Synthesis,polymerization, and curing of N‐substituted citraconimidyl acrylate

Several N‐(substituted phenyl) citraconimides containing phenolic hydroxyl groups (I) were prepared. I were esterified with acryloyl chloride producing the corresponding acrylate esters (II). II were free radically polymerized yielding linear polyacrylates (III). The citraconimidyl vinyls did not participate in the polymerization. The resulting polymers (III) were cured thermally or through the crosslinking agent N,N‐(p‐phenylene)dimaleimide. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 427–433, 1999     

Polymers from renewable resources. XXI. Semi-interpenetrating polymer networks based on cardanol-formaldehyde-substituted aromatic compounds copolymerized resins and castor oil polyurethanes: Synthesis,structure, scanning electron microscopy and XRD

Substituted aromatic compounds incorporated–cardanol–formaldehyde novolac resins were synthesized by acid base catalyzed reactions. A number of improved high temperature stable interpenetrating polymer networks (semi-IPNs) were prepared by condensing novolac resins and polyurethanes prepared from castor oil and diisocyanates of varying NCO/OH ratio. The structure of these semi-IPNs were studied using various characterization techniques such as IR, nuclear magnetic resonance (NMR) spectra. The scanning electron microscopy of some of the semi-IPNs have been studied and the morphology has been examined. The samples were subjected to wide angle X-ray diffraction analysis. The degree of crystallinity (X_cr) was computed on the basis of the crystal defect concept, developed by Ruland and Vonk. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3117–3124, 1997     

Head‐to‐head polymers

Head‐to‐head (H–H) linkages were observed in addition and condensation polymers. Pure H–H polymers of polyolefins, poly(vinyl halides), and polyacrylates were prepared, and the fundamental polymer properties were determined. They included mechanical, spectral, thermal, and degradation behaviors. These properties were compared with those of the traditional head‐to‐tail polymers. Blends of H–H polymers were also studied. The thermal and thermal‐degradation behaviors of the blends were also investigated. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4013–4022, 2000     

Depth profiling of latex blends of fluorinated and fluorine‐free acrylates with laser‐induced secondary mass spectrometry

We explored phase separation and self‐assembly of perfluoroalkyl segments at the surface of polymer films obtained from latices of semifluorinated acrylate copolymers and the corresponding latex blends of nonfluorinated and semifluorinated polyacrylates. With laser‐induced secondary mass spectrometry the fluorine distribution was measured after annealing above the minimum film‐forming temperature of the polymers up to a depth of several micrometers. Depth profiles of a semifluorinated acrylate homopolymer and latex blends thereof with fluorine‐free alkylacrylates with 25, 50, and 75 mol % semifluorinated acrylate as well as a copolymer comprised of alkyl acrylate and semifluorinated acrylate (50/50 mol %) were investigated. In the case of latex blends containing both semifluorinated polyacrylates and fluorine‐free or low‐fluorine polymers, self‐assembly accounted for enrichment of the perfluoroalkyl segments at the surface. Coatings exhibiting low surface energy and having a substantially reduced total fluorine content were obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 360–367, 2003     

Synthesis of a hexafluoropropylidene-bis(phthalic anhydride)-based polyimide and its conducting polymer composites with polypyrrole

A new electrically conducting composite film from polypyrrole and 4,4′-(hexafluoroisopropylidene)-bis(phthalic anhydride)-based polyimide was prepared. Pyrrole and the dopant ion can easily penetrate through the polyimide substrate and electropolymerize on the platinum (Pt) electrode due to the swelling of the polyimide on the metal electrode. The electrochemical properties of polypyrrole-polyimide (PPy/PI) composite films have been investigated by using cyclic voltammetry. The PPy/PI composite film is suitable for use as the electroactive material owing to its stable and controllable electrochemical properties. The electrical conductivity of composites falls in the range 0.0035–15 S/cm. Scanning electron micrograph, FTIR, and thermal studies indicate that PPy and PI form a homogeneous material rather than a simple mixture. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3009–3016, 1997     

Photocrosslinkable vinylamine copolymers. I. Synthesis and photosensitivity of cinnamoylated polyvinylamine

