New fluorinated polysiloxanes containing an ester function in the spacer. I. Synthesis and characterization

Unsaturated perfluoroalkyl esters derived from undecylenic acid: CH₂?CH? (CH₂)₈? COO? CH₂? CH₂? R_F (with R_F?C₆F₁₃, 2a and R_F?C₈F₁₇, 2b ) and C₈F₁₇? (CH₂)₁₀? COO? CH₂? CH?CH₂, 2c were prepared with excellent yields. Their hydrosilylation by methylhydrodimethylsiloxane copolymers of various Si? H contents gives new fluorinated polysiloxanes which were examined by ¹H- and ¹³C-NMR, GPC, differential scanning calorimetry, and optical polarizing microscopy. Polymers derived from compounds 2a and 2b exhibit mesomorphic structures. © 1994 John Wiley & Sons, Inc.     

Synthesis of water‐soluble zwitterionic polysiloxanes

A series of water‐soluble siloxane polymers with pendent phosphorylcholine (PC) and sulfobetaine (SB) zwitterions was prepared using thiol‐ene “click” chemistry. Specifically, well‐defined vinyl‐substituted siloxane homopolymers and block copolymers were functionalized with small molecule zwitterionic thiols at room temperature. Rapid and quantitative substitution of the pendent vinyl groups was achieved, and zwitterionic polysiloxanes of narrow molecular weight distribution were obtained. The PC‐ and SB‐substituted polymers were found to be readily soluble in pure, salt‐free water. Critical micelle concentrations (CMCs) of these polymers in water were measured using a pyrene fluorescence probe, with CMC values estimated to be <0.01 g/L. Polymer aggregates were studied by dynamic light scattering, and the micelles generated from the PC block copolymers were visualized, after drying, by transmission electron microscopy. Aqueous solutions of these zwitterionic polysiloxanes significantly reduced the oil‐water interfacial surface tension, functioning as polymer amphiphiles that lend stability to oil‐in‐water emulsions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 127–134     

Well‐defined phosphonate‐functional copolymers through RAFT copolymerization of dimethyl‐p‐vinylbenzylphosphonate

Dibenzyltrithiocarbonate‐mediated RAFT polymerization of dimethyl‐p‐vinylbenzylphosphonate and its copolymerization with styrene are studied in order to access well‐defined statistical and block copolymers containing controlled amounts of dimethylphosphonate groups. NMR and SEC analysis of the (co)polymers confirm the controlled character of the polymerizations. ABA triblock copolymers are treated with TMSiBr/MeOH in order to transform the dimethylphosphonate groups into phosphonic acids while keeping the midchain trithiocarbonate group and triblock nature unaffected. Alternatively, the combination of trithiocarbonate aminolysis with TMSiBr/MeOH treatment of the same triblock copolymers leads to phosphonic acid‐functional diblock copolymer counterparts. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2616‐2624     

Synthesis and characterization of chiral liquid‐crystalline polysiloxanes containing fluorinated units and sulfonic acid groups

Chiral side‐chain liquid‐crystalline polysiloxanes ( PS‐1 , PS‐2 , PS‐3 , PS‐4 , PS‐5 , PS‐6 ) bearing fluorinated units and sulfonic acid groups were synthesized with poly(methylhydrogeno)siloxane, cholest‐5‐en‐3‐ol(3β)‐4‐(2‐propenyloxy)benzoate, and 3‐trifluoromethyl‐phenyl 3‐sulfo‐4‐undec‐10‐ enoyloxy‐benzoate. The effects of fluorinated units and sulfonic acid groups on characteristic of liquid‐crystalline properties were studied. PS‐1 , PS‐2 , and PS‐3 exhibited both smectic and cholesteric mesophases, while PS‐4 , PS‐5 , and PS‐6 exhibited only cholesteric mesophase. As the polymers contained more fluorinated units and sulfonic acid groups, segregation of the fluorinated segment to the surface and aggregation of hydrogen bonding should occur. Therefore, the highly ordered lamellar mesogen–siloxane matrix systems should be disturbed severely, suggesting that PS‐4 , PS‐5 , and PS‐6 show no smectic phase. The maximum reflection bands become broad and shifted slightly to long wavelength from PS‐1 to PS‐6 . Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis and characterization of alt‐copoly(carbosiloxane)s containing oligodiphenylsiloxane segments

