Polysiloxanes with chlorobenzyl groups as precursors of new organic‐silicone materials

Various polysiloxanes bearing chlorobenzyl side groups were synthesized by the hydrolytic polycondensation of the 73:27 mol/mol mixture of [2‐(4‐chloromethylphenyl)ethyl] methyldichlorosilane and [1‐(4‐chloromethylphenyl)ethyl] methyldichlorosilane followed by the cationic equilibration or coequilibration with octamethylcyclotetrasiloxane, D₄. 1,3‐Divinyltetramethyl‐disiloxane was used as the chain end blocker to obtain a vinyl–Si ended chlorobenzyl‐substituted polysiloxane. In some cases, the polymer was additionally treated with dimethylvinylchlorosilane to achieve full substitution of chain ends by the vinyl group. Cohydrolysis of the chlorobenzylic monomer mixture with dimethyldichlorosilane was also practiced. Multiblock copolymers were obtained by polyhydrosilylation of the α,ω‐divinylsilyl chlorobenzyl‐substituted polysiloxanes with α,ω‐dihydrosilyl polydimethylsiloxanes. All these polymers and copolymers containing reactive chlorobenzylic groups were demonstrated to be convenient precursors of functional polysiloxanes of potential practical use. Some specific functional groups, such as quaternary ammonium salt groups of biocidal activity or azobenzene groups making the polymer sensitive to external stimuli by light, may be readily generated on polysiloxane under mild conditions. The chlorobenzylic substituted polysiloxanes may be also used as macroinitiators of the atom transfer radical polymerization, to obtain polysiloxanes with grafted organic polymers, such as styrene, 4‐chloromethylstyrene, and n‐butylacrylate. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1682–1692, 2004     

Polyisophthalamides with heteroaromatic pendent rings: Synthesis,physical properties,and water uptake

A set of novel aromatic polyamides containing pyridine pendent groups was prepared from aromatic diamines and new monomers that are 5‐substituted derivatives of isophthalic acid bearing nicotinamide, isonicotinamide, or picolinamide groups. The polymers were obtained in high yield and high molecular weight by the phosphorylation method of polycondensation. They were characterized by spectroscopic and chromatographic methods and several of their properties were investigated. All of the polymers were soluble in polar aprotic solvents and gave films of good mechanical properties. Glass transition temperatures were higher than that of the reference polymer, poly(m‐phenyleneisophthalamide) (IP‐MPD), while the thermal resistance, defined by the initial decomposition temperature observed by thermogravimetry, was in the range 370–420 °C, lower by 30–70 °C than that of IP‐MPD. The presence of a pendent pyridine group and an additional amide side group per repeat unit made the polymers essentially amorphous and greatly improved their abilities to absorb water in comparison with nonsubstituted polyamides. Water uptake values up to 15% were observed at 65% relative humidity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5300–5311, 2005     

Exactly alternating silarylene–siloxane polymers. VII. Thermal stability and degradation behavior of p-silphenylene–siloxane polymers with methyl,vinyl, hydrido,and/or fluoroalkyl side groups

The thermal stability and degradation behavior of a series of nine different exactly alternating silphenylene-siloxane polymers which contained methyl, vinyl, hydrido, 3,3,3-trifluoropropyl, and tridecafluoro-1,1,2,2-tetrahydrooctyl side groups, or their combinations, were investigated by dynamic and isothermal gravimetric analyses in air and in nitrogen. Two distinctly different mechanisms were observed in these atmospheres: a complex multi-step weight loss process in air and a single-step process in nitrogen. In nitrogen all polymers produced black, insoluble, highly stable degradation residues which were characterized by high carbon content. In contrast, in air the nonfluorine containing polymers degraded to pure silica, while the fluoroalkyl substituted polymers may have formed fluorosilicates of unspecified structures. There appears to be no significant molecular weight effect on the thermal stability of these polymers, at least not above an M _w value of about 35,000. Isothermal investigations indicate that 300°C in air and 350°C in nitrogen may be possible upper use temperatures for the methylvinyl substituted, exactly alternating silphenylene–siloxane polymers for extended periods of time. A strong thermostabilizing effect by vinyl side groups on the degradation behavior of these polymers was established. The extent of stabilization depends on the content of vinyl units, but it can already be clearly seen at the 5 mol % vinyl level, and it increases exponentially with increasing vinyl concentration. In contrast to this behavior, by comparison with the parent all-methyl substituted, exactly alternating silphenylene–siloxane polymers, the hydrido and fluroalkyl side groups reduce overall polymer thermal stability in terms of the degradation onset temperature, the temperature for 50% weight loss, and the amount of degradation residue. The presence of these groups also extends the later stages of the degradation processes to higher temperatures. Based on these and previous results, an order of stability is proposed as a function of the type of the substituent side groups for the thermal degradation of these polymers.     