Vinylamine copolymers prepared by the Hofmann reaction were functionalized by amidification with cinnamoyl chloride. The resulting photosensitive polymers, which are the nitrogen analogues of poly(vinylcinnamate), can be prepared with various contents of cinnamamide side groups. The polymers exhibit a marked hydrophilicity and undergo efficient crosslinking upon exposure to 250–300 nm UV light. The sensitivity S expressed in cm²·J⁻¹ was shown to be higher for a given content, τ, in cinnamamide groups expressed in mol·g⁻¹ when the residual vinyl amine units are in the ammonium form. The dependence of S upon τ was of the second order for the free base form of the photopolymers, but a higher order with S approximately proportional to τ³ for the hydrochloride form of the photosensitive polymers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2513–2520, 1997     

Syntheses of well-defined star-shaped poly(tetrahydrofuran) polyols by the ion-coupling method

The prepoly(tetrahydrofuran) [poly(THF)] capped with hydroxyl and tetrahydrothiophenium groups was prepared using tetrahydrothiophene to terminate the living cationic polymerization of THF initiated by BF₃·OEt₂ and epichlorohydrin (ECH) at low conversion. Well-defined star-shaped poly(THF) polyols were synthesized by an ion-coupling reaction of the prepoly(THF) with tri- or tetrafunctional benzenecarboxylates, respectively, and this process proceeded by precipitation when the solution of the prepolymer in THF was added to an aqueous solution containing an excess of the corresponding coupling reagent. GPC studies showed that all of the carboxylate groups of every coupling reagent molecule took part in the ion-coupling reaction simultanously. This was confirmed by IR spectra. Almost all of the prepolymers were coupled to form star polymers after repeating the precipitation four times. ¹H-NMR illustrated that both the star-shaped polymers and the prepolymers contained primary and secondary hydroxyl end groups. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3403–3408, 1997     

Synthesis and characterization of reactive liquid crystalline Schiff bases,Rh(I) complexes,and their derived polymers

Two series of salicylaldimines have been synthesized that consist of model compounds with terminal methylenic chains and reactive compounds in which the terminal chains have been modified with acrylate groups. The dicarbonylrhodium(I) complexes of these systems were prepared by reacting the ligands with the dimer [RhCl(cod)]₂ and CO. Characterization of the metal‐containing acrylates by ¹H NMR spectroscopy revealed that the Rh(I) can coordinate to the terminal double bond to produce pentacoordinated complexes. Furthermore, investigation of the mesogenic properties of the complexes revealed that the bulkiness of the metallic center requires the presence of at least a three‐ring aromatic core to avoid the suppression of liquid crystallinity. The study was extended to include the side‐chain polymers obtained from the acrylate‐functionalized Schiff bases. Chelation of the preformed polyacrylate with low percentages of Rh(I) emerged as the best strategy to prepare Rh(I)‐containing polyacrylates. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4466–4477, 2000     

Solution properties,unperturbed dimensions,and chain flexibility of poly(1‐adamantyl acrylate)

Poly(1‐adamantyl acrylate) (PAdA) exhibits much higher glass transition and degradation temperatures than other polyacrylates. However, the quantitative evaluation of the stiffness of this polymer chain has not been reported previously. In this study, the dilute solution properties and conformational characteristics of PAdA were evaluated using viscometry and scattering techniques. The unperturbed dimensions of this polymer were evaluated using the Burchard–Stockmayer–Fixman extrapolation and the touched‐bead wormlike chain model. The PAdA chain has a comparable persistence length, diameter per bead and characteristic ratio to poly(methyl methacrylate) and polystyrene. All these results indicate that PAdA is less flexible than common polyacrylates. In addition, the second virial coefficients (A₂) of PAdA in different solvents obtained by static light scattering were compared. Among the solvents investigated, tetrahydrofuran is a moderate solvent. Radius of gyration of a polymer sample in the various solvents ranged from 16.8 to 30.3 nm. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1526–1531     

Direct transesterification of poly(methyl acrylate) for functional polyacrylate syntheses

