Sulfone/ester polymers containing pendent ethynyl groups

Sulfone/ester polymers containing pendent ethynyl groups were prepared by multistep and direct routes. Hydroxy-terminated sulfone oligomers(M _n = 2650 and 8890 g/mol) were reacted with diacid chlorides to yield high-molecular-weight polymers. In the multistep route, a pendent bromo group on the polymer was converted to an ethynyl group. In the direct route, the hydroxy-terminated sulfone oligomers were reacted with a stoichiometric amount of 5-(4-ethynylphenoxy)isophthaloyl chloride to yield high polymers. The pendent ethynyl groups on the sulfone/ester polymers were reacted in the 200 to 300°C range to provide branching and crosslinking. The resultant polymers exhibited higher T_gs and better resistance to chloroform than comparable polymers void of ethynyl groups. Films of the cured polymers displayed good mechanical properties. The synthesis and characterization of the monomer, oligomers, and polymers are discussed.     

Thermostable organic polymers devoid of hydrogen and other pendent groups

Aromatic hydrogen atoms in thermostable polymers can be surprisingly labile at relatively low temperatures and may participate extensively in degradative reactions. If hydrogen were eliminated from the polymer chain, a number of degradative pathways would be excluded. Replacement of hydrogen with other pendent groups such as fluoride or trifluoromethyl still leaves a potential “handle” to enter into unwanted reactions, therefore, all bonds not required to create the chain were eliminated. The polyimide devoid of hydrogen from pyrazinetetracarboxylic dianhydride and 2,5-diamino-1,3,4-thiadiazole was synthesized. This polymer exhibits extraordinary high temperature oxidation stability. Films of this composition support weight in air up to 592°C, and rupture at this temperature is accompanied by no charring whatever. By comparison, the corresponding polymer from pyromellitic dianhydride, with two hydrogen atoms per repeating unit begins to char at 320°C.     

Preparation and characterization of bismaleimides containing ester groups from bisphenolic chelates and their polymers

A series of novel metal‐containing bismaleimide monomers was prepared by the reaction of 4‐maleimidobenzoic acid chloride with bisphenolic chelates. By reaction of the synthesized bismaleimides with bis(1‐mercapto‐2‐ethylether) or 3,4‐dichloromaleimidobenzoic acid chloride, new chelating polyimidosulfides and poly(ether‐ester)maleimides were prepared. The structures of the bisphenols, bismaleimides and polymers obtained were confirmed by IR spectroscopy and elemental analysis. Characterization of the compounds was undertaken by differential scanning calorimetry, thermooptical analysis, thermogravimetric analysis, viscosity measurements and solubility tests. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis and characterization of aromatic polyamides containing alkylphthalimido pendent groups

A series of polyisophthalamides containing pendent phthalimido groups and flexible side spacers were prepared from four novel diacids and three commercial aromatic diamines. These polyamides were prepared in high yields and with high molecular weights by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 70,000–137,000 and 47,000–86,000 g/mol, respectively. The novel polyamides were amorphous and readily soluble and showed glass‐transition temperatures of 150–240 °C, as measured by differential scanning calorimetry. Thermogravimetric analysis showed that the 10% weight‐loss temperatures in nitrogen were 355–430 °C, a significant improvement in thermal stability having been observed with the increase in the side‐chain length. A theoretical quantum mechanical study was successfully carried out to explain these results. Flexible and tough films, cast from polymer solutions, showed tensile strengths of 50–125 MPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3711–3724, 2002     

Reduction of pendent ester groups in polycarbonates by use of diborane

A series of polycarbonates with pendent ester groups have been synthesized. These ester groups have been converted to hydroxyl functionalities by reduction with diborane in tetrahydrofuran. The number of methylene groups in the pendent chain has a large effect on the reducibility of the ester.     

Plasma polymers containing sulfonate groups

Modification of plasma-polymers prepared from phenylsilane with sulfur trioxide was investigated by FT/IR spectroscopy and ESCA. The sulfonation of phenyl groups in the plasma-polymers occurred rapidly within 1 min when exposed to SO₃ gas. The S/C and O/C atomic ratios determined by ESCA for the modified polymers were 0.13₈ and 0.41₈, respectively. The sulfonation made the plasma-polymers electrically conductive. The conductivity was sensitive to moist atmosphere. The logarithm of the impedance at 120 Hz decreased linearly with increasing the relative humidity. The plasma-films containing sulfonate groups may be a new material for moisture sensor devices.     

Crosslinked polymers containing adamantane groups

Diglycidyl ethers of 1,3-bis-(p-hydroxyphenyl)adamantane (BHPA) and 3,3'-bis-(p-hydroxyphenyl)-1,1'-biadamantane (BHPBA) were prepared and condensed with m-phenylenediamine and methyl tetrahydrophthalic anhydride to give polymers with good high temperature mechanical properties and good oxidative stability. These bisphenols were also condensed with formaldehyde to give phenolic resins containing adamantane moieties.     

