techniques, such as IR, FTIR, ¹H NMR and ¹³C NMR, have been used to characterize the copolymer, demonstrating the presence of alcoholic and phenyl groups of citronellol and styrene. The alternating nature of the copolymer is shown by the product of reactivity ratios r₁ (Sty) = 0.81 and r₂ (Citro) = 0.015 using BPO and r₁ (Sty) = 0.37 and r₂ (Citro) = 0.01 using (pABTAY), which are calculated by the Finemann–Ross method. A mechanism of copolymerization is proposed. © 2001 Society of Chemical Industry     

Synthesis and characterization of a terpolymer of limonene,styrene, and methyl methacrylate via a free‐radical route

The free‐radical terpolymerization of a monocyclic terpene, namely, limonene (Lim), with styrene (Sty) and methyl methacrylate (MMA) in xylene at 80 ± 0.1°C for 2 h, with benzoyl peroxide (BPO) as an initiator under an inert atmosphere of nitrogen was extensively studied. The kinetic expression was R_pα[BPO]^0.5[Sty]^1.0[MMA]^1.0[Lim]^?1.0, where R_p is the rate of polymerization. The overall energy of activation was calculated as 26 kJ/mol. R_p decreased as [Lim] increased. This was due to a penultimate unit effect. The Fourier transform infrared spectra of the terpolymer showed bands at 3025–3082, 1728, and 2851–2984 cm^?1 due to C? H stretching of phenyl (? C₆H₅) protons of Sty, ? OCH₃ of MMA, and trisubstituted olefinic protons of Lim, respectively. The ¹H‐NMR spectra showed peaks at 7.3–8.1, 3.9–4.4, and 5.0–5.5 δ due to the phenyl, methoxy, and trisubstituted olefinic protons of Sty, MMA and Lim, respectively. The values of the reactivity ratios r₁ (MMA; 0.33) and r₂ (Sty + Lim; 0.06) were calculated with the Kelen–T?udos method. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2343–2347, 2004     

Chitosan functionalization with a series of sulfur‐containing α‐amino acids for the development of drug‐binding abilities

Chitosan (Chi; 0.5 g) in 69.66 mM aqueous acetic acid was mixed with 312.4 mM methionine (methi) at 0.01 mL/s to disperse and cause optimum collisions for supporting condensation reactions through ? NH₂ of Chi and ? COOH groups of methi. The functionalized chitosan (f‐Chi) product with methi developed an amide bond, which was represented as methi‐functionalized chitosan [Chi–NH? C(?O)–methi]. Both the 1‐Ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC) and Dean–Stark methods were followed for Chi functionalization. Sulfonation with chlorosulfonic acid in a dimethylformamide medium was conducted at 90 °C and 750 rpm with an approximately 72% yield. The Chi–NH? C(?O)–methi was characterized by ¹H‐NMR spectroscopy and Fourier transform infrared stretching frequencies. The onset temperature of 280 °C recorded by thermogravimetric analysis/differential scanning calorimetry analysis, confirmed the high stability of the covalent bonds in Chi–NH? C(?O)–methi. The synthesis was repeated with other series members of sulfur (S) atoms containing α‐amino acids: homocysteine, ethionine, and propionine. The shielding of terminal ? CH₃ was enhanced on elongation of the terminal alkyl chain in the case of propionine. The peak for the ? NH₂ of Chi at a δ value of 4.73 ppm shifted to 5.36 ppm in Chi–NH? C(?O)–methi because of the involvement of ? NH₂ in ? NH? C(?O)? . Theoretically, the value of ? NH₂ of Chi was 5.11 ppm, with a difference of 0.38 ppm as compared to the experimentally determined value of 4.73 ppm. Additionally, a new peak at a δ value of 3.26 ppm also confirmed Chi functionalization. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46000.     