Post‐polymerization modification is an important synthetic method to produce macromolecules with various chemical and physical properties. With this technique, functional groups of polymer molecules within the same structural scaffold can be varied, and thus, accurate research on structure‐property relationships is possible. To add practicality, the direct post‐polymerization of commodity polymers has been pursued, but only limited success has been realized. In this report, a study on various transesterification methods for the synthesis of functional polyacrylates beginning with a poly(methyl acrylate) (PMA), one common acrylate polymer, is presented. The Zn‐based catalytic system, a combination of Zn₄(OCOCF₃)₆O and 4‐dimethylaminopyridine with instant methanol removal, exhibited the highest reactivity among many catalysts and conditions. Assorted alcohols were reacted with PMA to produce the corresponding polyacrylates. This method was successfully extended to post‐polymerization modification of a PMA‐containing block copolymer, PS‐b‐PMA and synthesis of acrylate copolymers with functional group density control. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2554–2560     

Prediction and estimation of solvent diffusivities in polyacrylate and polymethacrylates

The relationship between polymer side‐chain length and the hole free volume that is effective for solvent diffusion was investigated for polyacrylates and polymethacrylates on the basis of free‐volume theory. Measurements of a polymer's viscoelasticity and solvent diffusivity provided experimental evidence for polymer segment mobility, and the results indicated that hole free volume in a linear polymer increases with hydrocarbon side‐chain length. Because the molecular mechanisms of polymer viscoelasticity and diffusivity are identical, the free‐volume parameters obtained for polyacrylates and polymethacrylates by measuring the polymer viscoelastic‐temperature dependence can reliably be used in predicting the solvent diffusion coefficient. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1393–1400, 2003     

All hydrocarbon main‐chain thermotropic liquid crystalline polymers,poly(1,1′‐biphenylene‐4,4′‐alkenediyl)s,prepared by the ADMET method and their hydrogenated polymers,poly(1,1′‐biphenylene‐4,4′‐alkanediyl)s

A series of poly(4,4′‐biphenylenealkenylene)s and copolymers were prepared by the acyclic diene metathesis (ADMET) polymerization of 4,4′‐bis(alkenylene)1,1′‐biphenyls. Unsaturated polymers thus prepared were then hydrogenated to produce the corresponding saturated polymers. All the polymers were found to be thermotropic and to form solidlike smectic phases in melt. Their liquid crystallinity (LC) was studied by differential scanning calorimetry (DSC), X‐ray diffractometry, and polarizing microscopy. We observed that one of the phenylene units of the biphenyl structure could selectively be hydrogenated at an elevated temperature. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1335–1349, 2004     

Photochemical behavior of poly(ethylacryloylacetate) and poly(acryloylacetone) films

Films of poly(ethylacryloylacetate) (PEAA) and poly(acryloylacetone) (PAA) were subjected to UV irradiation (λ = 254 nm) at room temperature. The photoinduced structure transfer from cis-enol onto a diketo forms has been investigated. The structure transfer caused by UV light was found to be slower than for the corresponding process in solution. The spectral investigations (UV, IR) showed reversible process of photoketonization. The results were analyzed in terms of the model for the participation of the trans-enol form in the process of the ketonization. Based on the results obtained, some general conclusions were made about the organization of the units in the polymer chain. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3683–3688, 1997     

Thermally and oxidatively stable thermosets derived from preceramic monomers

Monomers 1,3-bis(4-phenylethynylphenyl)tetramethyldisiloxane and 1,7-bis(4-phenylethynylphenyltetramethyldisiloxyl)-m-carborane were synthesized and compared with bis(4-phenylethynylphenyl)dimethylsilane as potential preceramic precursors. These monomers were heated to free flowing liquids above 100°C and thermally polymerized above 300°C to form heat-resistant thermosets or ceramic residues. The ceramic yields for the silane (13%) and siloxane (30%) were much lower than that for the carborane (64%) monomer. The thermoset and ceramic made from the carborane monomer were the best thermally and oxidatively stable materials. After curing, the thermoset had a weight loss of only 6% and after pyrolysis, the ceramic residue had no additional weight loss up to 1000°C in air. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1033–1038, 1997     

Three-component coupling polymerization of bisallene,aryl dihalides,and nucleophiles via π-allylpalladium complex. II. Effect of nucleophiles on polymerization