Synthesis of wholly aromatic polysulfonamides from aromatic disulfonyl chlorides and aromatic diamines

Wholly aromatic polysulfonamides of high molecular weight were prepared by the solution poly-condensation of aromatic disulfonyl chlorides with aromatic diamines in tetramethylene sulfone and substituted pyridines as the acid acceptor. Polysulfonamides with inherent viscosities as high as 1.2 were readily obtained by initiating polycondensation at a temperature of 5–10°C to control the side reactions. The polycondensation was fairly fast and was completed in 10 min at 60°C. All the aromatic polysulfonamides dissolved in a wide range of solvents, including acetone and tetrahydrofuran. These polymers were less thermally stable than the corresponding aromatic polyamides.     

Vinyl‐Type Polymerization of Norbornene Dicarboxylic Acid Dialkyl Esters

Summary: Poly(cis‐norbornene‐exo‐2,3‐dicarboxylic acid dialkyl esters) (alkyl = Me, Et, Pr, Bu, Pen, and Hex) are synthesized as a vinyl‐type with a palladium(II ) catalyst in high yield from easily prepared, pure exo‐monomers. The polymers show good solubility in common organic solvents and excellent thermal stability up to 330 °C. The polymers with alkyl groups larger than methyl exhibit a two‐step thermal degradation profile of an initial thermal degradation of side‐chains starting at 350 °C, followed by thermal degradation of the norbornene backbone starting at ca. 430 °C. The glass transition temperature decreases and the mechanical flexibility increases as the alkyl length of the side‐chain increases.

Normalized loss shear modulus (G″) versus temperature for polynorbornene dicarboxylic acid dialkyl esters.     

Synthesis and characterization of ultraviolet‐curable hyperbranched poly(siloxysilane)s

Two UV‐curable hyperbranched poly(siloxysilane)s ( I and III ) containing vinyl and allyl end groups were synthesized via polyhydrosilylation with methylbis(methylethylvinylsiloxy)silane and methylbis(dimethylallylsiloxy)silane monomers. A cationic UV‐curable hyperbranched polymer ( II‐Ep ) with epoxy end groups was prepared via the hydrosilylation of hyperbranched polymer II with Si? H terminated groups and glycidyl methacrylate, and II was also obtained via the polyhydrosilylation of AB₂‐type monomer methylvinylbis(methylethylsiloxy)silane. All hydrosilylation reactions were catalyzed by Pt/C or chloroplatinic acid. Three AB₂‐type monomers were synthesized via the hydrolysis of functional chlorosilane, which was prepared with Grignard reagents and dichlorosilane. The molecular structures of the polymers were characterized with ¹H NMR, Fourier transform infrared, and gel permeation chromatography, and the UV‐curing behaviors of the polymers under different atmospheres and with different photoaccelerators were also investigated. The thermostability of uncured and cured polymers was examined with thermogravimetric analysis, and the data indicated that the orders of the onset decomposition temperatures for the cured polymers and the residue weights were as follows: III (380 °C) > I (320 °C) > II‐Ep (280 °C) and I (70.4%) > III (64.1%) > II‐Ep (60.9%), respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1883–1894, 2005     

可紫外光固化的超支化聚硅氧烷合成及固化研究

同线型聚硅氧烷聚合物相比，超支化聚硅氧烷聚合物具有低粘度、高反应活性和良好的相容性等特点，其中以制备超支化的聚硅氧烷基硅氧烷和聚烷氧基硅氧烷为主．对于超支化聚硅氧烷主要是以ABx（X=2～6）（其中A为双键，B为硅氢键）型单体为原料，在氯铂酸或Pt／C的催化下，通过硅氢加成反应一步制备，最终聚合物的端基（B）为硅氢键，而双键则完全反应，此外也可通过含不同数目烷氧基硅烷的水解缩合制备超支化聚硅氧烷．     

