Radiation induced terpolymerization of tetrafluoroethylene with propylene and n-butyl vinyl ether in bulk

Terpolymerization of tetrafluoroethylene (TFE) with propylene (P) and n-butyl vinyl ether (NBVE) induced by γ-rays at room temperature at dose rate 5 × 10⁵ rad/h and P/NBVE molar ratio from 49/1 to 10/40 was carried out. An alternating copolymerization between TFE and two α-olefins was found to take place in this system, so that 50 mole % of TFE containing terpolymer is always formed at various monomer compositions. The terpolymer composition can be explained successfully by the treatment by a complex mechanism. The complex reactivity ratios of r_I (TFE–complex) and r_II (TFE-NBVE complex) were calculated to be 0.5 and 0.6, respectively, assuming a complex mechanism. The polymerization rate and molecular weight increase with NBVE concentration in the monomer mixture. Colorless transparent rubber-like polymers were obtained at each monomer composition. The glass transition temperature sharply decreases with NBVE concentration in the terpolymer but the thermal and chemical resistances of the terpolymer slightly decrease. Considering these results together with the mechanical properties it has been concluded that the 45/48/7 terpolymer of TFE/P/NBVE molar ratio is good as a practical elastomer useful at relatively low temperatures.     

Effects of poly(N‐isopropylacrylamide) on the solution properties of hydrophobically modified acrylamide copolymer

The hydrophobic interaction between hydrophobically modified acrylamide copolymer (HMPAM) and poly(N‐isopropylacrylamide) (PNIPAM) in aqueous solutions was investigated. The results show that the solution properties of HMPAM are significantly influenced by the addition of PNIPAM. In dilute regime, the intrinsic viscosity of HMPAM in 0.025 wt % PNIPAM/0.1 M NaCl mixed solution is 17.52 dL g^?1, about 2 times 8.66 dL g^?1, that in 0.1 M NaCl solution, which is due to the attractive interaction between the hydrophobic parts of PNIPAM and HMPAM molecules. In semidilute regime, below the saturation concentration, the addition of PNIPAM can lead to both the apparent viscosity and the modulus of HMPAM solutions increasing, which is attributed to the number of aggregation junctions increasing, responsible for the increase of the contribution of the reversible network to the viscosity increase, the β value. In addition, a thermothickening behavior for the HMPAM/PNIPAM mixed solution is observed with increasing temperature over 15–30 °C, which is consistent with the large increase of the Huggins coefficient of HMPAM in the presence of PNIPAM from 1.95 to 7.59 as temperature increases from 25 to 30 °C. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 709–715, 2005     

The self‐assembly over nano‐ to submicro‐length scales in water of a fluorescent julolidine‐labeled amphiphilic random terpolymer

A novel fluorescent‐labeled amphiphilic random terpolymer is synthesized by controlled radical polymerization of a fluorescent molecular rotor monomer, 2‐cyano‐2‐[4‐vinyl(1,1′‐biphenyl)‐4′‐yl]vinyljulolidine, a hydrophilic monomer, poly (ethylene glycol) methyl ether methacrylate, and a hydrophobic monomer, perfluorohexylethyl acrylate. Combined dynamic light scattering and fluorescence emission spectroscopy measurements are used to investigate its self‐assembly in water solution. Self‐assembled nanostructures with a hydrodynamic diameter size D_h of 4 ± 1 nm are detected due to the single‐chain folding of the terpolymer in unimer micelles. The fluorescence emission intensity of the terpolymer in water solution is found to be one order of magnitude higher than that in organic solvents, as a result of the preferential encapsulation of the julolidine co‐units in hydrophobic compartments of the unimer micelles. The temperature dependence of the self‐associative behavior of the amphiphilic terpolymer is also investigated and a critical temperature is identified at which a transition between single‐chain unimer micelles and multi‐chain aggregates (D_h = 400 ± 40 nm) reversibly takes place on heating–cooling cycles. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 797–804     

Synthesis and properties of temperature-resistant and salt-tolerant tetra-acrylamide copolymer

