Water-soluble copolymers: 21. Copolymers of acrylamide with 2-acrylamido-2-methylpropanedimethylammonium chloride: Synthesis and characterization

The copolymerization of acrylamide (AM) with 2-acrylamido-2-methylpropanedimethylammonium chloride (AMPDAC) has been studied in the range from 40 to 90% AM in the feed. The value of r₁r₂ has been determined to be 0.19 for the AM-AMPDAC pair. The copolymer compositions have been determined from elemental analysis and ¹³C n.m.r. The molecular weights of the copolymers were measured by low-angle laser light scattering, and ranged from 1.7–3.6 × 10⁶. Furthermore, the molecular weights were found to be relatively unaffected by monomer feed ratios. The copolymer microstructures, including run numbers and sequence distributions, were calculated from the reactivity ratios. These model structures are utilized for assessment of structure/dilute solution property relationships reported in a subsequent paper in this series.     

New amphoteric graft copolymers of sodium carboxymethyl cellulose with acrylamide and dimethylaminoethyl methacrylate: Aqueous solution properties

The solubility and viscosity properties of new amphoteric graft copolymers of sodium carboxymethyl cellulose with acrylamide and dimethylaminoethyl methacrylate in aqueous solutions were investigated by turbidimetry and viscometry experiments. The factors investigated include the pH of the medium, the composition of the graft copolymer, the concentration and type of added salt, temperature, aging time, and the addition of organic solvent. Unlike conventional copolymers, these graft copolymers have unique solution behavior due to the presence of both acidic and basic groups along the macromolecular backbone. In addition, their solution properties are closely related to their conformations and are partially controlled by the net electrical charge and the ionic strength. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 305–310, 2000     

Copolymers of N‐alkyl‐ and N‐arylalkylacrylamides with acrylamide: influence of hydrophobic structure on associative properties. Part II: rheological behaviour in semi‐dilute solution

BACKGROUND: Hydrophobically associating water‐soluble polymers are of great interest because they possess unique rheological behaviour that results from the reversible association/dissociation process of their hydrophobic moieties. In this study, we focused on the structure of hydrophobic monomers related to the rheological and viscoelastic behaviours in semi‐dilute solutions of acrylamide polymers modified with small amounts of N‐alkyl‐ and N‐arylalkylacrylamides (0.5 and 1 mol%). RESULTS: Associative efficiency increases with the length of the graft alkyl chain, with its proportion in the copolymer and with the presence of an aromatic group at the end of the alkyl graft chain. Introduction of hydrophobic groups induces a slowing down of the dynamics of the system, particularly marked for copolymers containing phenyldecyl chains. CONCLUSION: At low frequencies, solutions behave as Newtonian liquids; at higher frequencies, solutions of strongly associative systems behave as a solid with a storage modulus higher than the loss modulus and little dependency on the frequency. The system is a transient network whose dynamics depend on entanglements and hydrophobic associations. The presence of the hydrophobic groups induces an increase of the final relaxation time, even more pronounced since these associations are strong. Copyright © 2008 Society of Chemical Industry     

Water-soluble acrylamide copolymers: V. Dispersion properties of poly(acrylamide-co-p-maleimidobenzoic acid) and poly(acrylamide-co-sodium N,N-diallylsulfanilate)

Eight new poly(acrylamide-co-p-maleimidobenzoic acid) (PAMMBA) water-soluble copolymers, 3 , have been prepared in a synthetic study with the objective to determine the influence of ring incorporation on the surface activity of these materials.¹ Sufficient sample was obtained from three of these experiments to enable measurement of the dispersion properties of these polymers using aqueous kaolinite suspensions. PAMMBA-1, -2, and -3 copolymers containing 7, 13, and 23 mole percent p-maleimidobenzoic acid (MBA) were tested. Their effectiveness as dispersants increased with increasing MBA content. But the copolymer containing 23% MBA required a dose rate four to eight times that of DISPEX N-40, a commercial dispersant, to obtain equivalent dispersion properties from a standard kaolinite suspension. In similar copolymer synthesis experiments, ten new poly(acrylamide-co-sodium N,N-diallylsulfanilate) (PAMDAS) copolymers were also prepared and fully characterized.² Sufficient material was isolated from three of these preparations to enable testing of the dispersant activity. PAMDAS-1, -2, -3 copolymers contained 3·0, 8·4, and 19·2 mole percent sodium N,N-diallysulfanilate (DAS) and were tested as dispersants in experiments conducted so as to produce results comparable to those of both the PAMMBA copolymers and a commercial dispersant. Dispersant effectiveness increased with increasing DAS content. PAMDAS-1 (3·0% DAS) was about the same effectiveness as PAMMBA-1 (7% MBA), PAMDAS-2 (8·4% DAS) was more effective than PAMMBA-2 (13% MBA), and PAMDAS-3 (19·2% DAS) was about equivalent in effectiveness to PAMBA-3 (23% MBA). Relative to DISPEX N-40, however, PAMDAS-2, at a dose rate of 2000 ppm by weight was about half as effective as DISPEX N-40 at a 250 ppm dose rate.     