Bismaleimides chain-extended by imidized benzophenone tetracarboxylic dianhydride and their polymerization to high temperature matrix resins

Heat-resistant polymers were obtained by thermal polymerization of several bismaleimides or their substituted derivatives. The chain of the polymer precursors was extended by incorporation of imidized benzophenone tetracarboxylic dianhydride between the maleimide rings in order to impart a degree of flexibility in the polymers. The bismaleimides and their corresponding tetraamic acids were characterized by infrared (IR) and proton nuclear magnetic resonance (¹H-NMR) spectroscopy. The differential thermal analysis (DTA) thermograms of the monomers showed exotherms at 200–340°C attributed to the thermally induced polymerization reactions. The influence of different substituents in the maleic double bond on the curing temperature was investigated. The thermal stability of the cured resins was evaluated by thermogravimetric analysis (TGA) and isothermal gravimetric analysis (IGA). They were stable up to 367–433°C both in nitrogen and air atmosphere and afforded 57–68% char yield at 800°C under anaerobic conditions. The structure of the aromatic and aliphatic diamines utilized for imidization was correlated with the thermal stability of the cured resins. The bismaleimide derived from p-phenylenediamine gave the most heat-resistant resin because of its higher rigidity.     

Benzobistriazolophenanthroline polymers

The polycondensation of aromatic dihydrazidines (bisamidrazones) with 1,4,5,8-naphthalenetetracarboxylic acid or 1,4,5,8-naphthalenetetracarboxylic dianhydride in polyphosphoric acid led to high yields of soluble benzobistriazolophenanthroline polymers. Inherent viscosities in methanesulfonic acid of 0.25–2.51 dl g were recorded. Prior to polymer synthesis, a series of model compounds were prepared by reactions analogous to the polycondensation reaction. The polymer structure was established by elemental analysis and spectral comparisons of the polymers with model compounds. The thermal properties of the polymers were studied by thermal gravimetric analysis, differential thermal analysis, differential scanning calorimetry, and softening under load. Onset of breakdown in an air atmosphere occurs in the 440–450°C range. No softening under load was observed up to 450°C.     

Coordination Polymers. 9. Chelate Polymers Derived from Bisphenolic Complexes and Propylenediamine

Chelate polymers derived from bis(2,4-dihydroxybenzaldehyde)propyl-enediimine M and bis(2,4-dihydroxyacetophenone)propylenediimine M (M = Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺) with aromatic acid chlorides were prepared by interfacial polycondensation. Also, chelate polysiloxanes were obtained from the same monomers and α,ω-dichloropolydimethyl-siloxane. The spectral, thermal, magnetic, and electrical properties of the polychelates were studied.     

Synthesis and characterization of phosphonate‐containing polysiloxanes

Phosphonate‐functionalized polysiloxanes have been prepared with a new siloxane/phosphonate monomer. The reaction of 3‐chloropropylmethyldimethoxysilane with trimethylphosphite or triethylphosphite produces several new monomers containing pendant phosphonate groups. Copolymerization with dimethyldimethoxysilane has produced polymers soluble in most organic solvents. The acid hydrolysis of the phosphoryl esters has produced hydrophilic siloxane polymers containing phosphonic acid groups. The thermal properties of the polymers and several related small molecules have been compared with thermogravimetric analysis. Both the monomers and the resulting polymers have been characterized with ¹H, ¹³C, ³¹P, and ²⁹Si NMR. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 48–59, 2003     

Soluble aromatic poly(ether amide)s containing aryl‐, alkyl‐, and chloro‐substituted phthalazinone segments

