Study of oil soluble polymers as drag reducers

This investigation was undertaken to find the most effective material which would reduce the friction coefficient in turbulent flow when added in small quantities to oil pipelines. For this purpose, a series of oil-soluble polymers, namely homopolymers and copolymers of alkyl methacrylates, alkyl acrylates, and alkyl styrenes were synthesized. Emulsion polymerization techniques were used. Commercially available alkyl methacrylate and alkyl acrylate monomers were used in the synthesis. Monomeric alkyl styrenes were synthesized and structures established prior to polymerization. Intrinsic viscosities were measured and viscosity average molecular weights were calculated for several of the homopolymers synthesized in this study. Reduction of factional drag and resistance to shear degradation were measured by pumping a solution of the polymer in a hydrocarbon solvent through a pipe and recording the pressure drop across the pipe. Drag-reducing properties of several of the polymers were correlated in terms of their viscosity average molecular weights. Drag reduction of poly (isodecyl methacrylate) was studied in various hydrocarbon solvents. Drag-reducing behavior of polymers prepared in this study exhibited a strong dependence on molecular weight; increasing the molecular weight increased the drag reduction for a given polymer concentration and pipe size. Several of these polymers were found to be superior to commercially available polyisobutylene as drag reducers, especially in terms of shear stability.     

Higher‐molecular‐weight hyperbranched polyethylenes containing crosslinking structures as lubricant viscosity‐index improvers

As a new grade of polyethylene materials with unique chain architectures, hyperbranched polyethylenes synthesized by chain walking ethylene polymerization have great potential for industrial application as novel viscosity index (VI) improver in lubricant formulation. Although high‐molecular‐weight hyperbranched polyethylenes (weight‐average molecular weight of about 10⁵ g/mol) possess high shear stability, their viscosity thickening properties are compromised due to their compact chain architectures. In this work, we aim at improving their viscosity thickening property by increasing polymer molecular weight. A range of hyperbranched polymers of various enhanced molecular weights were synthesized by chain walking ethylene polymerization in the presence of small amounts of 1,4‐butanediol diacrylate as a difunctional crosslinker. The molecular weight dependences of viscosity thickening power and shear stability of these polymers containing crosslinking structures were evaluated. It is found that, with the increase of molecular weight via crosslinking, these polymers showed consistently enhanced viscosity thickening power, but with the reduced shear stability. However, their shear stability was still significantly better compared to linear polymers. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Synthesis of methacrylate copolymers and their effects as pour point depressants for lubricant oil

In this study, polymethacrylate polymers were synthesized by free‐radical polymerization for use as pour point depressants in lubricant oil, and their low‐temperature properties were investigated. Four methacrylate monomers were synthesized by the esterification of methyl methacrylate (MMA) with four kinds of fatty alcohols. The purification step was performed to prepare the pure monomers. Two polymerization experiments were carried out with four kinds of methacrylate monomers obtained previously and MMA. Copolymers, which were made from one kind of monomer and MMA, and terpolymers, which were made from two kinds of monomers and MMA, were prepared. The molecular structures of the synthesized methacrylate monomers and polymethacrylate polymers were verified by ¹H‐NMR, and the molecular weight data were obtained by gel permeation chromatography. The pour points of the base oils containing 0.1 wt % polymethacrylate polymers were measured according to ASTM D 97‐93. The pour points of most base oils containing each polymer decreased compared to that of the pure base oil. Particularly, poly(dodecyl methacrylate‐co‐hexadecyl methacrylate‐co‐methyl methacrylate), made of dodecyl methacrylate, hexadecyl methacrylate, and MMA at a molar ratio of 3.5 : 3.5 : 3, showed the best low‐temperature properties. This terpolymer dropped the pour point of the base oil by as much as 23°C, and its yield was 93.5%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and polymerization of a new iodine‐containing monomer