Copolymers of N‐alkyl‐ and N‐arylalkylacrylamides with acrylamide: influence of hydrophobic structure on associative properties. Part I: viscometric behaviour in dilute solution and drag reduction performance

BACKGROUND: Drag reduction properties from dilute aqueous polymer solution are obtained with very high molecular weight water‐soluble polymers. The aim of this work was to examine the potential of acrylamide polymers modified with small amounts of N‐alkyl‐ and N‐arylalkylacrylamides (0.5 and 1 mol%). RESULTS: The associative properties improve with the length of the graft alkyl chain, and with its proportion in the copolymer and with the presence of aromatic groups. The drag reduction efficiency of these copolymers in very dilute solution was measured to relate the activity to the molecular parameters. CONCLUSION: The results obtained indicate that the persistent drag reduction activity can be linked to the presence of strong intramolecular associations. Copyright © 2008 Society of Chemical Industry     

Copolymerization of hydroxyalkyl methacrylates with acrylamide and methacrylamide. II. Properties of the copolymers

Copolymers of 2-hydroxyethyl–methacrylate, 2-hydroxypropyl–methacrylate, or 3-chloro-2-hydroxypropyl methacrylate with acrylamide or methacrylamide having different compositions were synthesized by free radical bulk polymerization. Some of their properties, for example, density, polymerization shrinkage, Vicat's softening point, glass transition temperature, hardness, and thermal and chemical stability were measured. The effect of the content of acrylamide or methacrylamide units on the properties of copolymers is discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1243–1248, 1998     

水溶性微交联丙烯酰胺共聚物的表征与溶液性能

以丙烯酰胺(AM)为主要单体,以2-甲基-2-丙烯酰胺基丙磺酸(AMPS)为增溶单体,以二乙烯基苯(DVB)为交联单体,采用自由基胶束聚合法合成了水溶性微交联共聚物(PADM),研究了AMPS和DVB的反应加量、NaC l浓度、温度及剪切速率对共聚物溶液性能的影响。结果表明,引入DVB使共聚物具有优良的增粘和抗盐能力,DVB摩尔分率为0.7%的0.15 g/dL PADM于45℃在淡水和7.5 g/dL盐水中的表观粘度分别为376.9 mPa.s和155.4 mPa.s。另外,PADM也显示了良好的抗剪切和耐温性能。     

Synthesis of amphiphilic graft copolymers of SBS with acrylamide and study of their properties

Graft copolymerization of SBS in the form of sodium ionomer with acrylamide in emulsion using benzoyl peroxide as initiator and sodium ionomer of maleated SBS as a self‐emulsifier, which can form a stable cyclohexane/water emulsion with AM without using any other emulsifier, was carried out. Factors affecting the graft copolymerization were studied. The grafting % can reach about 15%. Emulsifying properties of sodium ionomer of maleated SBS and the graft copolymer, as well as the compatibilizing effect of the graft copolymer in blending polyvinyl chloride (PVC) with SBS, were studied. The sodium ionomer of maleated SBS, the graft copolymers, and the blends were characterized with IR and DSC. The results showed that water absorbency and emulsifying volume increase obviously after graft copolymerization with AM. 0.2 g of the graft copolymer containing 14 wt % PAM grafts can emulsify a mixture of 30 mL toluene and 70 mL water completely. The graft copolymer can be used as an effective compatibilizer in the blending of PVC and SBS, more effective than the sodium ionomer of maleated SBS. Only 2 wt % of the copolymer based on the blend used in blending is enough to raise the tensile strength three times. The blends with weigh ratios of PVC/SBS at 3/7–4/6 in the presence of the graft copolymer behave as thermoplastic elastomers with a tensile strength of 14 MPa, an ultimate elongation of 750%, and a permanent set of 17%. Glass transition temperatures of the blend shifted inward in the presence of the graft copolymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1248–1253, 2005     

