Synthesis of poly (p-methylstyrene) - graft-poly (oxyethylene) and application as a polymeric surfactant in emulsion polymerization

Poly(p-methylstyrene)-graft-poly(oxyethylene) copolymers were prepared from p-methylstyrene and æ-hydroxy-ω-methyl-poly(oxyethylene) using a ‘grafting on to’ technique. A total of 10 copolymers were synthesized varying in the hydrophobic back bone chain lengths, hydrophilic branch lengths and frequency of branches. The stabilizing efficiency of these amphipathic copolymers was studied in the emulsion polymerization of styrene. Using the number, size and size distribution of the particles as the criterion of stability, it was found that the polyoxyethylene (PEO) chain length is not as crucial for stability as the availability of the backbone for anchoring. A change in the backbone chain length (from M?_n = 1000 to 24000) with the same percent PEO had no effect on the outcome of the reaction: the latices stabilized to the same number of particles of the same size.     

Organic sulfur compounds as initiators of polymerization. VII. Polymerization of methyl methacrylate by N-[(p-benzoyl)benzenesulfonyl]benzenesulfonamide

The photopolymerization of methyl methacrylate in bulk using N-[(p-benzoyl)benzenesulfonyl]benzenesulfonamide as a photoinitiator was studied. A kinetic study of the photopolymerization showed that the rate of polymerization is proportional to the square root of the photoinitiator concentration. The decomposition of a sulfur–nitrogen bond and the obtained radicals are suggested to be responsible for the initiation of polymerization. The influence of the photoinitiator on the molecular weight was also studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2083–2086, 1998     

Reactive surfactants in heterophase polymerization. VI. Synthesis and screening of polymerizable surfactants (surfmers) with varying reactivity in high solids styrene—butyl acrylate—acrylic acid emulsion polymerization

Several polymerizable surfactants (surfmers) have been used in the semi-continuous emulsion copolymerization of styrene, butyl acrylate, and acrylic acid. Three of the (anionic) surfmers (sodium 11-crotonoyl undecan-1-yl sulfate, sodium 11-methacryloyl undecan-1-sulfate, and sodium sulfopropyl tetradecyl maleate) were prepared in house with purities between 53 and 82%. Physicochemical properties such as the critical micelle concentration, the adsorption isotherm, and the specific adsorption area were determined. The surfmers were then used with constant addition profiles in semicontinuous reactions, and the instantaneous conversions of the main monomers determined. The particle size, amount of coagulum, surface tension, and stability against electrolyte solutions of the latices were evaluated. Films were cast of some of the latices, and the visual appearance and water adsorption were assessed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 183–1820, 1997     

Preparation of compatible blends of poly(methyl methacrylate) used in dentistry with a reactive terpolymer containing maleic anhydride and their thermomechanical characterization

This study focuses on the preparation of compatible blends with the poly(methyl methacrylate) (PMMA) using a reactive terpolymer maleic anhydride–styrene–vinyl acetate (MA–St–VA). In the first series of experiments, binary blends of the PMMA and the MA–St–VA terpolymer have been prepared in tetrahydrofurane. The PMMA and the MA–St–VA terpolymer formed the compatible blends. The effects on thermomechanical properties of MA–St–VA terpolymer ratio in the blends were studied. The glass transition temperatures (T_g), thermal expansion coefficient (α), and other thermomechanical parameters for the blends have been established by TMA method and the compatibility of two polymers has been evaluated by these TMA parameters. The addition of MA–St–VA terpolymer to PMMA made a plasticizing effect on PMMA. This effect regularly changed with the increasing of the terpolymer in the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 363–367, 2006     

Poly[(maleic acid)-co-styrene]–platinum complex; a catalyst for the hydrogenation of methyl formate

Coordinate bonds form between oxygen and platinum atoms in crosslinked poly[(maleic acid)-co-styrene]–platinum complex according to FTIR and XPS measurements. The complex is demonstrated to be an active and selective catalyst for the hydrogenation of methyl formate under mild conditions (25°C, 1 atm H₂). Methyl formate can be converted selectively to methanol in 82·6% yield within 6h at a COOH/Pt mole ratio of 17·85 in the complex with n-propanol as the solvent. The catalyst exhibits high stability, with turnover number (mol of methyl formate converted/mol of platinum) of the catalyst reaching 1064 within 48 h.     