A new iodine‐containing methacrylate monomer, 3,4,5‐triiodobenzoyloxyethyl methacrylate (TIBEM), was synthesized by coupling 2‐hydroxyethyl methacrylate (HEMA) with 3,4,5‐triiodobenzoic acid. The monomer was characterized by ¹H nuclear magnetic resonance, infrared (IR), and ultraviolet spectra. Homopolymerization and copolymerization of the monomer with methyl methacrylate (MMA) were carried out using 2,2′‐azobis isobutyronitrile as the initiator. A terpolymer of TIBEM, MMA, and HEMA was also synthesized. The copolymers were characterized by IR, gel permeation chromatography, differential thermal analysis, and thermogravimetric analysis (TGA). High molecular weight polymers were produced with MMA at different feed compositions of TIBEM. The polymers were found to be freely soluble in common solvents for acrylic polymers. TGA showed little decomposition of the copolymer below 280°C. Copolymers showed good radiopacity at 25 wt % of TIBEM in the feed. These copolymers could find applications in medical and dental areas where radiopacity is a desirable feature of the implants. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2580–2584, 2003     

Synthesis of amphiphilic poly(methyl methacrylate)‐block‐poly(methacrylic acid) diblock copolymers by atom transfer radical polymerization

Atom transfer radical polymerization (ATRP) of 1‐(butoxy)ethyl methacrylate (BEMA) was carried out using CuBr/2,2′‐bipyridyl complex as catalyst and 2‐bromo‐2‐methyl‐propionic acid ester as initiator. The number average molecular weight of the obtained polymers increased with monomer conversion, and molecular weight distributions were unimodal throughout the reaction and shifted toward higher molecular weights. Using poly(methyl methacrylate) (PMMA) with a bromine atom at the chain end, which was prepared by ATRP, as the macro‐initiator, a diblock copolymer PMMA‐block‐poly [1‐(butoxy)ethyl methacrylate] (PMMA‐b‐PBEMA) has been synthesized by means of ATRP of BEMA. The amphiphilic diblock copolymer PMMA‐block‐poly(methacrylic acid) can be further obtained very easily by hydrolysis of PMMA‐b‐PBEMA under mild acidic conditions. The molecular weight and the structure of the above‐mentioned polymers were characterized with gel permeation chromatography, infrared spectroscopy and nuclear magnetic resonance. Copyright © 2005 Society of Chemical Industry     

Functional copolymers of p‐cumyl phenyl methacrylate and glycidyl methacrylate: Synthesis,characterization, and reactivity ratios

Free‐radical polymerization of p‐cumyl phenyl methacrylate (CPMA) was performed in benzene using bezoyl peroxide as an initiator at 80°C. The effect of time on the molecular weight was studied. Functional copolymers of CPMA and glycidyl methacrylate (GMA) with different feed ratios were synthesized by free‐radical polymerization in methyl ethyl ketone at 70°C, and they were characterized by FTIR and ¹H‐NMR spectroscopy. The molecular weights and polydispersity indexes of the polymers and copolymers were determined by gel permeation chromatography. The copolymer composition was determined by ¹H‐NMR. The glass‐transition temperature of the polymer and the copolymers was determined by differential scanning calorimetry. The reactivity ratios of the monomers were determined by the Fineman–Ross and Kelen–Tudos methods. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 336–347, 2005     

Synthesis,characterization, and reactivity ratios of copolymers derived from 4‐nitrophenyl acrylate and n‐butyl methacrylate

Free‐radical copolymerization of 4‐nitrophenyl acrylate (NPA) with n‐butyl methacrylate (BMA) was carried out using benzoyl peroxide as an initiator. Seven different mole ratios of NPA and BMA were chosen for this study. The copolymers were characterized by IR, ¹H‐NMR, and ¹³C‐NMR spectral studies. The molecular weights of the copolymers were determined by gel permeation chromatography and the weight‐average (M _w) and the number‐average (M _n) molecular weights of these systems lie in the range of 4.3–5.3 × 10⁴ and 2.6–3.0 × 10⁴, respectively. The reactivity ratios of the monomers in the copolymer were evaluated by Fineman–Ross, Kelen–Tudos, and extended Kelen–Tudos methods. The product of r₁, r₂ lies in the range of 0.734–0.800, which suggests a random arrangement of monomers in the copolymer chain. Thermal decomposition of the polymers occurred in two stages in the temperature range of 165–505°C and the glass transition temperature (T_g) of one of the systems was 97.2°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1817–1824, 2003     