Copolymerization of N‐substituted maleimide with alkyl acrylate and its industrial applications

A series of new copolymers with desired thermal stability and mechanical properties for applications in leather industry were synthesized from various substituted maleimides and alkyl acrylates. Polymerization was carried out by a free‐radical polymerization using benzoyl peroxide (BPO) as initiator. The monomers and polymers synthesized were characterized by elemental analysis, IR, and nuclear magnetic resonance (NMR). Interestingly, these polymers were soluble in common organic solvents. Copolymer composition and reactivity ratios were determined by ¹H‐NMR spectra. The molecular weights of the polymers were determined by gel permeation chromatography. The homo‐ and copolymer of maleimide showed single‐stage decomposition (ranging from 300–580°C). The initial decomposition temperatures of poly[N‐(phenyl)maleimide] [poly(PM)], poly[N‐4‐(methylphenyl)maleimide] [poly(MPM)] and poly[N‐3‐(chlorophenyl)maleimide] [poly(CPM)] were higher compared to those of the copolymers. Heat‐resistant adhesives such as blends of epoxy resin with phenyl‐substituted maleimide‐co‐glycidyl methacrylate copolymers with improved adhesion property were developed. Different adhesive formulations of these copolymaleimides were prepared by curing with diethanolamine at two different temperatures (30°C and 60°C). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1870–1879, 2001     

A copolymer of poly[2,2′‐(m‐phenylene)‐5,5′‐ bibenzimidazole] and poly(2,5‐benzimidazole) for high‐temperature proton‐conducting membranes

A novel copolymer of polybenzimidazoles was prepared by copolymerization of 3,3′‐diaminobenzidine tetrahydrochloride, 3,4‐diaminobenzoic acid and isophthalic acid in polyphosphoric acid at 200 °C. The polymerization could be performed within 90–110 min with the assistance of microwave irradiation. The solubility of the copolymer obtained in N,N‐dimethylacetamide (DMAc) was improved compared with those of poly[2,2′‐(m‐phenylene)‐5,5′‐bibenzimidazole] and poly(2,5‐benzimidazole). Thus copolymer membranes could be readily prepared by dissolving the copolymer powders in DMAc with refluxing under ambient pressure. The decomposition temperature of the copolymer was about 520 °C in air according to thermogravimetric analysis data. The proton conductivity and mechanical strength of the phosphoric acid‐doped copolymer membranes were investigated at elevated temperatures. A conductivity of 0.09 S cm^?1 at 180 °C and a tensile stress at break of 5.9 MPa at 120 °C were achieved for the acid‐doped copolymer membranes by doping acids in a 75 wt% H₃PO₄ solution. Copyright © 2010 Society of Chemical Industry     

Phase‐transfer catalysis: Free‐radical polymerization of acrylonitrile using potassium peroxomonosulphate– tetrabutyl phosphonium chloride catalyst system: A kinetic study

This article presents the systematic study of kinetics and mechanism of phase‐transfer‐catalyzed free‐radical polymerization of acrylonitrile (AN) and water‐soluble initiator potassium peroxomonosulphate (PMS) coupled with tetrabutyl phosphonium chloride (TBPC) in ethyl acetate/water biphase system in the temperature range 45–55°C at fixed pH and ionic strength. The rate of polymerization increases with an increase in concentrations of AN, PMS, and phase transfer catalyst, PTC. It was observed that R_p is proportional to [AN]^1.5, [KHSO5₅⁻]^0.5, and [TBPC]^0.5. A suitable kinetic scheme has been proposed to account for the experimental observations and its significance was discussed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1564–1571, 2000     

Studies on damping properties of P(MMA‐AN)/P(EA‐nBA) LIPNs

Using a two‐stage emulsion polymerization method, a series of poly(methyl methacrylate‐acrylonitrile)/poly(ethyl acrylate‐n‐butyl acrylate) [P(MMA‐AN)/P(EA‐nBA)] latex interpenetrating polymer networks (LIPNs) were synthesized by varying AN content, ratio of network I/network II, crosslinker content, and introducing chain transfer agent. The damping properties of the LIPNs were investigated using a Rheovibron Viscoelastometer. The results indicates that a suitable content of AN can improve the damping properties of the LIPNs. Three kinds of fillers were incorporated into the LPINs, respectively, to measure the change in the damping properties. Mica and TiO₂ both increased the damping properties of the LIPNs over the wide temperature range. For TiO₂‐filled LIPNs, it was observed that the tan δ values exceeded 0.4 over 112.6°C temperature range from −50 to 72.6°C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 722–727, 2000     