Abstract

The acrylamide copolymer with acrylamide as its main monomer is a modified polyacrylamide. In addition, the acrylamide copolymer is generally to dissolve or swell in water and can be used as thickener, dispersant, flocculant and so on. Therefore, using Acrylamide AM, 2-acrylamide-2-methyl propanesulfonic acid AMPS, dimethyldodecyl (2-acrylamidoethyl) ammoniumbromide AQ₁₂ and vinyltriethoxysilane VTEO as raw materials so that a series of four-membered acrylamide copolymers are prepared in aqueous solution polymerization. The amphoteric structure in the polymer has a unique anti-polyelectrolyte behavior when it is electrically neutral, which can significantly improve the salt resistance of the aqueous polymer. In addition, the hydrolysis of the vinyltriethoxysilane containing silicon structure by hydrophobic association can improve the temperature resistance of the polymer. The optimal reaction conditions were determined by orthogonal experiment: the reaction temperature was 10?°C; the initiator concentration was 0.05?mol%; the monomer concentration was 25?wt% and the pH was 7. Properties of polymer solution indicated that the series of tetra-copolymer possessed salt-tolerant and heat-resisting performances. As an oil displacing agent, it can significantly improve the efficiency of oil displacement, and particularly highlights the effect of 4-member copolymer as an oil displacing agent.     

Graft copolymerization of methacrylic acid and acrylamide onto acrylonitrile-butadiene-styrene terpolymer by photoinduced hydroperoxide

Graft copolymerization of methacrylic acid (MAA) or acrylamide (AM) from an aqueous solution onto acrylonitrile-butadiene-styrene terpolymer (ABS) was initiated by the thermal decomposition of polymeric hydroperoxides, which are formed upon UV irradiationof ABS, which contains anthracene. Diffusion of anthracene at room temperature from a methanolic solution into ABS was affected by the acrylonitrile content ofABS.The graft yield was independent on the concentration of anthracene in the wide range of 0.03 X 10^-3 to 14.29 X 10^?3 mol/L in ABS. The graft polymerization reaction does not occur below 100°C.The effect of other variables, such as time of irradiation, intensity of UV, reaction time, and concentration of monomer in aqueous solution, on the amount of monomer grafted to ABS were also investigated.The contact angle significantly decreases upon grafting, indicating that the graft layer is on the surface of the polymer. © 1995 John Wiley & Sons, Inc.     

Terpolymerization of p-acetylpyridine oxime, p-methylacetophenone and formaldehyde, and its thermal studies

A terpolymer resin involving p-acetylpyridine oxime and p-methylacetophenone with formaldehyde (APOMAF) was synthesized by condensation polymerization in the presence of an acid catalyst. The structure of terpolymer was elucidated by FT-IR, ¹H NMR, pyrolysis gas chromatography mass spectrometer (Py?CGC?CMS), nitrogen adsorption/desorption analysis, Ubbelohde viscometer and non-aqueous conductometric titration, TG?CDTG and DSC. Molar fractions of monomer, condensing and comonomer unit (m ₁, m ₂, and m ₃) in APOMAF using ¹H NMR analysis data were calculated as 1.67; 0.27 and 0.66?mol%, respectively. The apparent activation energy of terpolymer by using various degradation models including the Flynn?CWall?COzawa (FWO), Kissinger?CAkahira?CSunose (KAS), and Friedman methods were 140.3; 144.9 and 129.9?kJ?mol^?1, respectively. The results from isoconversional degradation kinetics and Pyrolysis (GC?CMS) indicates that the degradation mechanism of terpolymer are likely limited by at least two-reaction step, the first being associated with the loss of the pendent methyl, acetyl, and oxime groups (side group elimination) while the second mass loss being due to the degradation of the terpolymer backbone (random scission) which clearly indicates that grafting pendant groups to the terpolymer backbone yields polymers with lower thermal stability. From the calculation, the solid state thermal degradation mechanism is proposed to be D₃ (three-dimensional diffusion) at initial stage and F ₁ (Random nucleation with one nucleus on the individual particles) at final stage.     

A Study of the Molecular Weight Distribution of Poly(Amino Acid)s Synthesized by Diphenyl Phosphoryl Azide

Abstract

Direct polycondensations of β-benzyl-l-aspartate (Asp.Bz) and β-benzyl-l-glutamate (Glu.Bz) were carried out in the presence of diphenyl phosphoryl azide (DPPA) as a condensation agent and triethyl amine (TEA). Poly(amino acid)s were obtained by this convenient approach whose structure was confirmed by IR and ¹H-NMR spectroscopy. The effects of the monomer concentration, the polymerization time and temperature, the ratios [DPPA]/[monomer] and [TEA]/[monomer], and the solvent used on the molecular weight distribution of the polymer were studied. When the monomer concentrations were higher than 0.2 g/mL, poly(Asp.Bz) with a bimodal molecular weight distribution was obtained (M_w of 37,000 and M_w/M_n of 1.68). The polycondensations carried out in THF or in bulk provided the highest molecular weight (M_w ? 40,000). Several other amino acids were also polymerized by DPPA.     