Effect of initiators and ethoxylation degree of non‐ionic emulsifiers on vinyl acetate and butyl acrylate emulsion copolymerization in the loop reactor

Vinyl acetate and butyl acrylate copolymers were synthesized in the presence of ammonium persulfate and potassium persulfate initiators, mixture of non‐ionic and anionic emulsifiers, and polyvinyl alcohol as protective colloid in a loop reactor. The monomer ratio was chosen 85:15. The series of non‐ionic emulsifiers, which have 10–40 moles ethoxylated nonyl phenol, were combined with Nansa 66 (sodium dodecyl benzene sulfonate). The effects of the initiators on the physicochemical properties of copolymers were investigated by measuring conversion, viscosity, molecular weight, molecular weight distribution, and surface tension, respectively by using gravimetric method, Brookfield viscometer, gel permeation chromatograpy (GPC), and ring method. The effects of ethoxylation degrees of the non‐ionic emulsifiers to the same properties of copolymers were also investigated. It was determined that the copolymer viscosities showed different tendency for two initiators. They were increased by the increasing ethoxylation degree of the non‐ionic emulsifier for ammonium persulfate. In contrast, latex viscosity was decreased by increasing the ethoxylation degree in presence of potassium persulfate. Similar changes were also found in number average molecular weights of copolymers. On the other hand, weight average molecular weights of copolymers increased by increasing the ethoxylation degree of the non‐ionic emulsifier for both initiators. In the case of potassium persulfate, the surface tension values of copolymers increased by increasing the ethoxylation degree, but generally increasing the ethoxylation degree did not affect the surface tension of copolymer very seriously for two initiators. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 537–543, 2003     

Synthesis and characterization of the biomaterial poly(lactic acid‐co‐Nε‐carbobenzoyloxy‐L‐lysine) via direct melt copolymerization

With D,L ‐lactic acid and N^ϵ‐carbobenzoyloxy‐L ‐lysine [Lys(Z)] as the starting monomer material and tin dichloride as the catalyst, the drug carrier material poly(lactic acid‐co‐N^ϵ‐carbobenzoyloxy‐L ‐lysine) was synthesized via direct melt polycondensation. The copolymer was systematically characterized with intrinsic viscosity testing, Fourier transform infrared spectroscopy, ¹H‐NMR, gel permeation chromatography, differential scanning calorimetry, and X‐ray diffraction. The influences of different feed molar ratios were examined. With increasing molar feed content of Lys(Z), the intrinsic viscosity, weight‐average molecular weight, and polydispersity index (weight‐average molecular weight/number‐average molecular weight) gradually decreased. Because of the introduction of Lys(Z) with a big aromatic ring into the copolymer, the glass‐transition temperature gradually increased with increasing feed charge of Lys(Z), and all of the copolymers were amorphous. The copolymers, with weight‐average molecular weights from 10,500 to 6900 Da, were obtained and could reach the molecular weight level of poly(lactic acid) modified by Lys(Z) via the ring‐opening polymerization of the cyclic intermediates, such as lactide and morpholine‐2,5‐dione. However, a few terminal carboxyl groups might have been deprotected during the polymerization reaction under high temperatures. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of a chiral copoly(ether sulfone) with high molecular weight

A series of chiral poly(ether sulfone)s containing (S)‐binaphthyl unit were synthesized via nucleophilic substitution polycondensation. The as‐synthesized polymers were characterized by NMR. The molecular weights of these polymers were calculated by viscosity and gel permeation chromatography. The thermal stability was measured by TGA. The optical activities of the polymers were studied by circular dichroism and optical rotation. It was found that introducing more reactive 2,2′‐biphenol monomer to partly substitute the binaphthol monomer could increase the molecular weight of the polymer from 4.1 × 10⁴ to 9.8 × 10⁴ g mol^?1. Meanwhile, the thermal stability increased and the decomposition temperature rose from 447 to 518 °C, with the optical activity of the polymer well preserved. However, the value of the specific optical rotation decreased with increasing biphenol to binaphthol molar ratio. In addition, the optical rotation direction of the polymer was contrary to that of the pristine binaphthol monomer, which indicated that the chiral polymers formed a secondary structure. © 2013 Society of Chemical Industry     