A series of novel aromatic diamines ( 2 – 4 ) containing the alkyl‐, aryl, or chloro‐substituted group of phthalazinone segments were synthesized via two synthetic steps starting from 4‐(3‐R‐4‐hydroxyphenyl)‐2,3‐phthalazinone‐1 (R = Ph, CH₃, Cl). Three series of aromatic polyamides containing phthalazinone moieties were prepared through diamines 2 – 4 reacting with different aromatic dicarboxylic acids via a direct Yamazaki–Higashi phosphorylation polycondensation reaction. The resulting aromatic polyamides had inherent viscosities in the range of 0.40–0.76 dL/g. The thermal property of the polyamides was examined with DSC and thermogravimetric analysis. The glass‐transition temperatures of these polyamides ranged from 298 to 340 °C. The 10% mass‐loss temperature was above 405 °C under nitrogen. Structures of monomers 2 – 4 and the polymers were confirmed by Fourier transform infrared spectroscopy, ¹H NMR, and mass spectrometry. Good solubility of these polymers in polar solvents such as N‐methylpyrrolidone, dimethylformamide, dimethylacetamide (DMAc), and m‐cresol was observed, and tough, flexible films were obtained from the polymer's DMAc solutions. The effect of the substituted group on the physical property of polymers was also investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2026–2030, 2004     

Synthesis and study of block copolycondensates containing polysiloxane and unsaturated polyester blocks in the chain. II. Poly(unsaturated esters-b-siloxanes) with blocks linked by Si?C bonds and poly(butadienes-b-siloxanes)

Poly(unsaturated esters-b-siloxanes) whose blocks are linked by Si? C bonds and poly(butadienes-b-siloxanes) have been obtained by polycondensation of ω,ω′-diepoxy polydimethylsiloxanes and ω,ω′-dicarboxylic poly(unsaturated esters). The reaction between polysiloxanes with Si? H end groups and allylepoxy has been studied; the resulting ω,ω-diepoxy polysiloxanes have the expected structure. The polycondensation of oligomers with, respectively, epoxy and carboxylic end groups has been studied and the optimal conditions established. The samples with Si? C bonds are not affected by hydrolysis in pure water. The poly(siloxanes-b-unsaturated esters) can be cured by UV light.     

Effect of a lateral substituent on the mesomorphic properties of ferroelectric side chain liquid crystalline polysiloxanes

The synthesis of side chain liquid crystalline polysiloxanes containing oligooxyethylene spacers and ( S )-2-methylbutyl 4-\[(4-oxybiphenyl-4-yl)carbonyloxy]-3-fluorobenzoate mesogenic side groups is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction measurements reveal liquid crystalline properties for all synthesized monomers and polymers. All three precursor olefinic monomers reveal cholesteric and smectic A phases. The olefinic monomer which contains two oligooxyethylene units in the spacer is the only one which reveals a twist grain boundary A phase and a blue phase, besides the cholesteric and smectic A phases. All three polysiloxanes present enantiotropic smectic A and chiral smectic C phases. The mesomorphic behaviours of the monomers and polymers are compared with those of the corresponding monomers and polymers without the lateral fluoro substituent. The results seem to demonstrate that incorporating a lateral fluoro substituent in the mesogenic cores of the monomers affects not only the mesophase thermal stability, but also the nature of the mesophases formed. However, incorporating a lateral fluoro substituent in the mesogenic cores of the polymers affects only the thermal stability of the mesophases formed. The lateral fluoro substituent has a more profound effect on the mesomorphic behaviour for the monomers than that for the polymers.     

The synthesis and properties of side‐chain liquid‐crystal polymers with a chiral center

The synthesis and mesomorphic properties of six monomers and six side‐chain liquid‐crystal polymers with a chiral center are described. The polysiloxanes were prepared by the hydrosilation of monomers with poly(hydromethylsiloxane)s. Most of the polymers exhibit a wide range of the chiral smectic C phase (SmC*). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1609–1617, 2000     

Polyanhydrides. XI. Poly(Ester-anhydride)s Derived from 4-Hydroxybenzoic Acid,Vanillic Acid,and Aliphatic Dicarboxylic Acids

ABSTRACT

Poly(ester-anhydride)s, PEA's, built up by 50 mol% ester and 50 mol% anhydride groups were prepared by polycondensation of 0,0′-bistrimethylsilyl 4-hydroxybenzoic acid and various α,ω- alkane-dicarbonylchlorides. The polycondensations were conducted either in bulk or in 1-chloronaphthalene. High yields (up to 94%) were obtained under both reaction conditions, but the higher inherent viscosities resulted from polycondensations in 1- chloronaphthalene. IR- and ¹³C NMR spectroscopy revealed that reaction temperatures above 200°C cause side reactions such as transacylation and transesterification. Analogous series of polycondensations were conducted with 0,0′-bistrimethylsilyl vanillic acid. The resulting PEA's were amorphous, whereas the PEA's derived from 4-hydroxybenzoic acid are semicrystalline.     