Entry in emulsion polymerization using a mixture of sodium polystyrene sulfonate and sodium dodecyl sulfate as the surfactant

A mixture of sodium polystyrene sulfonate (NaPSS) and anionic surfactant, sodium dodecyl sulfate (SDS), was used as the emulsifier in the emulsion polymerization of styrene at 60 °C. The latexes prepared were stable, bearing the better resistance to the addition of electrolyte, and have the larger values in particle size and the higher polymerization rates than those counterparts prepared using SDS only. The NaPSS was prepared by a series of process: a concentrated cyclohexane solution of an anionically polymerized polystyrene (PS) was sulfonated with sulfuric acid at 80 °C, and then neutralized and purified through dialysis. The data of average polymer number per particle (n_p) were found useful in investigating the surfactant content effect on the entry of radicals into particles, where the latex particle size plays an important role.     

Synthesis and characterization of poly(methyl methacrylate‐co‐maleic anhydride) copolymers and its potential as a compatibilizer for amorphous polyamide blends

Poly(methyl methacrylate‐co‐maleic anhydride) copolymers (MMA‐MA) have been synthesized by solution method, using toluene as solvent and benzoyl peroxide as initiator. The MMA‐MA copolymers were characterized by size exclusion chromatography, Fourier transforms infrared spectroscopy (FTIR), and titration. It was found that the modified polymerization procedure used in this work was more effective in controlling the molecular weight when adding different amounts of maleic anhydride (MA) than procedures previously used. In spite of the significant difference in reactivity ratios between MMA and MA, up to 50% of the MA added to the reactor was incorporated into the copolymer. The evidences for reactions of the MA groups of the MMA‐MA copolymer with the amine end groups of the amorphous polyamide (aPA) during melt blending was obtained by rheological measurements. In this work, the molecular weight and the content of MA reactive functional groups in the MMA‐MA copolymer were varied independently and its effects on the interaction with aPA were studied. It was observed that a compromise between molecular weight and the level of reactive functional group of the compatibilizer should be sought to improve the compatibilization of the polymer systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Curing kinetics and structural changes of a of di[(N‐m‐acetenylphenyl) phthalimide] ether/[(methyl) diphenylacetylene] silane copolymer

Differential scanning calorimetry, Fourier transform infrared (FTIR) spectroscopy, and ¹³C‐NMR were used to characterize the curing kinetics and structural changes of a copolymer of di[(N‐m‐acetenylphenyl) phthalimide] ether (DAIE) and [(methyl) diphenylacetylene] silane (MDPES). The results show that the apparent activation energy (E) and reaction order (n) calculated according to the Kissinger method were nearly the same as those calculated according to the Ozawa method. E was 160.4 kJ/mol and n was 0.96 with the Kissinger method, and E was 158.1 kJ/mol and n was 0.95 with the Ozawa method. The FTIR and solid‐state ¹³C‐NMR results also indicate that with increasing curing temperature, the peaks assigned to Si? H and C?C bonded to phenylene carbons decreased, broadened, and finally vanished, whereas the peaks assigned to the C?C carbons and phenyl carbons increased and broadened. Crosslinking reactions in the curing of the DAIE/MDPES copolymer were possible due to the hydrosilylation reaction and the Diels–Alder reaction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2126–2130, 2006     

Synthesis of a biocompatible fluorinated multiblock copolymer surfactant for water-in-fluorocarbon droplets and its application in droplet digital polymerase chain reaction