SYNTHESIS,CHARACTERIZATION, AND THERMAL STABILITY OF HOMOPOLYMER AND COPOLYMER OF SOME 3-ARYL-2-HYDROXYPROPYL METHACRYLATES

Three new hydroxypropyl methacrylates having three different aryl rings were synthesized by addition of 2,3-epoxypropyl aromatic hydrocarbon to methacrylic acid. The monomers prepared are 3-phenyl-2-hydroxypropyl methacrylate, 3-tolyl-2-hydroxypropyl methacrylate, (THPMA), and 3-naphtyl-2-hydroxypropyl methacrylate. The homopolymers of these monomers and two different copolymers, [poly(THPMA-co-BMA)], were obtained from polymerization at 60°C in 1,4-dioxane solution using AIBN as initiator. All the monomers and the polymers were characterized by FT-IR and ¹H and ¹³C NMR techniques. Solubility parameters of the polymers and average molecular weight of poly(THPMA) were determined. Thermal stabilities of the polymers were given as comparing with each other by using TGA curves. Thermal degradation of poly(THPMA60%-co-BMA40%) was studied in detail.     

Synthesis,characterization, and thermal behavior study of methyl methacrylate polymers containing 4‐carbazole substitutes

A new polymerizable monomer, [4‐(9‐ethyl)carbazolyl]methyl methacrylate ( 2 ), was synthesized by reacting of methacrylic acid and 4‐hydroxymethyl‐9‐ethyl carbazole ( 1 ) by esterification procedure in the presence of N,N′‐dicyclohexylcarbodiimide. The resulting monomer was then polymerized free‐radically to form the poly(methyl methacrylate) containing 4‐(9‐ethyl)carbazolyl pend ent groups. Also, copolymerization of monomer 2 with various acrylic monomers such as methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, and n‐butyl acrylate by azobisisobutyronitrile as a free radical polymerization initiator gave the related copolymers in high yields. The structure of all the resulted compounds was characterized and confirmed by FTIR and ¹H NMR spectroscopic techniques. The average molecular weight of the obtained polymers was determined by gel permeation chromatography using tetrahydrofurane as the solvent. The thermal gravimetric analysis and differential scanning calorimeter instruments were used for studying of thermal properties of polymers. It was found that, with the incorporation of bulky 4‐(9‐ethyl)carbazolyl substitutes in side chains of methyl methacrylate polymers, thermal stability and glass transition temperature of polymers are increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4989–4995, 2006     

Synthesis and characterization of poly(dimethylamino ethyl methacrylate)–poly(ethylene oxide)–poly(dimethylamino ethyl methacrylate) triblock copolymers

Novel, monodispersed, and well‐defined ABA triblock copolymers [poly(dimethylamino ethyl methacrylate)–poly(ethylene oxide)–poly(dimethylamino ethyl methacrylate)] were synthesized by oxyanionic polymerization with potassium tert‐butanoxide as the initiator. Gel permeation chromatography and ¹H‐NMR analysis showed that the obtained products were the desired copolymers with molecular weights close to calculated values. Because the poly(dimethylamino ethyl methacrylate) block was pH‐ and temperature‐sensitive, the aqueous solution behavior of the polymers was investigated with ¹H‐NMR and dynamic light scattering techniques at different pH values and at different temperatures. The micelle morphology was determined with transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of novel rod–coil diblock copolymers of poly(methyl methacrylate) and liquid crystalline segments of poly(2,5‐bis[(4‐methoxyphenyl)oxycarbonyl] styrene)