Superfast Responsive Ionic Hydrogels: Effect of the Monomer Concentration

A series of strong polyelectrolyte gels were prepared in aqueous solution, using the sodium salt of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) as the monomer and N,N'‐methylene(bis)acrylamide (BAAm) as a crosslinker. The gels were both prepared below (?22°C) and above (25°C) the bulk freezing temperature of the water, producing cryogels and hydrogels, respectively. The crosslinker (BAAm) content was set at 17 mol%, while the initial monomer concentration C_o was varied over a wide range. It was found that, at ?22°C, a macroscopic network starts to form at an initial monomer concentration of as low as 0.1 w/v%. In contrast to the conventional hydrogels formed at 25°C, the cryogels have a discontinuous morphology consisting of polyhedral pores of sizes 10⁰–10² μm. The cryogels exhibit superfast swelling properties, as well as reversible swelling–deswelling cycles in water and acetone. An increase in the initial monomer concentration from 2.5 to 10% further increases the response rate of the cryogels due to the simultaneous increase of the porosity of the networks.     

疏水改性聚丙烯酰胺的荧光研究

使用荧光探针技术,跟踪了疏水改性聚丙烯酰胺(HMPAM)在溶液中的变化过程,对HMPAM在溶液中的聚集行为进行了研究。同时也对部分水解聚丙烯酰胺(HPAM)作了对比研究。发现HMPAM在溶液中具有独特的变化规律:由疏水缔合形成超分子聚集体,再由超分子聚集体形成布满整个溶液空间网络结构的过程。并使用粘度法对其宏观流变性能进行了研究,发现两种手段所得的结果具有较好的对应关系。     

Graft Copolymerization of Methyl Methacrylate onto Nylon 6 Using Thallium(III) Ions as Initiator

Abstract

Graft copolymerization of methyl methacrylate onto nylon 6 was investigated in aqueous perchloric acid medium using thallium(III) ions as initiator. The rate of grafting was evaluated by varying the concentrations of monomer, initiator, acid, and temperature. The rate of grafting was found to increase with an increase of both monomer and initiator concentrations. The graft yield was found to increase with an increase in the acid concentration up to 0.49 mL^?1, and beyond this concentration of perchloric acid the graft yield was found to decrease. It also increased with an increase of temperature. From the Arrhenius plot the overall activation energy was found to be 3.9 kcal/mol. The effects of inhibitors, various solvents, inorganic salts, and swelling agents on graft yield were studied. A suitable kinetic scheme has been proposed and a rate equation has been derived.     

碳酸乙烯酯溶剂中丙烯腈的聚合行为

以碳酸乙烯酯为溶剂,偶氮二异丁腈（AIBN）为引发剂,采用溶液自由基聚合的方法对丙烯腈(AN)均聚合、丙烯腈/衣康酸(AN/IA)二元共聚及丙烯腈/衣康酸/丙烯酸甲酯(AN/IA/MA)三元共聚合进行了研究。 考察了反应温度对丙烯腈均聚合,以及聚合单体浓度对丙烯腈共聚合的影响,在60 ℃合成了相对分子质量高于4.5×105、单体转化率高于85%的丙烯腈均聚物及共聚物。 采用正十二烷基硫醇（DDT）和甲酰基哌啶（FP）作为链转移剂,对AN均聚物、AN/IA及AN/IA/MA共聚物的相对分子质量进行调控,考察了链转移剂浓度对聚合物相对分子质量和单体转化率的影响。 结果表明,w(DDT)为0.25%时（以单体质量计）,聚合物相对分子质量可有效调节到1×105,而单体转化率保持在80%以上。     

Poly(<Emphasis Type="Italic">n</Emphasis>-octyl methacrylate) viscosity index improver: Kinetic study via on-line <Superscript>1</Superscript>H-NMR technique