Droplet digital polymerase chain reaction (ddPCR) technology has attracted considerable attention in recent years. A multiblock surfactant based on perfluompolyethers (PFPE) has been widely used in droplet-based microfluidics and is known to provide high droplet stability and biocompatibility. We developed a multiblock copolymer surfactant synthesized by adjusting the proportions of the intermediates to enhance the stabilities of droplets at high temperatures. The surfactants were synthesized via amidation reactions that coupled the PFPE and diamine polyethylene glycol (PEG), and the introduction of triethylamine, as a catalyst, made the reaction more efficient. The as-synthesized surfactants were used to generate water-in- fluorocarbon (W/F) droplets with a microfluidic device and a ddPCR device was used to evaluate the performance of the droplets. When the molar ratio (PFPE-PEG:PFPE-PEG-PFPE) was 2:1 and the concentration reached 2 wt%, the droplets showed good thermal stability. Surfactant showed the best performance, lowering the interfacial tension to 2.5 mN/m, when it's critical micelle concentration (CMC) exceeded 50 mg/L. Furthermore, the use of an alkaline solution (pH = 9 – 10) as the washing buffer, improved the biocompatible of the surfactant. When applied to the detection of λDNA, the limit of detection was 0.52 copies/μL. The as-synthesized surfactants showed promise in generating biocompatible and thermally stable droplets and providing a new surfactant option for future ddPCR technology.     

Synthesis and application of 2‐acrylamido‐2‐methyl propane sulfonic acid/acrylamide/N,N‐dimethyl acrylamide/maleic anhydride as a fluid loss control additive in oil well cementing

Using 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS), acrylamide (AM), N,N‐dimethyl acrylamide (NNDMA), and maleic anhydride (MA), a new dispersive type fluid loss control additive (FLCA) AMPS/AM/NNDMA/MA (PANM) was synthesized by free radical aqueous solution copolymerization, and the new FLCA could be used without dispersant existing in the cement. The optimal PANM (OPANM) was obtained under the optimum reaction conditions: mole ratio of AMPS/AM/NNDMA/MA = 4/2.5/2.5/1, monomer concentration = 32.5%, amount of (by weight of monomer) ammonium persulfate/sodium bisulfate = 1.0%, pH value = 4, and temperature = 40°C. The synthesized copolymer OPANM was identified by FTIR analysis. The evaluation results show the OPANM has excellent dispersing power, fluid loss control ability, thermal resistant, and salt tolerant ability. The OPANM was even stable when the temperature was below 300°C proved by TG analysis. The thickening time of the slurry containing the synthesized additive reduces as the temperature increases. The copolymer OPANM is expected to be an excellent FLCA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Use of silane agents and poly(propylene‐g‐maleic anhydride) copolymer as adhesion promoters in glass fiber/polypropylene composites

Two organofunctional silanes and a copolymer were used to increase the interfacial adhesion in glass fiber polypropylene (PP) reinforced composites. The performance of the coupling agents was investigated by means of mechanical property measurements, scanning electron microscopy (SEM), and dynamic mechanical analysis. The increased adhesion between the glass fibers and PP matrix observed with SEM resulted in an improvement of the mechanical and dynamic mechanical properties of the composites. Coupling achieved with the copolymer poly(propylene‐g‐maleic anhydride) (PP‐g‐MA) proved to be the most successful compared with 3‐aminopropyltrimethoxysilane and 3‐aminopropyltriethoxysilane. The combination of PP‐g‐MA with the silanes resulted in further property improvements because of the ability of the MA groups to react with the amino groups of the silanes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 701–709, 2001     

Synthesis of a maleic anhydride grafted polypropylene–butadiene copolymer and its application in polypropylene/styrene–butadiene–styrene triblock copolymer/organophilic montmorillonite composites as a compatibilizer

A maleic anhydride grafted propylene–butadiene copolymer (MPPB) was prepared. Fourier transform infrared spectroscopy and ¹H‐NMR results indicate that the maleic anhydride molecules reacted with the double bond in the butadiene unit of the propylene–butadiene copolymer (PPB), and the grafting percentage increased with the butadiene content in the initial copolymer. The gel permeation chromatography results show that the introduction of butadiene in the copolymer prevented the degradation of PPB. The MPPB was applied in polypropylene (PP)/styrene‐butadiene‐styrene triblock copolymer (SBS)/organophilic montmorillonite (OMMT) composites as a compatibilizer. In the presence of 10‐phr MPPB, the impact strength of the composite was improved by about 20%. X‐ray diffraction patterns indicated the formation of the β‐phase crystallization of PP in the presence of MPPB, and a significant decrease in the spherulite size was observed. Transmission electron microscopy (TEM) images showed that the OMMT was better dispersed in the matrix upon the inclusion of MPPB. A better distribution of the rubber phase and a rugged fracture surface were observed in the scanning electron microscopy images as the MPPB proportion was increased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of a novel polymerizable surfactant and its application in the emulsion polymerization of vinyl acetate,butyl acrylate,Veova 10, and hexafluorobutyl methacrylate

