Flame-Retardancy Improvement of Novel Styrene–Maleic Anhydride Based Copolymers

Brominated flame-retardants are one of the common and efficient compounds in producing flame retardant plastics and antimony trioxide is often used as a synergistic agent for halogenated flame-retardants. In this research, a new reactive flame retardant, maleated tetrabromobiphenol-A (MTBBA) crystals, has been introduced for the first time and its structure was fully characterized by high-field ¹H NMR and ¹³C NMR spectroscopy. The improvement in flame-retardancy effect of styrene–maleic anhydride copolymer by MTBBA and also their compounded samples with Sb₂O₃ was investigated as the main purpose in this work. Limiting oxygen indexes (LOI) for the neat terpolymers and the compounded samples were measured by flammability tests. Also thermal gravimetry analysis (TGA) and differential scanning calorimetry (DSC) were applied in order to study thermal behavior of the samples. The results of thermal analysis were used to observe the effect of insertion of this novel monomer into the copolymer chain in comparison with styrene–maleic anhydride copolymer.     

Synthesis and photophysical behavior of a water-soluble fluorescein-bearing polymer for Fe<Superscript>3+</Superscript> ion sensing

An acrylic monomer bearing xanthene group, acryloylfluorescein (Ac-Flu) was synthesized from fluorescein and acryloyl chloride in the presence of triethylamine in dry dichloromethane (CH₂Cl₂) at room temperature. The synthesized Ac-Flu was identified by IR, MS and ¹HNMR spectra. Copolymer of Ac-Flu and acrylamide (AM) was synthesized with thermal initiator and it was characterized by the method of IR, UV–Vis and DSC. The photophysical behaviors of Ac-Flu and its copolymer were explored by recording the fluorescence spectra in solution, solid state and film in detail. In addition, the ability of the copolymer to detect different metal cations (Mn²⁺, Fe³⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺) in aqueous solution was investigated. The results showed that poly(Ac-Flu-co-AM) had a good linear response between the logarithm of concentration of Fe³⁺ (lg[Fe³⁺]) against the relative fluorescence intensity for Fe³⁺ concentration. The results suggest that this copolymer may offer potential as a reusable polymer sensor for Fe³⁺ ion in aqueous solution.     

Semicontinuous thermal bulk copolymerization of styrene and maleic anhydride: Experiments and reactor model

Thermal bulk copolymerization of styrene (St) and maleic anhydride (MAH) has been carried out at 110–130°C and up to around 55 wt % conversion in a stirred tank reactor with an anchor impeller to prepare the random copolymer of St–MAH (R-SMA). A series of experiments in semicontinuous monomer adding process were done to investigate the effects of operating condition on monomer conversion, copolymer composition, and its uniformity. It has been shown that a random copolymer with constant composition can be obtained by semicontinuous copolymerization. A reactor model was developed to simulate the copolymerization processes. The numerical method in which the gel effect on the copolymerization is incorporated has exhibited excellent agreement between the model calculation and the experimental data. However, when using the assumption that (1) k₂₂ = 0; (2) k₂₁[M₁] ≫ k₁₂[M₂]; and (3) (R₁/2k_t)^1/2 is a constant, an analytical solution to the model was found to be available also. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1905–1912, 1998     

Synthesis of Graft Copolymers and Their Preliminary Use as a Compatibilizer in Polymer Solar Cells

Poly(p-xylylene)-graft-poly(butylacrylate-g-fullerene) or PPX-g-PBAFu was synthesized by using Wessling route and atom transfer radical addition (ATRA) techniques. The graft copolymers were used as a compatibilizer in the bulk heterojunction (BHJ) polymer solar cells of poly(3-hexylthiophene) (P3HT) and fullerene (C₆₀). The results from AFM micrographs showed that the phase size of P3HT and the aggregated C₆₀ in the blended system was decreased from 300 to 30 nm after adding the copolymer (20 pph). Furthermore, the efficiencies of the BHJ cells from J-V curve were remarkably increased five times after adding the copolymer.     