Synthesis and characterization of polyacrylonitrile pregelled starch graft copolymers using ferrous sulfate‐hydrogen peroxide redox initiation system as surface sizing agent

A graft copolymer was synthesized by graft copolymerization of starch with styrene (St) and butyl acrylate (BA), using ferrous sulfate‐hydrogen peroxide redox initiation system. The starch was pregelled in the presence of acrylonitrile (AN) in aqueous alkali at high temperature before graft polymerization. Major factors affecting the polymerization reaction were investigated. It was found that a graft copolymer with higher percentage conversion (PC), graft efficiency (GE) and graft percentage (GP) was obtained by controlling the initiator concentration, concentration, and ratio of monomers and polymerization temperature. The optimum conditions were as follows: H₂O₂ concentration, 12%; monomer concentration, 120%; St/BA ratio, 1 : 1; polymerization temperature, 65°C. Fourier transform infrared spectroscopy and NMR analyses were used to gain information on the structure of the products. It was demonstrated that St, BA, and AN had been successfully grafted onto starch and ? CN had been saponified into ? CONH₂ and ? COO^? to a certain degree when pregelling. Scanning electron microscope micrographs showed the coarse structure and broad network. The graft polymerization took place on the surface of starch granule and led to amorphization of the starch structure. Graft polymer had better thermal stability and was endowed with pseudo‐plasticity. It was observed that the starch graft copolymer offers good properties such as water resistance as surface‐sizing agent. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Characterization of block copolymers based on poly[3,3-bis(ethoxymethyl)oxetane] and other novel polyethers

Diblock, triblock, and alternating block copolymers based on poly[3,3-bis(ethoxymethyl) oxetane] [poly(BEMO)] and a random copolymer center block poly(BMMO-co-THF) composed of poly[3,3-bis(methoxymethyl)oxetane] [poly(BMMO)], and poly(tetrahydrofuran) [poly(THF)] were synthesized and characterized with respect to molecular weight. Glass transition temperatures T_g and melting temperatures T_m were characterized via DSC, modulus–temperature, and dynamic mechanical spectroscopy (DMS). These polyethers had T_m between 70°C and 90°C, and T_g between ?55°C and ?30°C. The degree of crystallinity of poly(BEMO) was found to be 65% by X-ray powder diffraction. Tensile properties of the triblock copolymer, poly(BEMO-block-BMMO-co-THF-block-BEMO) were also studied. A yield point was found at 4.1 × 10⁷ dyn/cm² and 10% elongation and failure at 3.8 × 10⁷ dyn/cm² and 760 % elongation. Morphological features were examined by reflected light microscopy and the kinetics of crystallization were studied. Poly(BEMO) and its block copolymers were found to form spherulites of 2–10 μm in diameter. Crystallization was complete after 2–5 min.     

Improvement in Low Temperature Izod Impact Strength of SAN/ASA/HNBR Ternary Blends Considering Competing Effects of Glass Transition Temperature and Compatibility

The competing effects of glass transition temperature (T_g) and compatibility on the low temperature Izod impact toughness of styrene–acrylonitrile copolymer/acrylonitrile–styrene‐acrylate terpolymer (SAN/ASA, 75/25, w/w) blends were investigated by using a series of hydrogenated nitrile butadiene rubbers (HNBRs) with different acrylonitrile (AN) contents. The results showed that the HNBR with AN mass content ranging from 21% to 43% had good compatibility with polymer matrix and exhibited dramatic toughening effect at 25°C. Owing to their low T_gs, only the HNBRs (AN = 21% and 25%) remained favorable toughening effect at 0 and ?30°C, respectively. Furthermore, the HNBR with 0% AN content was represented by butadiene rubber (BR). Although, BR has an extremely low T_g (?94.5°C), it is incompatible with polymer matrix, and then could not toughen the material at three temperatures (?30, 0, and 25°C, respectively). Various characterizations including solubility parameters, scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA), Fourier transform infrared (FTIR) spectroscopy, and so on were carried out to elucidate the toughening mechanism. J. VINYL ADDIT. TECHNOL., 25:225–235, 2019. © 2018 Society of Plastics Engineers     