Liquid crystalline diblock copolymers with different molecular weights and low polydispersities were synthesized by atom transfer radical polymerization of methyl methacrylate (MMA) and 2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene (MPCS) monomers. The block architecture (coil‐conformation of MMA segment and rigid‐rod of MPCS segment) of the copolymer was experimentally confirmed by a combination of ¹H nuclear magnetic resonance and gel permeation chromatograph techniques. The liquid crystalline behaviour of the copolymer was studied using differential scanning calorimetry and polarized optical microscope. It was found that the liquid crystalline behaviour was dependent on the number average molecular weight of the rigid segment. Only those copolymers with M_n(GPC) of the rigid block above 9200 g mol^?1 could form liquid crystalline phases higher than the glass transition temperature of the rigid block. The random copolymers MPCS‐co‐MMA were also synthesized by conventional free radical polymerization. The molar content of MPCS in MPCS‐co‐MMA had to be higher than 71% to maintain liquid crystalline behaviour. © 2003 Society of Chemical Industry     

Methacrylate‐based nanoparticles produced by microemulsion polymerization

Nanoparticles of methacrylate comonomers were obtained by microemulsion polymerization by using cetyltrimethylammonium bromide as the stabilizer. Stable and bluish transparent latexes were produced from these polymerizations in which potassium persulphate was used as the initiator. The viscosity average molecular weights were in between 6 × 10⁵ and 1.25 × 10⁶. The average diameters of the latex particles were in the range of 20–40 nm, which was obtained by scanning tunneling microscopy. The average particle diameter increased both with an increase in the relative amount of the comonomers and their type. The glass transition temperatures of these polymers obtained by DSC were in the range of 30–103°C, and decreased with the increase in the comonomer ratio. The comonomer ratios in the final copolymers were obtained from ¹H‐NMR spectra, which were smaller than those ratios used in the original recipes. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 569–575, 2000     

Atom transfer radical polymerizations of methyl methacrylate and styrene with an iniferter reagent as the initiator

Three novel iniferter reagents were synthesized and used as initiators for the polymerizations of methyl methacrylate (MMA) and styrene (St) in the presence of copper(I) bromide and N,N,N′,N″,N″‐pentamethyldiethylenetriamine at 90 and 115°C, respectively. All the polymerizations were well controlled, with a linear increase in the number‐average molecular weights during increased monomer conversions and relatively narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight ≤ 1.36) throughout the polymerization processes. The polymerization rate of MMA was faster in bulk than that in solution and was influenced by the different polarities of the solvents. A slight change in the chemical structures of the initiators had no obvious effect on the polymerization rates of MMA and St. The initiator efficiency toward MMA was lower than that toward St. The results of ¹H‐NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrum analysis, and chain‐extension experiments demonstrated that well‐defined poly(methyl methacrylate) and polystyrene bearing photolabile groups could be obtained via atom transfer radical polymerization (ATRP) with three iniferter reagents as initiators. The polymerization mechanism for this novel initiation system was a common ATRP process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Reverse iodine transfer polymerization of vinyl acetate and vinyl benzoate: synthesis and characterization of homo‐ and copolymers

Homo‐ and copolymers of vinyl esters including vinyl acetate (VAc) and vinyl benzoate (VBz) were synthesized via the reverse iodine transfer radical polymerization technique. Polymerization was carried out in the presence of iodine as the in situ generator of the transfer agent and 2,2′‐azobis(isobutyronitrile) as the initiator at 70 °C. Reverse iodine transfer radical homopolymerization of VAc and VBz led to conversions of 76 and 57%, number‐average molecular weights of 8266 and 9814 g mol^?1 and molecular weight distributions of 1.58 and 1.49, respectively. The microstructure of the synthesized polymers was investigated in detail using gel permeation chromatography, ¹H NMR, ¹³C NMR and distortionless enhancement of polarization transfer (135° decoupler pulse) techniques. Relatively narrow molecular weight distribution and controlled and predictable trend of molecular weight versus conversion were observed for the synthesized polymers, showing that reverse iodine transfer radical homo‐ and copolymerization of VAc and VBz proceeded with controlled characteristics. Results of molecular weight and its distribution along with the ¹H NMR spectra recorded for homo‐ and copolymers indicated that side reactions can occur during the course of polymerization with a significant contribution when VAc, even in a small amount, was present in the reaction mixture. This can result in polymer chains with aldehyde dead end and broadening of the molecular weight distribution. © 2015 Society of Chemical Industry     