A novel anionic, polymerizable fumaric surfactant (surfmer) was synthesized. The chemical structure of the surfactant was confirmed with ¹H‐NMR, IR, and mass spectrometry. The surfmer was then used with constant addition profiles in the semicontinuous polymerization of vinyl acetate, butyl acrylate, Veova 10, and hexafluorobutyl methacrylate. The particle size, amount of coagulum, and stability against electrolytes and freezing/thawing were evaluated. Films were cast from latices; then, photographs were taken of the films after immersion in water for days, and the water adsorption was assessed. As a reference, an unreactive surfactant (sodium dodecyl sulfate) was also used for the polymerization. Compared with sodium dodecyl sulfate, the surfmer behaved much better with respect to the stability of the latices and the water sensitivity of the films. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

The use of dilute acetic acid for butyl acetate production in a reactive distillation: Simulation and control studies

The recovery of dilute acetic acid, which is widely found as a by-product in many chemical and petrochemical industries, becomes an important issue due to economic and environmental awareness. In general, separation of acetic acid in aqueous solution by conventional distillation columns is difficult, requiring a column with many stages and high energy consumption. As a result, the primary concern of the present study is the application of reactive distillation as a potential alternative method to recover dilute acetic acid. The direct use of dilute acetic acid as reactant for esterification with butanol to produce butyl acetate in the reactive distillation is investigated. Simulation studies are performed in order to investigate effect of the concentration of dilute acetic acid and key process parameters on the performance of the reactive distillation in terms of acetic acid conversion and butyl acetate production. In addition, three alternative control strategies are studied for the closed loop control of the reactive distillation. The control objective is to maintain the butyl acetate in a bottom product stream at the desired purity of 99.5 wt%.     

A new initiating system based on [(SiMes)Ru(PPh3)(Ind)Cl2] combined with azo-bis-isobutyronitrile in the polymerization and copolymerization of styrene and methyl methacrylate

The homopolymerization and copolymerization of styrene and methyl methacrylate, initiated for the first time by the combination of azo-bis-isobutyronitrile (AIBN) with [(SiMes)Ru(PPh₃)(Ind)Cl₂] complex. The reactions were successfully carried out, on a large scale, in presence this complex at 80 °C. It was concluded from the data obtained that the association of AIBN with the ruthenium complex reduces considerably the transfer reactions and leads to the controlled radical polymerization and the well-defined polymers.     

Amine‐modified poly(vinyl alcohol) as a novel surfactant to modulate size and surface charge of poly(lactide‐co‐glycolide) nanoparticles

Poly(lactide‐co‐glycolide) (PLGA) nanoparticles (NPs) represent a promising tool for effective delivery of biomacromolecules, thanks to their biodegradability and biocompatibility properties. PLGA NPs are often synthesized by the emulsion‐solvent evaporation method and poly(vinyl alcohol) (PVA) represents one of the most commonly used surfactants. Although PVA‐mediated synthesis of PLGA NPs is effective in tailoring NP size and stability, the resulting negative surface charge can prevent both endosomal escape and biomacromolecule release in cell cytosol. To overcome this limit, a novel amino‐modified PVA (amino‐PVA) surfactant with a cationic charge was synthesized and its potential for the formulation of PLGA NPs was investigated. In either single (oil‐in‐water) or double (water‐in‐oil‐in‐water) emulsion synthesis, different mixtures of PVA and amino‐PVA were studied, by monitoring their effects on NP size and surface charge. Optimized properties were obtained with a combination of 0.975% (w/v) of PVA with 0.025% (w/v) of amino‐PVA. This formulation was further investigated for degradation properties and cytocompatibility. High stability and low cytotoxicity make the system promising for the encapsulation and release of hydrophilic drugs and biomacromolecules. © 2016 Society of Chemical Industry     