Determination of oxygen nonstoichiometry in SrFeO3−δ by solid‐state Coulometric titration

The oxygen nonstoichiometry of SrFeO_3?δ was determined by solid‐state Coulometric titration at 750°C‐1040°C and 10^?18≤pO₂(atm)≤0.5. At T≤850°C, a hysteresis in the oxygen nonstoichiometry (δ) isotherms indicates the presence of a two‐phase region corresponding to a mixture of a perovskite and an oxygen vacancy ordered phase. The variation of δ with temperature at fixed pO₂ values and the variation of log(pO₂) with reciprocal temperature at fixed δ are reported. The pO₂ at the p‐n transition in the electrical conductivity increases as the temperature increases, and the transition in the conductivity isotherm occurs at a composition of SrFeO_2.505(1) at 950°C and SrFeO_2.508(1) at 900°C. Since strontium exclusively occupies the A‐site, a simple point defect model that assumes noninteracting defects can describe the isotherms but only at 1040°C; nonideal behavior is observed at lower temperatures. The partial molar thermodynamic quantities for oxygen in SrFeO_3?δ were determined.     

Synthesis and crosslinking behavior of a soluble,crosslinkable, and high young modulus poly(arylene ether nitriles) with pendant phthalonitriles

Poly(arylene ether nitriles) (PEN) with pendant phthalonitrile groups (PEN? CN) were obtained via the Yamazaki‐Higashi phosphorylation route of 4‐(4‐aminophenoxy)phthalonitrile (APN) with acid‐contained PEN (PEN? COOH) in the presence of CaCl₂. The chemical structure and molecular weight of PEN? CN were characterized by ¹H‐NMR, Fourier transform infrared spectroscopy, and Gel permeation chromatography. The synthesized PEN? CN had superior solubility in polar organic solvent and can be easily processed into thin films from the solutions of N‐methylpyrrolidone, dimethylsulfoxide, N,N′‐dimethylformamide, dimethylacetamide, and tetrahydrofuran. Compared with PEN? COOH, PEN? CN showed higher thermal stability with 5% weight loss temperatures (T_5%) up to 430°C. The glass transition temperature of PEN? CN was improved from 211 to 235°C measured by differential scanning calorimetry (DSC). In addition, it also exhibited excellent mechanical properties that Young's modulus reached to 3.5 GPa. Meanwhile, the effects of different aromatic amines and Lewis acid on the crosslinking behavior of PEN? CN were investigated by DSC. The results indicated that anhydrous Zinc chloride (ZnCl₂) was the best catalyst to lower the curing temperature among 2,6‐bis(4‐diaminobenzoxy) benzonitrile, 4,4‐diaminediphenyl sulfone, APN and ZnCl₂. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Thermomechanical behavior of poly(carborane–siloxane)s containing ?CB5H5C? cages

The thermomechanical spectra of two new carborane–siloxane polymers containing five-boron carborane cages in the backbones are reported and discussed. The polymers are the homopolymer, HO? [Si(CH₃)₂? CB₅H₅C? Si(CH₃)₂? O? ]_nH, and the random copolymer with 20 mole-% of the ten-boron meta-carborane analogue, ? [Si(CH₃)₂? CB₁₀H₁₀C? Si(CH₃)₂? O? ]. The mechanical spectra (～1 cps) were determined from ?180° → +625° → ?180°C (ΔT/Δl = 3.6°C/min for T > 25°C and 2°C/min for T < 25°C) using the semimicro thermomechanical technique, torsional braid analysis. In nitrogen, both polymers displayed secondary transitions at ?140°C. The glass transition (T_g) for the homopolymer was ?60°C and for the copolymer was ?52°C. The homopolymer had a melting point of +70°C. The copolymer was amorphous. The high-temperature stability in nitrogen of both polymers appeared to be identical; thermal stiffening commenced at 400°C, continued to 625°C, and resulted in materials that were typical of highly crosslinked resins. In air, the homopolymer began to stiffen catastrophically near 270°C, while the copolymer began to stiffen similarly nearly 50°C higher. The intrinsic elastomeric nature together with the thermomechanical results prompted further study of the copolymer. Thermomechanical cycling studies in nitrogen and air are reported for the copolymer. Some correlating TGA and DTA are also discussed.     