丙烯酰胺/甲基丙烯酰氧乙基三甲基氯化铵/二甲基二烯丙基氯化铵三元聚合物的表征与溶液性质

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、二甲基二烯丙基氯化铵(DMDAAC)为单体原料,采用水溶液聚合技术制备了粉末型阳离子三元聚合物P(AM/DMC/DMDAAC)。采用红外光谱、核磁共振和热重分析对所制备阳离子聚合物进行了结构和组成表征,并利用电导率仪和布氏黏度计对其溶解性及其溶液黏度进行了测定。结果表明:合成的产物为P(AM/DMC/DMDAAC),具有良好的热稳定性和溶解性。三元聚合物的表观黏度随着聚合物质量浓度的增加先减小后增加,随剪切速率的增加而下降。在不同的外加盐溶液里,三元聚合物溶液表现出明显的反聚电解质行为。     

Water-soluble copolymers,XXIV. Copolymers of acrylamide with N-(1,1-dimethyl-3-oxobutyl)-N-(n-propyl)acrylamide: Solution properties

Solution properties of copolymers of acrylamide (AM) with N-(1,1-dimethyl-3-oxobutyl)-N-(n-propyl)acrylamide (PDAAM) of known molecular weight have been studied as a function of composition, added electrolytes, and polymer concentration. Arrhenius-type studies have been performed by viscometry and NMR to assess the effects of temperature. Phase separation studies have also been performed using turbidimetry. The solution properties of the AM-PDAAM copolymers are dictated by the presence of intramolecular hydrophobic interactions. These interactions may result in decreased hydrodynamic dimensions relative to polyacrylamide of similar molecular weight.     

Water-soluble copolymers. VI. Dilute solution viscosity studies of random copolymers of acrylamide with sulfonated comonomers

Dilute solution viscosity of a series of random copolymers of acrylamide (AM) with sodium-2-acrylamido-2-methylpropane sulfonate (NaAMPS) and with sodium-2-sulfoethylmethacrylate (NaSEM) has been studied using a four-bulb shear dilution capillary viscometer. The hydrodynamic volume of the copolymers in aqueous media was determined as a function of salt concentration, temperature, shear rate, and time. A linear relationship was observed between the intrinsic viscosity [η]₀ and the reciprocal of the square root of ionic strength in sodium chloride solutions, with salt concentrations varying from 0.043M to 0.257M. Negative temperature coefficients for [η]₀ indicate a decrease in the hydrodynamic volume of the ionic polymer molecules with increasing temperature. The relative zero-shear-intrinsic-viscosity change in distilled water to 0.257M sodium chloride aqueous media is used to elucidate viscosity–structure relationships. A maximum value is reached for this parameter at a composition of about 30 mol % of ionic comonomers for AM–NaAMPS and AM–NaSEM copolymer series.     

丙烯腈-丙烯酰胺共聚物的合成与热性能研究

采用溶液自由基法制备了丙烯腈(AN)-丙烯酰胺(AM)共聚物,采用傅立叶变换红外光谱(FTIR)、核磁共振光谱(NMR)、差示扫描量热仪(BSC)和热重分析(TG)等方法对聚合产物进行了表征。研究结果表明,随着AM的加入,共聚物的分子质量和转化率都具有先增大后减小的变化趋势。AN的质量分数为2%(w)时,分子质量和转化率最高,且共聚单体AM能在较低温度时以离子机理形式引发聚丙烯腈(PAN)原丝的氧化、环化放热反应并能减缓放热效应。     

Solution and interfacial behavior of hydrophobically modified water-soluble block copolymers of acrylamide and N-phenethylacrylamide