Synthesis,physical, and thermal properties of linear poly(dialkoxyphosphinyl-s-triazine)s

A novel class of linear poly(dialkoxyphosphinyl-s-triazine)s were prepared by interfacial or solution polycondensation reactions of various diamines such as ethylenediamine, hexamethy-lenediamine or bis(4-aminocyclohexyl)methane with 2-dialkoxyphosphinyl-4,6-dichloro-s-triazines. The latter were synthesized by reacting cyanuric chloride with an equimolar amount of trialkyl phosphite. The phosphorous-containing polymers were characterized by inherent viscosity measurements as well as by infrared (IR) and proton nuclear magnetic resonance (¹H-NMR) spectroscopy. The thermal properties of polymers were investigated by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). Pyrolysis of all polymers was exothermic. Polymers were stable up to 150–200°C both in nitrogen and air atmosphere. They afforded 16–42% char yield at 700°C under anaerobic conditions.     

Preparation of new poly(ether-amide-imide)s from 1,4-bis-[4-(trimellitimido)phenoxy]butane and aromatic diamines via direct polyamidation

Several new Poly(ether-amide-imide)s were prepared by direct polycondensation reactions of 1,4-bis-[4-(trimellitimido)phenoxy]butane with various aromatic diamine. Two direct polycondensation techniques were used: direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone/triphenyl phosphite/calcium chloride/pyridine and direct polycondensation in a tosyl chloride/pyridine/N,N-dimethylformamide system. All the monomers and polymers were fully characterized by means of FTIR, ¹H-NMR spectroscopy and elemental analyses and properties of the polymers including solution viscosity, thermal behavior and solubility were studied.     

Grafting of Polymers Having Pendant Peroxycarbonate Groups Onto Carbon Black and Postpolymerization of Vinyl Monomers

Abstract

Postpolymerization of vinyl monomers initiated by pendant peroxycarbonate groups of grafted polymer chains on carbon black (CB) was investigated. The grafting of polymers having pendant peroxycarbonate groups onto CB was achieved by the trapping of polymer radicals formed by the thermal decomposition of copolymers of t-butylperoxy-2-methacryloyloxyethyl-carbonate (HEPO) with vinyl monomers such as vinyl acetate (VAc), styrene (St) and methyl methacrylate (MMA). The copolymers having pendant peroxycarbonate groups were prepared by copolym-erization of HEPO with vinyl monomers using azo initiator under irradiation of UV light at room temperature. The amount of remaining pendant peroxycarbonate groups of the poly(VAc-co-HEPO)-grafted CB obtained from the reaction at 90°C was maximum and decreased above the temperature. Furthermore, the postpolymerization of vinyl monomers, such as St, MMA, and VAc was initiated in the presence of poly(VAc-co-HEPO)-grafted and poly(St-co-HEPO)-grafted CB and the corresponding polymers were postgrafted onto CB to give branched polymer-grafted CB. The percentage of poly(St)-postgrafting (proportion of post-grafted poly(St) to poly(MMA-co-HEPO)-grafted CB used) increased with increasing polymerization time, but became constant at 20% after 4 hours.     

氟取代聚芳醚酮低温合成及其结构研究

通过傅克酰基化反应合成4,4'-二(4-氟苯甲酰基)二苯醚、4,4'-二(五氟苯甲酰基)二苯醚、4,4'-二(4-氟苯甲酰基)二苯硫醚以及4,4'-二(五氟苯甲酰基)二苯醚4种长链双卤单体,并进一步制备了含二氮杂萘酮聚芳醚酮聚合物.通过多氟取代双卤单体在含二氮杂萘酮聚芳醚酮聚合物主链中引入氟原子.多氟取代双卤单体具有多...