Synthesis of graft copolymers based on polyphenylene xylylene and fullerene grafted polystyrene

Graft copolymers containing poly(phenylene xylyene) (PPX) backbone and polystyrene fullerene (PSFu) grafting chains (PPX‐g‐PSFu) were prepared by using a purposed synthetic route comprising a combination of reaction mechanisms namely the modified Wessling route, an iniferter polymerization, and an atom transfer radical addition (ATRA). The monomer was first prepared by reacting dichloroxylene with tetrahydrothiophene. After that the monomer was polymerized in a sodium hydroxide solution to provide a polymer precursor. Subsequently, the polymer precursor was modified by reacting it with a dithiocarbamate (DTC) compound. The macroiniferter was obtained and then copolymerized with styrene and chloromethylstyrene via an iniferter polymerization. Finally, the graft copolymer was reacted with fullerene through an ATRA technique to attach the C60 groups onto the graft copolymer molecule. The products obtained from each of the steps were characterized by using various techniques including Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry, UV–visible spectroscopy, and thermal gravimetric analysis. The aforementioned results suggest that the graft copolymers were prepared. The grafting yield and grafting efficiency were found to increase with the monomers concentration and the amount of DTC used. Some homopolymer contaminants also occurred but those could be minimized and subsequently removed by extraction with selective solvents. These graft copolymer products might be used for the development of a bulk heterojunction polymer solar cell. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrochemical synthesis and characterization of poly (o-amino benzyl alcohol) and poly (o-amino benzyl alcohol-co-o-anisidine)

In this study; poly (o-amino benzyl alcohol) and poly (o-amino benzyl alcohol-co-o-anisidine) copolymer films were electrochemically synthesized by cyclic voltammetry technique on the platinum electrode. The synthesis of copolymer films was achieved in various monomers feed ratio (o-amino benzyl alcohol: o-anisidine; 8:2, 1:1, 2:8) of o-amino benzyl alcohol and o-anisidine. Different solution types were tested in aqueous and non-aqueous media, especially during the synthesis process, as the electrolyte medium. As a result of the experiments, it was determined that sulfuric acid solution was the most suitable solution for both homopolymer and copolymer film growth. Homopolymer and copolymer samples were characterized by FT-IR, cyclic voltammetry (CV), SEM, digital images and TGA/DTA techniques. The CV, SEM and digital images results indicated that the solution which has high ratio of monomer is more effective in copolymer film synthesis mechanism. TGA results showed that the 1:1 copolymer film had higher thermal stability than the films at other monomer ratios. Also, electrochemical studies exhibited that the copolymer film in 1:1 ratio is partially more electrochemically stable than other copolymer films.     

Effect on thermal,mechanical, and biodegradable properties of plasma-treated fish scale powder/linear low-density polyethylene polymer composite films

In the present work, we report the effect of low-temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low-density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties. It was observed that the tensile strength decreased with the increased loading content of CFSP, and 1% CFSP/LLDPE exhibited the highest tensile strength. To study the effect of low-temperature plasma treatment, 1% CFSP/LLDP polymer composite with high tensile strength was plasma treated with O₂ and SF₆ gas before blow film extrusion. The 1% CFSP/LLDPE/SF₆-extruded blown films showed increased thermal decomposition, crystallinity, tensile strength, and modulus. This may be due to the effect of crosslinking by the plasma treatment. The maximum thermal decomposition rate, crystallinity %, tensile strength, and modulus obtained for 1% CFSP/LLDPE/SF₆ film were 500.02°C, 35.79, 6.32 MPa, and 0.023 GPa, respectively. Furthermore, the biodegradability study on CFSP/LLDPE films buried in natural soil for 90 days was analyzed using x-ray fluorescence. The study showed an increase in phosphorus and calcium mass percent in the soil. This is due to the decomposition of the hydroxyapatite present in the CFSP/LLDPE biocomposite.     

一种含氟共聚物乳液的制备及其性能

通过制备一种含有全氟壬烯基的含氟共聚物乳液,并考察其性能,研究了含氟单体对共聚物乳液性能的影响。以K2S2O8为引发剂,丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)和全氟壬烯基烯丙基醚(PFNAE)为共聚单体,采用半连续乳液聚合的方法,制备了带蓝色荧光的含氟乳液。用傅里叶红外(FT-IR)、接触角、差示量热扫描(DSC)和热重(TG)分析等手段对制备的PFNAE-BA-MMA共聚物(PBM)结构和性能进行表征。结果表明:引入含氟单体后,聚合物的疏水性、热稳定性、玻璃化温度(Tg)都有提高。水在含氟共聚物上的接触角随含氟单体用量的增加而增大,当PFNAE占单体总质量的25%时,水的接触角为94.9°;当PFNAE占单体总质量的20%时,共聚物在221℃开始分解,429.5℃分解完全,该共聚物Tg为8.5℃。PFNAE-BA-MMA共聚物具有一定的拒水性和良好的热稳定性。     