Hydrophobically modified water-soluble block copolymers were prepared by aqueous micellar copolymerization of acrylamide and small amounts (2 and 3 mol %) of a hydrophobe (N-phenethylacrylamide) that is characterized by a long spacer that places the aromatic ring far away from the backbone, with the objective of investigating the copolymers' rheological behavior and surface and interfacial activities under various conditions such as polymer concentration, shear rate, temperature, and salinity. As expected, the block copolymers exhibit improved thickening properties attributed to intermolecular hydrophobic associations as the solution viscosity of the copolymers increases sharply with increasing polymer concentration. Additional evidence for intermolecular association is provided by the effect of NaCl, the presence of which substantially enhances the viscosity. An almost shear rate–independent viscosity (Newtonian plateau) is also exhibited at high shear rate and a typical non-Newtonian shear thinning behavior appears at low shear rates and high temperatures. Furthermore, the block copolymers exhibit high air–liquid surface and liquid–liquid interfacial activities as the surface and interfacial tensions decrease with increasing polymer concentration, indicating strong adsorption of the copolymer at the interface. The surface and interfacial tensions exhibited by the copolymers were found to be relatively insensitive to the concentration of salt (NaCl). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 467–476, 2001     

Segmented organosiloxane copolymers: 2 Thermal and mechanical properties of siloxane—urea copolymers

The structure-property behaviour of new siloxane-urea containing segmented copolymers has been investigated. Amino-propyl terminated poly(dimethylsiloxane) oligomers of from 900–3660 M_n were reacted with various diisocynates to form segmented copolymers with urea linkages. The length of the hard segments in these copolymers corresponds approximately to the length of the diisocynate unit employed. A number of mechanical and thermal properties were investigated for these phase separated materials. It was found that the performance of these copolymers was effected by varying the hard segment type and/or content and that high strength necessitates a microphase texture. The two phase nature of these copolymers was verified by dynamic mechanical, thermal and SAXS studies. The phase separation was found to occur in these copolymers even with 6% hard segment by weight. In conclusion, these materials displayed a behaviour similar to the segmented polyurethanes and were found to be superior to the unfilled silicone elastomers.     

Water-soluble copolymers,XXIII. Copolymers of acrylamide with N-(1,1-dimethyl-3-oxobutyl)-N-(n-propyl)acrylamide: Synthesis and characterization

The copolymerization of acrylamide (AM) with N-(1,1-dimethyl-3-oxobutyl)-N-(n-propyl)acrylamide (PDAAM) has been studied in the range from 5 to 20% PDAAM in the feed. The copolymer compositions have been determined from elemental analysis and ¹³C-NMR. Reactivity ratio studies have been performed and the value of r₁ r₂ determined to be 2.20. The molecular weights of the copolymers were found to decrease with increasing PDAAM content in the feed. The copolymer microstructures were predicted from the experimentally determined reactivity ratios. These model structures are utilized for assessment of structure/dilute solution property relationships reported in a subsequent paper in this series.     

Synthesis and solution properties of an associative polymer with excellent salt-thickening

To enhance apparent viscosities in brine solutions with high salinities for associative water-soluble polymers, a novel macromonomer (APEO): allyl-capped octylphenoxy poly(ethylene oxide) (degree of polymerization: 14) was synthesized, and a novel tetra-polymer (PAVO) was synthesized by copolymerizing APEO, acrylamide (AM), sodium 2-acrylamido-2-methylpropane sulfonate (NaAMPS), and vinyl biphenyl (VP). The macromonomer and the PAVO polymer were characterized with Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (¹H-NMR). The apparent viscosities of PAVO in pure water were very low over all polymer concentrations, and the critical association concentration (C*_p) was 0.15 g dL⁻¹. However, in brine solutions above 40 g L⁻¹ NaCl or 10 g L⁻¹ CaCl₂, the intermolecular hydrophobic associations of octylphenyl groups and biphenyl groups were enhanced dramatically, the polymer chains were still comparatively extended due to the incorporation of APEO into the polymer, C*_p was reduced to 0.10 g dL⁻¹, and the apparent viscosities were significantly higher than in pure water. The PAVO brine solutions exhibited excellent salt-thickening induced by metallic univalent or bivalent cations, heat-thickening effect, shear-thickening behavior, and thixotropy. Moreover, the brine solution also performed good resistance to ageing because of the simultaneous incorporation of bulky side groups. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical properties of poly(vinyl chloride) blends and corresponding graft copolymers