Novel α,ω‐divinyloligodiphenylsiloxanes (1,9‐divinyldecaphenylpentasiloxane, 1,7‐divinyloctaphenyltetrasiloxane, 1,5‐divinylhexaphenyltrisiloxane, and 1,3‐divinyltetraphenyldisiloxane) were prepared and copolymerized by Pt‐catalyzed hydrosilylation with α,ω‐dihydridopentasiloxanes. The molecular weights of the copolymers were measured with gel permeation chromatography, and their thermal properties were characterized with differential scanning calorimetry and thermogravimetric analysis. The polymers had high thermal stability in air and nitrogen. The oligomer and polymer structures were determined with ¹H, ¹³C, ¹⁹F, and ²⁹Si NMR and IR spectrometry. The molecular weights of the oligomers were measured with high‐resolution mass spectrometry. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2155–2163, 2005     

Synthesis and characterization of novel phosphoramidates containing benzimidazole moiety

Novel heterocyclic phosphoramidates were synthesized by a nucleophilic substitution reaction of 2-substitutedbenzimidazoles and diphenyl chlorophosphate (ClPO₃Ph₂) in the presence of potassium hydroxide (KOH) under an argon atmosphere. The structures of the phosphoramidates were characterized by NMR, IR, melting point, and elemental analysis.     

Synthesis and polymerization of phosphorus‐containing acrylates

Novel phosphorus‐containing acrylate monomers were synthesized by two different routes. The first involved the reaction of ethyl α‐chloromethyl acrylate and t‐butyl α‐bromomethyl acrylate with diethylphosphonoacetic acid. The monomers were bulk‐ and solution‐polymerized at 56–64 °C with 2,2′‐azobisisobutyronitrile. The ethyl ester monomer showed a high crosslinking tendency under these conditions. The selective hydrolysis of the ethyl ester phosphonic ester compound was carried out with trimethylsilyl bromide, producing a phosphonic acid monomer. In the second route, ethyl α‐hydroxymethyl acrylate and t‐butyl α‐hydroxymethyl acrylate were reacted with diethylchlorophosphate. The bulk homopolymerization and copolymerization of these monomers with methyl methacrylate and 2,2′‐azobisisobutyronitrile gave soluble polymers. The attempted hydrolysis of the monomers was unsuccessful because of the loss of the diethylphosphate group. The relative reactivities of the monomers in the photopolymerizations were also compared. The ethyl α‐hydroxymethyl acrylate/diethylphosphonic acid monomer showed higher reactivity than the other monomers, which may explain the crosslinking during the polymerization of this monomer. The reactivities of other derivatives were similar, but the rates of polymerization were slow in comparison with those of methyl methacrylate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3221–3231, 2002     

Aliphatic-aromatic poly(ether amide)s containing oxyethylene units. Synthesis and characterization

The synthesis and characterization of aromatic polyamides containing oxyethylene units is reported, and the differences observed in polycondensation yields, molecular weights, and molecular weight distributions, as a function of the method of synthesis, are discussed. Four diamines containing oxyethylene units and aromatic rings, meta and para oriented, and their corresponding hydrochlorides were prepared as condensation monomers to be combined with isophthaloyl chloride (IPC) and terephthaloyl chloride (TPC). High molecular weight polyamides were obtained by interfacial and low-temperature solution methods. Values of (OVERLINE)M(/OVERLINE)_n up to 6 × 10⁴ g/mol and (OVERLINE)M(/OVERLINE)_w up to 2 × 10⁵ g/mol could be measured by gel permeation chromatography using aromatic polyamide standards, and values of (OVERLINE)M(/OVERLINE)_n up to 2 × 10⁵ g/mol and (OVERLINE)M(/OVERLINE)_w up to 5 × 10⁵ g/mol by using polystyrene standards. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of low‐band‐gap conjugated polymers containing phenothiazine and benzo‐2,1,3‐thia‐/seleno‐diazole