Synthesis and characterization of novel borosiloxane‐containing aromatic copolyimides with excellent thermal stability and low coefficient of thermal expansion

The properties of borosiloxane‐containing copolyimides with borosiloxane in the main chain and in the side chain were studied. Two series of borosiloxane‐containing copolyimides were synthesized by the reaction of 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (s‐BPDA ) and 2,3′,3,4′‐biphenyltetracarboxylic dianhydride (a‐BPDA ) with p ‐phenylenediamine (PDA ), 4,4′‐oxydialinine (4,4′‐ODA ) and different borosiloxane diamine monomers (BSiAs ). The synthesized borosiloxane‐containing copolyimides exhibited better solubility than borosiloxane‐free copolyimides and showed high glass transition temperatures (320–360 °C), excellent thermal stability (570–620 °C for T ₁₀), great elongation at break (10% ? 14%) and a low coefficient of thermal expansion (14–24 ppm °C^?1). More specifically, the copolyimides containing BSiA‐2 formed nano‐scale protrusions and the copolyimides containing BSiA‐1 formed micro‐scale protrusions. The contact angles of the copolyimides increased from 72° for neat copolyimide to 96° for 5% of borosiloxane in the main chain of the copolymer up to 107° for 10% of borosiloxane in the side chain of the copolymer. © 2017 Society of Chemical Industry     

Antiscaling properties of novel maleic‐anhydride copolymers prepared via iron (II) – chloride mediated ATRP

A class of maleic anhydride copolymers (YMR‐A series) with a narrow molecular weight distribution between 500–1500 and a polydispersity of 1.0–1.11 was obtained from n‐alkylacrylamide and maleic anhydride monomers via atom transfer radical polymerization. The monomer conversion reached about 71% corresponding to 1:4 [FeCl₂] to [SA] molar ratios for (AAH/MA) copolymer initiated by CPN whereas for the polymerization initiated by MCPN the conversion reached 51.9% under similar condition showing better performance of CPN initiator. Resultant polymers were characterized by means of ¹H‐NMR and ¹³C‐NMR. The inhibition behavior of these YMR‐A polymers against CaCO₃ and CaSO₄ was evaluated using static scale inhibition method. The inhibition efficiency on the calcium carbonate scale is much higher and even with 5 ppm dosage level the efficiency is around 99.33 % at pH 10.45 and temperature 70°C, where as for calcium sulfate scales the inhibition efficiency, is lower and 99.9% inhibition is observed at 7–9 ppm level. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39827.     

Charge transfer copolymerization and properties of isopropyl methacrylate with acrylonitrile and methacrylonitrile

Isopropyl methacrylate (IPMA) with Acrylonitrile (AN) and Methacrylonitrile (MAN) copolymers of different copositions were prepared at 60°C and 80°C, respectively, using a mixture of n-Butylamine (nBA) and carbon tetrachloride (CCl₄) in dimethyl sulphoxide (DMSO) as a charge transfer (CT) initiator. The percentage composition of the copolymers was established by elemental analysis. The copolymerization reactivity ratios were computed by the Kelen–Tudos method. In both the systems, IPMA was found to be more reactive; the copolymers sequence was random in nature. The copolymers were characterized by IR, ¹H-NMR, ¹³C-NMR spectroscopy and intrinsic viscosity measurements in dimethyl formamide (DMF) at 30±0.1°C. The thermal behavior of the AN-IPMA copolymers was studied by thermogravimetry (TG) in air. The thermal stability increased, with increasing AN content in the copolymer chain. The solubility parameter of AN-IPMA copolymer was evaluated by studying the intrinsic viscosity in different solvents. The solubility parameter of the copolymer was found to be 9.7 (cal/cc)^1/2.