Synthesis and application of new fullerene derivative

A novel fullerene–maleic anhydride copolymer is synthesized via radical polymerization. It is soluble in polar solvents such as water, dimethyl sulfoxide, tetrahydrofuran, and so forth. The product is characterized by FTIR, UV–visible, and GPC. Transmission electron microscope analysis shows that it presents an ideal spherical shape in water with an average particle diameter of about 36 nm. Four‐ball tests show that the addition of a certain concentration of the fullerene copolymer to the base stock (2 wt % triethanolamine and 0.5 wt % Alkylpolyoxyalkylene Phosphate Zinc (OPZ) aqueous solution) can effectively raise the load‐carrying capacity (P_B value) and raise the antiwear ability. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2182–2185, 2005     

Synthesis,Characterization, Reactivity Ratio and Photo Crosslinking Properties of the Copolymer of 4-Cinnamoyl Phenyl Methacrylate with Butyl Methacrylate

Copolymers of 4-cinnamoyl phenyl methacrylate (4-CPMA) and n-butyl methacrylate (BMA) were prepared in a methyl ethyl ketone (MEK) solution with benzoyl peroxide (BPO) as an initiator at 70°C. They were characterized with UV, IR, ¹H-NMR, ¹³C-NMR, TGA, DSC and gel permeation chromatography. Copolymers were prepared by using different feed ratio of monomers. The monomer reactivity ratios determined by the method of Kelen-Tudos (K-T) were r₁ (CPMA) = 2.32, r₂ (BMA) = 0.56. The glass transition temperature of the copolymer shows a single Tg indicating the formation of random copolymer for all of the monomer feed composition. Thermogravimetric analysis in air has shown that the initial decomposition temperature of the copolymer was above 220°C. The photocrosslinking properties of the copolymer were examined by UV irradiation with polymer film.     

Synthesis and characterization of poly[4‐(2‐thiazolylazo)phenyl methacrylate]‐co‐poly(methyl methacrylate)

A new methacrylic monomer, 4‐(2‐thiazolylazo)phenylmethacrylate (TPMA) was synthesized. Copolymerization of the monomer with methyl methacrylate (MMA) was carried out by free radical polymerization in THF solution at 70 ± 0.5°C, using azobisisobutyronitrile (AIBN) as an initiator. The monomer TPMA and the copolymer poly(TPMA‐co‐MMA) were characterized by Fourier transform infrared (FTIR), ¹H nuclear magnetic resonance (NMR), and elemental analysis methods. The polydispersity index of the copolymer was determined using gel permeation chromatography (GPC). Thermogravimetric analysis (TGA) of the copolymer performed in nitrogen revealed that the copolymer was stable to 270°C. The glass transition temperature (T_g) of the copolymer was higher than that of PMMA. The copolymer with a pendent aromatic heterocyclic group can be dissolved in common organic solvents and shows a good film‐forming ability. Both the monomer TPMA and the copolymer poly (TPMA‐co‐MMA) have bright colors: orange and yellow, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2152–2157, 2007     

Investigation of the Properties of Phthalocyanine Resin Containing Bismaleimide Groups

A bisphthalonitrile monomer containing bismaleimide groups was synthesized using 4,4′-bismaleimidodiphenylmethane and 4-aminophenoxyphthalonitrile. The structure of the monomer was confirmed by elemental analysis and IR spectroscopy. With this monomer, a phthalocyanine resin containing bismaleimide groups was obtained by catalytic thermal polymerization. The structure of the resin was confirmed by IR spectroscopy. The characteristic absorption peak of nitrile groups at 2200cm^-1 disappeared in the IR spectra, showing that polymerization of monomer was complete. Thermogravimetry of the resin in air and N₂ was investigated; the results show that this resin has excellent thermal and thermo-oxidative stabilities, and a high char yield in nitrogen (82·7%). In addition, a monomer solution in dimethylacetamide was flow-coated on a glass strip to form a resin film. The adhesion between film and glass strip was firm, and the resin film had strong resistance to saturated alkali solution. A solubility test showed that the resin possessed good chemical inertness. Copper and aluminium strips were bonded using monomer solution. The single-lap shear strength of samples was tested after curing. The results demonstrated that the adhesion between resin and copper strips was stronger than with aluminium strips. The resin can be used as a heat-resistant adhesive. © of SCI.     