Spectrofluorometric analysis and electrical conductivities of styrene and methylmethacrylate polymers by adding symmetrical polymethine dyes

To see the effect of conjugation on molecular weight and conductivity, three symmetrical polymethine dyes are added in polymers either before or after polymerization. Dyes have conjugated bonds between nitrogen atoms. Among three dyes, it was observed that as conjugation increases, the conductivity also increases. Previous study with polyethylvinylketone and polymethylvinylketone support the idea that increased conjugation will increase the molecular weight and conductivity. For these polymers also, the dopant, phosphorylchloride increased the conductivities due to the double bond being transferred to the main chain and increased conjugation. The same method developed in this work can be applied to methyl methacrylate and styrene polymers to see the relationship between molecular weight, conductivity, and fluorescence intensity. When dyes were added to methylmethacrylate and styrene monomers before polymerization, much higher conductivities were obtained. Conductivity values are directly proportional to the irradiation times and molecular weights. Four‐hour irradiation time results in a maximum molecular weight of 6.4 × 10⁵ and a maximum conductivity of 2.25 μS for MMA polymers. Spectrofluorometric analysis of methyl methacrylate polymers indicates that as molecular weight of the dyes increases, the emission intensities at 375 and 425 nm also increases. In the same way, increased molecular weight of polymer also results higher emission intensities. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Mechanisms of orientational and photoelastic birefringence generation of methacrylates for the design of zero–zero‐birefringence polymers

The intrinsic birefringence Δn⁰ and photoelastic coefficient C of poly(methyl methacrylate), poly(2,2,2‐trifluroethyl methacrylate), poly(phenyl methacrylate), and poly(2,2,3,3,3‐pentafluorophenyl methacrylate) were determined. We categorized these methacrylate polymers into four birefringence‐types, even though their molecular structures differed only by the substituents on the side chains. Based on the results of Δn⁰ and C, novel polymers that exhibit neither orientational nor photoelastic birefringence, i.e., zero–zero‐birefringence polymers, were designed and synthesized by quaternary copolymerization system. Furthermore, we confirmed that the mechanisms of orientational birefringence and photoelastic birefringence generation were different in these methacrylate polymers. The conformation of the repeat unit of the polymers was nearly constant during the generation of orientational birefringence. In contrast, the conformation of the repeat unit of the polymers changed during the generation of photoelastic birefringence in the glassy state. These findings demonstrated the reasonability of evaluating orientational and photoelastic birefringence separately, as well as the adequacy of the classification of polymers into four birefringence‐types. Given these results and the fact that zero–zero‐birefringence polymers could be prepared successfully by four‐birefringence type monomers, we demonstrated the reasonability of the method for designing the zero–zero‐birefringence polymers. POLYM. ENG. SCI., 55:1330–1338, 2015. © 2015 Society of Plastics Engineers     

Microbial screening of copolymers of 2,4‐dichlorophenyl methacrylate with N‐vinylpyrrolidone: synthesis and characterization

Copolymers of 2,4‐dichlorophenyl methacrylate and hydrophilic monomer (N‐vinylpyrrolidone) were synthesized with different feed ratios using dimethylformamide as solvent and 2,2′‐azobisisobutyronitrile as initiator at 70 °C. The copolymers were characterized by IR spectrometry. Copolymer compositions were determined by UV spectrometry. The monomer reactivity ratios were determined by applying the conventional linearization method of Fineman‐Ross. Gel permeation chromatography was employed for determining molecular weights and polydispersity indexes. Thermogravimetric analyses of polymers were carried out in nitrogen atmosphere. Homo‐ and copolymers were tested for their antimicrobial properties against selected microorganisms. © 2003 Society of Chemical Industry