The free radical solution polymerization of n-octyl methacrylate has been studied in benzene-d ₆ in the presence of 2,2′-azobisisobutyronitrile as thermal initiator. An on-line nuclear magnetic resonance spectroscopy was applied to record the reaction data and to determine the monomer conversion at different times during the polymerization reaction. Effect of monomer and initiator concentration as well as reaction temperature on polymerization rate was studied. The order of the reaction with respect to initiator (0.45) was consistent with the classical kinetic rate equation, while the order of reaction with respect to monomer (1.87) was much greater than unity. An overall activation energy (E _a = 53.8 kJ/mol) was obtained over the temperature range 328?338 K. Also, the efficiency of the synthesized poly(n-octyl methacrylate) for improving the viscosity index of the lube oil was investigated.     

Liquid crystalline polymers XV. Synthesis,properties and cytotoxicity of photoresponsive thermotropic liquid crystalline copoly(arylidene-ether)s based on 4-tert-butylcyclohexanone and cyclohexanone moieties in the main chain

A new series of photoresponsive thermotropic liquid crystalline copoly(arylidene-ether)s based on both 4-tert-butylcyclohexanone and cyclohexanone moieties in the main chain were synthesised using solution polycondensation technique of both with different 4,4?-diformyl-α,ω-diphenoxyalkane derivatives. Two model compounds were synthesised from the reaction of each cycloalkanone monomer with benzaldehyde, and their structures were determined using single crystal X-ray diffraction. The structure of the monomers and copolymers was confirmed by elemental and spectral analyses. In addition, the thermal stabilities of these copolymers were evaluated by thermogravimetric analysis. We performed both differential scanning calorimertric and polarised optical microscopic measurements to investigate the thermotropic liquid crystalline properties of synthesised copolymers. The UV?Vis absorption spectroscopy of the liquid crystalline copoly(arylidene-ether) 6f revealed that the system undergoes Entgegen/Zusammen (E/Z) photoisomerisation using UV lamp (450 nm). Moreover, the various characteristics of the prepared copolymers including: solubility, X-ray diffraction analysis, gel permeation chromatography (GPC) and scanning electron microscopy were determined and discussed. The cytotoxicity of the model compounds and selected examples of these copolymers was tested against MCF-7 breast cancer cells. All tested samples showed considerable results, where 6c copolymer gave the best result; it showed cytotoxicity against MCF-7 cell line with IC₅₀ of 0.26 µM.     

Studies on Interaction of Hydrophobically Modified Polyacrylamide of a New Family with Cationic Gemini Surfactant

A new family of hydrophobically modified polyacrylamides (HMPAM) was synthesized via homogeneous copolymerization of acrylamide (AM) and anionic surface-active monomer of acrylamide-type, sodium 2-acrylamido-tetradecane sulfonate (NaAMC₁₄S) in aqueous solution. The copolymers NaAMC₁₄S/AM with microblock structures and with different chain microstructures were obtained by varying the copolymerization factors, such as the feed ratio of NaAMC₁₄S to AM and the amount of added electrolyte NaCl and initiator. The interaction between copolymers NaAMC₁₄S/AM and cationic gemini surfactants, C₁₂C₃C₁₂Br₂ and C₁₂C₆C₁₂Br₂, was studied by using viscosimetry and fluorescent probe technique. The results show this new family of HMPAM, NaAMC₁₄S/AM, has very strong interaction with gemini surfactants, and their aqueous solutions exhibit unique rheological properties.     

Radiation-induced terpolymerization of tetrafluoroethylene with propylene and isobutylene in bulk

Terpolymerization of tetrafluoroethylene (TFE) with propylene (P) and isobutylene (iB) by γ radiation at temperatures of ?78 to 40°C, a dose rate of 5 × 10⁴?5 × 10⁵ rad/hr, and an iB/P molar ratio of 40/10?5/45 in the monomer mixture was carried out. Alternating copolymers of TFE and α-olefins, that is, P and iB, were formed at various monomer compositions. No crystalline structure was observed in the terpolymer obtained below an iB/P molar ratio of 15/35 in the monomer mixture but a partly crystalline order increased with the amounts of iB in terpolymer. The crystal lattice of the TFE–iB copolymer was affected by the introduction of P. The dose rate dependencies of the polymerization rate and inherent viscosity were 0.8 and ?0.2, respectively. The activation energy of polymerization was 2.4 kcal/mole, and the relative reactivity ratio of iB and P for a TFE radical chain end was estimated as 4.50 by the treatment of the free propagating mechanism.     