Facile electrosynthesis of nitro-group-substituted oligopyrene with bicolored emission

Nitro-group-substituted oligopyrene (ONP) film with fairly high electrical conductivity (1.25 × 10⁻¹ S cm⁻¹) and good thermal stability was electrochemically synthesized by direct anodic oxidation of its monomer 1-nitropyrene (NP) in boron trifluoride diethyl etherate (BFEE). The oxidation potential of NP in this medium was determined to be 1.12 V vs. SCE, which was lower than that in acetonitrile +0.1 mol L⁻¹ Bu₄NBF₄ (1.27 V vs. SCE). ONP films obtained from this medium showed good redox activity and structural stability in both BFEE and concentrated sulfuric acid. Fourier transform infrared spectra and theoretical calculations showed that the electropolymerization of the NP monomer mainly occurred at the C(3), C(6) and C(8) positions. The fluorescence spectra suggested that soluble ONP emits strong blue or green fluorescence when excited at 402 nm or 504 nm, respectively. Scanning electron microscopy showed that highly crystalline nitro-group-substituted oligopyrene was formed on the electrode surface. All these results indicate that as-prepared ONP film has many potential applications in various fields.     

乳化环氧改性的丙烯酸系乳液室温固化体系

将乙二醇二缩水甘油醚分散在水中制成环氧化合物乳液,并以其为交联剂,用以对丙烯酸系单体/胺基单体乳液共聚物的改性,制成了双组分室温固化乳液涂料。研究了乳化剂种类和胺基单体用量对聚合稳定性的影响,结果表明,若采用p 壬基酚聚氧化乙烯醚硫酸钠为乳化剂,且胺基单体用量低于单体总量2 5%时,可以制得稳定的带胺基的共聚物乳液。将丙烯酸系共聚物乳液和环氧乳液复合并在室温下干燥成膜,通过对聚合物膜的DSC和力学性能测试均表明,双组分体系在成膜过程中发生了交朕反应,而未加环氧化合物的单组分聚合物乳液成膜时则不发生交联。     

Preparation and properties of cationic membranes obtained by radiation grafting of methacrylic acid onto PTFE films

Cationic membranes were prepared by direct radiation grafting of methacrylic acid (MAA) onto poly(tetrafluoroethylene) (PTFE) films followed by alkaline treatment to confer ionic character in the graft copolymer. The complete inhibition of homopolymerization of MAA by using ammonium ferreous sulfate (Mohr's salt) failed. However, the addition of 0.5 wt % FeCl₃ to the monomer solution effectively inhibited the homopolymerization process and higher grafting yield was obtained. It was found that the graft polymerization proceeded successfully in presence of methanol/water mixture (30/70 wt %), and much higher degrees of grafting were obtained as compared with those in the presence of other diluents used here. The influence of irradiation atmosphere (air, N₂ gas, and vacuum) on the grafting process was investigated. The dependence of the grafting rate on MAA concentration was found to be of orders 2.9 and 0.72 in the presence of 0.5 wt % Mohr's salt or 0.5 wt % FeCl₃, respectively. This grafting system proceeds by the front mechanism. Investigation of mechanical properties, electrical conductivity, and swelling behavior of the grafted films revealed that such a copolymer could be acceptable in practical use as a cation-exchange membrane.     

A regioregular polythiophene–fullerene for polymeric solar cells

In this article, we present the synthesis and characterization of a new thiophenic copolymer bearing the C₆₀ fullerene directly linked to the end of a hexamethylenic side chain. This copolymer was prepared with good yield using a simple and straightforward post‐polymerization functionalization procedure applied on a soluble regioregular polymeric precursor obtained by regiospecific organometallic coupling. Copolymer structural and photophysical properties were investigated by gel permeation chromatography, thermal analysis (DSC and TGA), NMR, IR, UV–Vis, and atomic force spectroscopy. The double‐cable copolymer possesses good solubility in common organic solvents, high filmability, thermal stability, and low segmental aggregation tendency. It was tested as a photoactive layer in a polymeric solar cell showing a power conversion efficiency under 100 mW cm^?2 AM 1.5 illumination higher than 4%, more than that of the reference cell made with the conventionally used P3HT/PCBM blend. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42121.     