N-[2-(8-heptadecenyl)-4,5-dihydro-1H-imidazole-1-ethyl]-2-bromoisobutyramide as initiator for atom transfer radical polymerization (ATRP) and surface-initiated ATRP of methyl methacrylate on iron

N-[2-(8-heptadecenyl)-4,5-dihydro-1H-imidazole-1-ethyl]-2-bromoisobutyramide (IEB) was synthesized and characterized by elemental analysis, FT-IR, and ¹H NMR. It had been successfully used as a bidentate initiator for the ATRP of methyl methacrylate with CuBr/2,2′-bipyridine as the catalyst, and N,N-dimethylformamide as the solvent at 70 °C. The kinetics was first order in monomer and the number-average molecular weight of the polymer increased linearly with the monomer conversion, indicating the ‘living’/controlled nature of the polymerization. The polymerization reached high conversions producing polymers with a low molecular weight distribution ( M _w/M _n = 1.319). The obtained poly(methylmethacrylate) (PMMA) functionalized with 2-(8-heptadecenyl)-4,5-dihydro-1H-imidazoleyl and ω-Br as the end groups were characterized by FT-IR spectroscopy. They can be used as macroinitiators for chain extension reaction. Then, PMMA coatings were grafted from iron substrates by surface-initiated ATRP from a surface-bound IEB initiator. The EIS measurements confirmed the successful grafting of the polymer coatings. Greatly improved short-term anticorrosive properties for PMMA-modified electrodes were demonstrated by substantially increased resistance of the film for a period of 24 h as compared to bare iron.     

Preparation of a poly(L-lactide-co-caprolactone) copolymer using a novel tin(II) alkoxide initiator and its fiber processing for potential use as an absorbable monofilament surgical suture

A poly(L-lactide-co-caprolactone) copolymer, P(LL-co-CL), of composition 75:25 mol% was synthesized via the bulk ring-opening copolymerization of L-lactide and ε-caprolactone using a novel bis[tin(II) monooctoate] diethylene glycol coordination-insertion initiator, OctSn-OCH₂CH₂OCH₂CH₂O-SnOct. The P(LL-co-CL) copolymer obtained was characterized by a combination of analytical techniques, namely nuclear magnetic resonance spectroscopy, gel permeation chromatography, dilute-solution viscometry, differential scanning calorimetry, and thermogravimetric analysis. For processing into a monofilament fiber, the copolymer was melt spun with minimal draw to give a largely amorphous and unoriented as-spun fiber. The fiber's oriented semicrystalline morphology, necessary to give the required balance of mechanical properties, was then developed via a sequence of controlled offline hot-drawing and annealing steps. Depending on the final draw ratio, the fibers obtained had tensile strengths in the region of 200–400 MPa.     

Morphology and thermodynamic analysis of composite polymer particles prepared by soap‐free emulsion polymerization in the presence of poly(methyl methacrylate) and polystyrene as biseeds

Biseeds emulsion polymerization was investigated with poly(methyl methacrylate) (PMMA) and polystyrene (PSt) as biseeds and styrene (St) as second‐stage monomer, as well as with thermodynamic analysis; namely, the principle of minimum interfacial free‐energy change was utilized to explain the competitiveness of different seeds for second‐stage monomer and the final equilibrium morphology of composite polymer particles. The experimental results indicated the polymeric particles prepared had bimodal size distribution and the PMMA seed particles showed a higher chance of obtaining St than that of the PSt seed particles, which was in agreement with the computational outcome by the principle of minimum interfacial free‐energy change. Owing to the kinetic factors, the equilibrium morphology could not be reached in the experiments. However, the results demonstrated that double or multiple seeds emulsion polymerization could be used as a model experiment to study the morphology of polymer particle and the morphological prediction. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2675–2680, 2004