Ethylene–propylene copolymerization behavior of ansa‐dimethylsilylene(fluorenyl)(amido)dimethyltitanium complex: Application to ethylene–propylene–diene or ethylene–propylene–norbornene terpolymers

Copolymerization behavior of ethylene (E) and propylene (P) using ansa‐dimethylsilylene(fluorenyl)(amido)dimethyltitanium complex was investigated. P was more reactive than E regardless of the chain‐end monomer unit, which was very unusual in the coordination polymerization system. The terpolymerizations of E, P and norbornene (NB) or 5‐ethylidene‐2‐norbornene (5E2N) were also performed. The each content in the E/P/NB terpolymer was independently controlled by the initial concentration of NB and E/P feed ratio. Glass transition temperature (T_g) of the terpolymer was raised in proportion to the NB content and close to that of the corresponding NB/E random copolymer with the same NB content. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 685–691     

Terpolymerization of Butadiene,Acrylonitrile, and Methacrylic Acid

Abstract

The terpolymerization of butadiene, acrylonitrile, and methacrylic acid in emulsion, using potassium persulfate as initiator and sodium dioctylsulphosuccinate as emulsifier, was investigated. For the binary system butadiene (M₁) and methacrylic acid (M₂), the following monomer reactivity ratios were determined: r₁₂ = 0.18 ± 0.05 and r₂₁ = 0.52 ± 0.09. When polymerizations were stopped at low conversions they gave terpolymers which show good agreement between experimental and theoretical copolymerization composition data, calculated from the Alfrey-Goldfinger equation. The relationships between monomer feed and terpolymer compositions are presented on triangular coordinate graphs as proposed by Slocombe. By using a computer program, the lines of unique composition and the lines of binary azeotropic composition were established. No point of true azeotropic composition was found, but a “pseudo-azeotropic” region was recognized. The influence of composition on glass transition temperature and thermal characteristics of the terpolymers is described.     

离子液体中AM/AMPS/N8AM三元共聚物的合成及溶液性能

以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为亲水单体, 以N-辛基丙烯酰胺(N8AM)为疏水单体, 在离子液体[bmim]BF4中实现了疏水缔合丙烯酰胺三元共聚物的合成.     

Triad Concentrations (P 12 P 23 P 31 and P 13 P 32 P 21) as a Guide to Monomer Reactivity in Copolymers and Terpolymers

Abstract

A simple procedure using triangular coordinates for representing triad concentrations as a function of terpolymer compositions (and monomer proportions) is presented. Equal triad concentrations are represented by concentric closed loops or rings of equal triad concentrations converging to a unique point of highest triad concentration. The technique is illustrated with several common terpolymer systems. Alternation in terpolymer systems is assessed by determination of heterotriad concentrations. These results are compared with alternation in component binary systems. An equation is derived for calculating P ₁₂ P ^MAX ₂₁, maximum 1,2-dyad concentration (maximum mol fraction alternation) from r ₁ r ₂ product at equimolar copolymer. Alternatively, an equation is proposed for calculating P ₁₂ P ^MAX ₂₁ from Q-e values. Uses and limitations of r ₁ r ₂ product in assessing alternation in binary copolymers are discussed.     

Side chain cholesteric liquid crystalline elastomers: synthesis and phase behaviour

A series of new side chain cholesteric liquid crystalline elastomers (P-2–P-6) containing the nematic crosslinking monomer 4-(10-undecen-1-yloyloxy)benzoyl-4′-allyloxybenzoyl-p-benzenediol bisate (M-1) and the cholesteric monomer 4-cholesteryl 4-(10-undecen-1-yloyloxy)benzoate (M-2) were synthesized. The chemical structures of the monomers and elastomers obtained were confirmed by FTIR and ¹H NMR spectroscopy. Their liquid crystalline properties and phase behaviour were investigated by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction. The effect of the crosslinking units on phase behaviour is discussed. Elastomers containing less than 20?mol?% of the crosslinking units showed elasticity, reversible phase transitions and cholesteric Grandjean texture. The experimental results demonstrated that the glass transition and isotropization temperatures of P-2–P-6 increased with the increasing concentration of crosslinking unit M-1.