Curing behavior and properties of benzoxazine‐co‐self‐promoted phthalonitrile polymers

A new high‐performance copolymer was successfully obtained via concerted catalysis polymerization of mono‐functional benzoxazine (P‐a) and self‐promoted 4‐aminophenoxy phthalonitrile (4‐APN) monomers. The FTIR and DSC curves of the P‐a/4‐APN in different blend ratios suggested that the monomer blends can be completely cured without the addition of curing additive. The P‐a/4‐APN copolymers were cured at relatively lower curing temperatures and time. The TGA curves revealed that the P‐a/4‐APN copolymers have good thermal stability in terms of T₅, T₁₀, and char yield. A gradual increase in the glass transition temperature (T_g) values and decline were seen in the storage modulus as the loading of 4‐APN was increased from 10 to 30 wt % in the copolymer. The SEM analyses showed that copolymer's fracture surface is dendritic, showing the stress has been dispersed to a certain extent. The study revealed that the poly(P‐a/4‐APN) copolymer have much better thermal stabilities than the poly(P‐a), and the prepared copolymer can be used as a high‐performance thermosetting resin. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46578.     

Copolymerization of styrene and ethylene with mononuclear and dinuclear half-titanocenes

With mononuclear half-titanocenes such as CpTiCl₃, IndTiCl₃, and Me₅CpTiCl₃, as well as the constrained geometry catalyst (CGC) and a new dinuclear hexamethyltrisiloxanediylbis(cyclopentadienyltitanium trichloride) (TSDT), the copolymerization of styrene and ethylene was examined. The thermal properties and structure of copolymerization products were investigated with differential scanning calorimetry and ¹³C-nuclear magnetic resonance. In addition, the raw polymer was separated into homopolymer and copolymer with an extraction method and cross fractionation chromatography. With the above analysis, it was concluded that the raw polymer obtained with CpTiCl₃ and IndTiCl₃ was a mixture of syndiotactic polystyrene and polyethylene homopolymers with 10–30 wt % copolymer, whereas that produced by Me₅CpTiCl₃ and TSDT was a homopolymer mixture with a negligible amount of copolymer. Only CGC produced the copolymer of styrene and ethylene perfectly. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2187–2198, 1998     

Viscoelastic properties and coating performance of water-soluble acrylic copolymers crosslinked with melamine resin

Acrylic copolymers with different amounts of carboxyl and hydroxyl groups for obtaining practical performance of melamine-cured acrylic coatings was investigated. Property testing results indicated that glass transition temperature (T_g) and shear modulus increased, and molecular weight between crosslinks (M_c) decreased with the increase of hydroxyl and carboxyl number in the acrylic copolymers. The degree of crosslinks influenced the resistance to solvent and chemicals at a lower baking temperature. Compared with acrylic acid, itaconic acid as a carboxyl monomer was more effective in inducing a lower baking schedule. The water-soluble acrylic copolymer, which is neutralized with triethylamine, consists of 20 wt % methylmethacrylate, 55 wt % buthylacrylate, 15 wt % hydroxyethyl methacrylate, and 10 wt % itaconic acid. The copolymer showed higher crosslinks when cured with methoxymethyl melamine formaldehyde resin under a relatively lower baking schedule at 135°C for 30 min. It also has excellent solvent and chemical resistance. This coating film has a T_g value of 39°C, modulus of 2 × 10⁸ dyne/cm² in the rubbery state, and M_c value of 464. Also the acrylic copolymer films with M_c < 900 have good properties for solvent, acid, and alkali resistance. © 1995 John Wiley & Sons, Inc.     

Influence of film structure on mobilities of charge carriers in conducting polymers

Two sorts of poly(3-hexylthiophene) (PHT) films with the same chemical compositions were prepared, and their electrochemical, spectroscopic, and transport properties were studied with a special interest in a possible influence of film structure on mobilities of charge carriers. One of the PHT films was electrochemically synthesized using 3-hexylthiophene as a monomer (as-grown film) and the other was obtained by dissolving the as-grown film in chloroform and then casting the polymer solution (cast film). A clear difference was observed in the mobility versus doping level plot between the two sorts of PHT films, demonstrating that the difference is caused only by a distinction in film structure. An initial decreasing feature of the mobility plot observed for the cast films was accounted for in terms of swelling of the films at an early stage of doping.