Poly(1,3,4-oxadiazole-amide)s containing pendent imide groups

A series of new poly(1,3,4-oxadiazole-amide)s containing pendent imide groups has been synthesized by solution polycondensation of aromatic diamines containing preformed 1,3,4-oxadiazole rings with two diacid chlorides containing imide rings. These polymers were also prepared by the reaction of the same diacid chlorides with p-aminobenzhydrazide which were subsequently cyclodehydrated in solid state. The polymers were soluble in polar amidic solvents and some of them gave transparent flexible films by casting from solutions. They showed high thermal stability with decomposition temperatures above 400°C and glass transition temperatures in the range of 245–327°C. They had low dielectric constants, in the range of 3.32–3.94, and good tensile properties.     

Synthesis and polycondensation of some new organotellurium compounds containing hydroxymethyl groups

A new series of organotellurium compounds [i.e. 2‐HOCH₂C₆H₄TeBr₃ (1), (2‐HOCH₂C₆H₄)₂TeBr₂ (2), (2‐HOCH₂C₆H₄)₂Te (3), (2‐HOCH₂C₆H₄Te? )₂ (4), 4‐HOCH₂C₆H₄TeBr₃ (5), (4‐HOCH₂C₆H₄)₂TeBr₂ (6), (4‐HOCH₂C₆H₄)₂Te (7), and (4‐HOCH₂C₆H₄Te? )₂ (8)] were prepared by reacting hydroxymethylphenylmercury chlorides with tellurium tetrabromide in dry dioxane. Bis(2‐hydroxymethylphenyl) telluride (3), bis(2‐hydroxymethylphenyl) ditelluride (4) and bis(4‐hydroxymethylphenyl) telluride (7) were polymerized by a solution polycondensation technique with toluene diisocyanate and terephthaloyl chloride, leading to new organic tellurium polyurethanes and polyesters. All the new compounds were characterized by elemental analysis and spectroscopic data. Copyright © 2002 John Wiley & Sons, Ltd.     

Self-Crosslinkable poly(arylene ether)s containing pendent phenylenetriazene groups

Self-crosslinkable poly(arylene ether)s 6 , and 8 , containing pendent triazene groups were prepared by nucleophilic substitution reaction of poly(arylene ether)s 5 , and 7 , respectively, with 1-[4-(4-hydroxyphenoxy)phenylene]triazenes, 4 , in the presence of potassium carbonate in N,N-dimethylacetamide. A series of triazenes 4 containing various substituents have been synthesized. Self-crosslinkable polymer 6e containing phenyl-substituted triazene pendants can be crosslinked at 215°C, which is about 40°C lower than the glass transition temperature of the virgin base polymer 5 . The degree of crosslinking can be tailored by varying the concentration of the pendent phenylenetriazene groups in the polymer. After curing, the flexible polymer films (ca. 10 μm thick) exhibit high gel contents, increased glass transition temperatures, improved resistance to organic solvents, and little change in dielectric constant and thermal stability. These self-crosslinkable poly(arylene ether)s are potential candidates for electronic applications. © 1994 John Wiley & Sons, Inc.     

The photochemistry of polymers containing anthrylmethyl vinyl ketone

The photolysis of copolymers of anthrylmethyl vinyl ketone (AMVK) with styrene and methyl methacrylate has been studied, both in solution and in the solid phase. Quantum yields of the order of 0.01 were observed in both cases for release of the major product, methyl anthracene (MA). Photolysis of an aqueous emulsion of a styrene-AMVK copolymer showed similar yields of MA. The results indicate the possibility of using the Norrish type I process as a means of releasing drugs or other biologically active compounds from polymeric matrices. © 1995 John Wiley & Sons, Inc.     

Self-organizing cyclolinear methylcyclohexasiloxane polymers carrying reactive vinyl groups

Atactic cyclolinear organosilicon polymers containing vinyl substituents in RSiO_1.5, R₂SiO or both moieties have been synthesized through the heterofunctional polycondensation of trans,cis-2,8-dihydroxymethyl(vinyl)cyclohexasiloxanes with 2,8-dichloromethyl(vinyl)cyclohexasiloxanes. The structure of the polymers has been studied by ¹H and ²⁹Si NMR and IR spectroscopy, molecular mass measurements, and elemental analysis. The phase behavior of these copolymers in the bulk has been examined by DSC, X-ray diffraction, and polarization optical microscopy. It has been shown that the copolymer can exist in the mesomorphic state in the temperature range from ?100 to +200°C. The X-ray data indicate changes in the interlayer spacing and the type of packing of cyclolinear poly(methylvinylsiloxanes) with an increase in the content of vinyl substituents in the repeating units of the polymer. The ability of cyclolinear poly(methylvinylsiloxanes) to spread over the water/air interface and to form mono-and multilayers has been investigated. As the content of vinyl substituents in the polymer unit is increased to two or four, the ability of polymers to form multilayers is preserved. The incorporation of vinyl substituents into RSiO_1.5 or R₂SiO moieties of polymer units is accompanied by the formation of monolayers.     