A novel palladium-catalyzed three-component polycondensation of 1,2,10,11-dodecatetraene, 4,4′-diiodobiphenyl, and nucleophiles was carried out using various carbanions and amines as a nucleophilic part. The polymerization with various sodium diethyl malonates produced polymers in high yields. Particularly, no exo-double bond was detected in the polymers prepared from sodium diethyl malonates bearing substituents directly on the carbanion center. The ratios of E- and Z- isomeric units in the polymers were dependent on the structure of the nucleophiles used. Other carbanions with appropriate electron-withdrawing groups such as sulphones and ketones can be also used as a nucleophile for the present polycondensation. Within heteronucleophiles examined, cyclic amines were suitable to produce polymers in high yields. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1211–1218, 1997     

Immiscibility,upper critical solution temperature,and miscibility in blends of poly(vinyl ether)s with polyacrylics: Effects of pendant groups

Various phase behavior of blends of poly(vinyl ether)s with homologous acrylic polymers (polymethacrylates or polyacrylates) were examined using differential scanning calorimetry, optical microscopy (OM), and Fourier‐transformed infrared spectroscopy. Effects of varying the pendant groups of either of constituent polymers on the phase behavior of the blends were analyzed. A series of interestingly different phase behavior in the blends has been revealed in that as the pendant group in the acrylic polymer series gets longer, polymethacrylate/poly(vinyl methyl ether) (PVME) blends exhibit immiscibility, upper critical solution temperature (UCST), and miscibility, respectively. This study found that the true phase behavior of poly(propyl methacrylate)/PVME [and poly(isopropyl methacrylate)/PVME)] blend systems, though immiscible at ambient, actually displayed a rare UCST upon heating to higher temperatures. Similarly, as the methyl pendant group in PVE is lengthened to ethyl (i.e., PVME replaced by PVEE), phase behavior of its blends with series of polymethacrylates or polyacrylates changes correspondingly. Analyses and quantitative comparisons on four series of blends of PVE/acrylic polymer were performed to thoroughly understand the effects of pendant groups in either polyethers (PVE's) or acrylic polymers on the phase behavior of the blends of these two constituents. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1521–1534, 2007     

Temperature-induced phase transition of poly(N,N-dimethylaminoethyl methacrylate-co-acrylamide)

Copolymers of N,N-dimethylaminoethyl methacrylate (DMAEMA) and acrylamide (AAm) were prepared to demonstrate a temperature-induced phase transition. Poly DMAEMA has a lower critical solution temperature (LCST) around 50°C in water. With copolymerization of DMAEMA with AAm, the LCST shifts to the lower temperature was observed, probably due to the formation of hydrogen bonds between amide and N,N-dimethylamino groups. FT-IR studies clearly show the formation of hydrogen bonds which protect N,N-dimethylamino groups from exposure to water and result in a hydrophobic contribution to the LCST. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys, 35: 595–598, 1997     

Polymer-supported reagents. II. Kinetics of esterification of acrylic acid with n-butanol using polymer supported titanium tetrachloride as catalyst

Crosslinked poly(4-vinylpyridine-co-styrene) was prepared and functionalized with titanium tetrachloride to afford the corresponding poly(4-vinylpyridine-co-styrene)-titanium tetrachloride complex. This insoluble functionalized polymer-supported catalyst shows good catalytic activity for esterification reactions. In this article, the kinetics of esterification of acrylic acid with n-butanol is reported. The rate of formation of product depends on many experimental parameters, viz., stirring speed, concentration of acrylic acid, catalyst amount, temperature, percent active site, percent crosslinking, and mesh size of the polymer catalyst. The reaction rates were found to increase with increase in the stirring speed, concentration of acrylic acid, catalyst amount, and temperature, and decreases with increasing percentage crosslinking and mesh size of the polymer beads. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 727–733, 1997     

Permeation of nitrogen and water vapor through sulfonated polyetherethersulfone membrane

The novel polyetherethersulfone (PES-C) prepared from phenol-phthalein in our institute is an amorphous, rigid, tough material with good mechanical properties over a wide temperature range. To improve its water vapor permeability for the application of gas drying, the PES-C was sulfonated with concentrated sulfuric acid and transferred in sodium, cupric, and ferric salt forms. The sulfonation degree can be regulated by controlling the temperature and reaction time. Characterization of sulfonated PES-C in sodium form was made by IR. Some properties of the sulfonated PES-C, such as solubility, glass transition temperature, thermal stability, mechanical properties, and transport properties to nitrogen and water vapor have also been discussed. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2133–2140, 1997