The mechanical properties of the poly (vinyl chloride) (PVC) and poly (glycidyl methacrylate) [poly (GMA)] blend system and the PVC and poly (hydroxyethyl methacrylate) [poly (HEMA)] blend system and their crosslinked films were investigated. At the same time, the mechanical properties for the corresponding graft copolymers such as PVC-g-GMA, PVC-g-HEMA, and their crosslinked films were also investigated in this study. The results showed that the tensile strengths for PVC–poly (GMA) blend systems were higher than those for PVC-g-GMA graft copolymer, and the tensile strengths for PVC-g-HEMA were higher than those for PVC-poly (HEMA) blend systems. However, the mechanical properties for the PVC–poly (GMA) blend system were not affected by the crosslinking of the blend system, but those for PVC-poly (HEMA) and their graft copolymers decreased with an increase of the equivalent ratio ([NCO]/[OH]) of the crosslinker. Finally, the surface hydrophilicity of the PVC-g-HEMA graft copolymer and PVC-poly (HEMA) blends were also assessed through measuring the contact angle. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 307–319, 1998     

Lower critical solution temperature behavior of amphiphilic copolymers based on polyaspartamide derivatives

Novel copolymers consisting of poly(N‐isopropylaminoethyl‐co‐6‐hydroxyhexyl aspartamide) and poly (N‐isopropylaminoethyl‐co‐hexyl aspartamide) were prepared from polysuccinimide, which was the thermal polycondensation product of L ‐aspartic acid, via a ring‐opening reaction with 6‐amino‐L ‐hexanol (AH) or hexylamine (HA) and N‐isopropylethylenediamine at different ratios. The copolymers, containing 75–90 mol % of AH and 35–45 mol % of HA, produced thermoresponsive polymers through their lower critical solution temperatures (LCSTs) in aqueous solution. We could control the LCST could be controlled by modifying the hydrophobic–hydrophilic balance by changing the content of AH or HA. The pH dependencies of the LCST were opposite in these two different copolymer systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Copolymers of haemin and vinyl monomers as cyanide ion exchangers: Modifications of the ion exchange properties by introduction of acrylamide residues

Ternary copolymers of haemin (H) and styrene (St) with acrylamide (AAm), copoly(H, St, AAm), and with 1-vinyl-2-pyrrolidone (VP), copoly(H, St, VP), were synthesized by radical copolymerization. It was found that the H content of the resulting copolymer generally agrees with that of the corresponding monomer feed. Moreover, the yield and reduced viscosity decrease in proportion to the feed concentration of the H monomer. Each copolymer prepared showed hydrophilic character compared with the copolymer of H and St. The adsorption of cyanide ion onto the copolymer was investigated at different pHs to clarify the functional capability as cyanide ion exchanger. The amount of cyanide ion adsorbed on 1 g dry polymer (A_cn in mg/g) was found to be dependent on the H content of the copolymer, thus indicating that the haem-iron is the adsorption site of the cyanide ion. From the curves of A_cn against the AAm or VP content of the copolymer and against pH for copoly (H, St, AAm) and copoly(H, St, VP), it was observed that the adsorptive capacity of the cyanide ion is increased by the introduction of the AAm residue. The same result was obtained for column experiments. These results were discussed in connection with the reaction of a cyanide ligand with the haem-iron site in the copolymer.     

Aqueous dispersion polymerization of acrylamide with quaternary ammonium cationic comonomer

Using aqueous solution of ammonium sulfate as medium, acrylamide (AM) and dimethylaminoethyl methacrylate methyl chloride (DMC) as main raw materials, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as stabilizer and 2,2′‐azobis (2‐amidinopropane) dihydrochloride (V‐50) as initiator, the cationic polyelectrolyte of P(DMC‐AM) was synthesized by aqueous dispersion polymerization. The effects of the major reaction variables on synthesis conditions, product characteristics (particle size and molecular weight), and polymerization rate were investigated. The polymerization was retarded by the presence of the ammonium sulfate. The optimum reaction conditions for obtaining a stable aqueous dispersion were concentrations of 1.8 × 10^?4–7.0 × 10^?4 mol L^?1 for V‐50, 1.5–3.5% for stabilizer, and 23.2–30.0% for salt. The molecular weight of PDMC formed was 1.5 × 10⁵ to 7.0 × 10⁵. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008