Organosilane polymers: Formable polymers containing reactive side groups

Formable organosilane polymers containing various reactive side groups were synthesized by hydrosilylation of unsaturated compounds containing reactive groups with poly(methylsilane) in the presence of platinum complexes. These polymers have appreciable solubility in common solvents, can be molded or cast into films or drawn into fibers, and are photoactive.     

Synthesis and properties of cyclolinear methylcyclotetrasiloxane polymers with vinyl groups

Atactic cyclolinear organosilicon polymers carrying vinyl groups in RSiO_1.5 or R₂SiO moieties or concurrently in two moieties of the polymer unit have been synthesized by the heterofunctional polycondensation of 2,6-dihydroxymethyl(vinyl)cyclotetrasiloxanes with 2,6-dichloromethyl(vinyl)cyclotetrasiloxanes. The structure of the polymers has been studied by ¹H and ²⁹Si NMR spectroscopy, IR measurements, and elemental analysis. According to DSC, X-ray diffraction, and polarization optical microscopy, the polymers are amorphous in the range from ?100 to +200°C; the interlayer spacing and the type of packing remain unchanged with an increase in the content of vinyl substituents in the repeating units of cyclolinear polymethylvinylsiloxanes.     

Cinnamate ester containing liquid crystalline side chain polymers

The synthesis of methacrylate esters of 4-cyanophenyl-(4-(ω-hydroxyalkyloxy)) cinnamates, with spacer lengths of 2 and 6 methylene units and the synthesis of the corresponding acrylate ester with a spacer of 2 methylene units are described. The methacrylate monomers were polymerized by free radical polymerization, both as homopolymers and as copolymers with the analogous benzoate monomer of spacer length 6. The acrylate ester could not be polymerized successfully under the same reaction conditions. Polymers were characterized by NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and thermo-optic observations. Of the monomers prepared, only the cinnamate with a hexamethylene spacer shows a mesophase, seen on supercooling of the melt. All of the polymers prepared were liquid crystalline, with smectic behavior predominating in the polymethacrylates with the longer spacer group. A narrow nematic region is seen just below the clearing temperature with a range of 3–9°C, nematic character is increased in the copolymer series with the degree of incorporation of the cinnamate monomer with the spacer group of length 2.     

Monolayers of methacrylic polymers containing aromatic groups

Monolayers of poly-methacrylates containing either aromatic or linear side groups were studied at the air-water interface. The aim of the work is to define the role of the aromatic group in determining the interfacial distribution and orientation of these polymers. Surface pressure measurements show that all the polymers give stable expanded monomolecular films between 288 K and 308 K temperature range.Surface potential and ellipsometric measurements show that both aromatic and aliphatic polymers are in an almost horizontal conformation at the liquid-air interface. From a comparison of the experimental isotherms with Huggins' theory, it was deduced that no preferential interactions exist between benzene rings in the film. In contrast, preferential attractive energies are observed for n-alkylmethacrylates.Further information on the state of the collapsed film was obtained from electron scanning micrographs.     

Poly(methyl methacrylate) copolymers containing multiple,pendent plasticizing groups

New ether dimer (ED‐Eh) and diester (EHDE) derivatives of α‐(hydroxymethyl)acrylate, each having two 2‐ethylhexyl side chains, and an amine‐linked di(2‐ethylhexyl)acrylate (AL‐Eh), having three 2‐ethylhexyl side chains, were synthesized and (co)polymerized to evaluate the effects of differences in the structures of the monomers on final (co)polymer properties, particularly glass transition temperature, T_g. The free radical polymerizations of these monomers yielded high‐molecular–weight polymers. Cyclopolymer formation of ED‐Eh and AL‐Eh was confirmed by ¹³C NMR analysis and the cyclization efficiencies were found to be very high (～100%). Copolymers of ED‐Eh, EHDE, and AL‐Eh with methyl methacrylate (MMA) showed significant T_g decreases over poly(methyl methacrylate) (PMMA) due to 2‐ethylhexyl side groups causing “internal” plasticization. Comparison of the T_g's of the copolymers of 2‐ethylhexyl methacrylate, ED‐Eh, EHDE, and AL‐Eh with MMA revealed that the impacts of these monomers on depression of T_g's are identical with respect to the total concentration of the pendent groups. This is consistent with an earlier study involving copolymers of monomers comprising one and two octadecyl side groups with MMA. That is, the magnitude of decrease in T_g's was quantitatively related to the number of the 2‐ethylhexyl pendent groups in the copolymers rather than their placement on the same or randomly incorporated repeat units. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2302–2310, 2010