Two phenothiazine‐based conjugated polymers, poly(3, 7‐divinylene‐N‐octyl‐phenothiazine‐alt‐benzo‐2,1,3‐ thiadiazole) (PQS) and poly(3,7‐divinylene‐N‐octyl‐phenothiazine‐alt‐benzo‐2,1,3‐selenodiazole) (PQSe) were synthesized by Heck coupling reaction. The chemical structures of the two polymers were confirmed by ¹H‐NMR and Ft‐IR. They showed good solubility in some common organic solvents such as tetrahydrofuran (THF), chloroform. The weight‐average molecular weight (Mw) of the polymers determined by GPC in THF against polystyrene standards was 3.7 × 10³ for PQS and 1.9 × 10³ for PQSe, respectively. The temperatures of 5% weight loss (T₅) were 385.0°C for PQS and 324.0°C for PQSe, respectively, determined by TGA measurements under nitrogen ambience. UV–vis absorption spectra of the polymer films showed the absorption maxima at 537 nm for PQS and 539 nm for PQSe, with the full width at half maximum (FWHM) of 190 and 230 nm, respectively. The optical band gaps ( ) of the polymer films are 1.86 eV for PQS and 1.80 eV for PQSe, respectively. As the polymers have low‐band‐gap and broad absorption in the visible region, they may be used as potential light‐harvesting materials for photovoltaic devices (PVDs). Furthermore, photoluminescence (PL) spectra of the polymer solutions showed the emission maxima at 698 nm for PQS and 709 nm for PQSe, with FWHM of 152 nm and 167 nm, respectively, which revealed that these two polymers may be used as red and near infrared light‐emitting materials for polymeric light‐emitting diodes (PLEDs). Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of poly(4‐hydroxystyrene)‐based block copolymers containing acid‐sensitive blocks by living anionic polymerization

Living anionic polymerization of an acetal protected 4‐hydroxystyrene monomer, (4‐(2‐tetrahydropyranyloxy)styrene) (OTHPSt), and the chain extension of the poly(OTHPSt) anion with a variety of monomers including styrene, 4‐tert‐butylstyrene, methacryloyl polyhedral oligomeric silsesquioxane (MAPOSS) and hexamethylcyclotrisiloxane is demonstrated. The P(OTHPSt) homopolymer has a glass transition temperature well above room temperature, which facilitates handling and purification of the protected poly(4‐hydroxystyrene) (PHS). The resulting diblock copolymers have narrow dispersities <1.05. Chemoselective mild deprotection conditions for the P(OTHPSt) block were identified to prevent simultaneous degradation of the MAPOSS or dimethylsiloxane (DMS) block, thus allowing for the first reported synthesis of P(HS‐b‐DMS) and P(HS‐b‐MAPOSS). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1458–1468     

Cyclolinear polysiloxanes. I. Synthesis and characterization

The synthesis and characterization of two novel cyclic siloxanes, diacetoxydiethyltetramethylcyclotetrasiloxane and diacetoxytriethylpentamethylcyclopentasiloxane, and cyclolinear polymers synthesized from these monomers are presented. The cyclic siloxanes were synthesized from tetramethylcyclotetrasiloxane and pentamethylcyclopentasiloxane, respectively, by acetylation followed by ethylation. The cyclic monomers were characterized with ¹H NMR spectroscopy. Subsequently, the cyclic siloxanes were self‐condensed into cyclolinear polysiloxanes and cocondensed (extended) with silanol‐terminated polydimethylsiloxane into high‐molecular‐weight polymers containing cyclic units withlinearpolydimethylsiloxane spacers (extended cyclolinear polysiloxanes). The molecular weights of both the cyclolinear polysiloxanes and extended cyclolinear polysiloxanes were determined. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4039?4052, 2006     

Synthesis and cationic photopolymerization of epoxy‐functional siloxane monomers and oligomers

A series of difunctional silicon‐containing monomers were prepared with a novel method consisting of the monohydrosilation of an α,ω‐difunctional Si? H‐terminated siloxane with a vinyl‐functional epoxide or oxetane followed by the dehydrodimerization of the resulting Si? H‐functional intermediate. This method used simple, readily available starting materials and could be conducted as a streamlined one‐pot, two‐step synthesis. This novel method was also applied to the synthesis of several epoxy–silicone oligomers. The reactivities of these new monomers and oligomers were examined with Fourier transform real‐time infrared spectroscopy and optical pyrometry. Those monomers containing epoxycyclohexyl groups displayed excellent reactivity in cationic ring‐opening polymerization in the presence of lipophilic onium salt photoinitiators. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3056–3073, 2003     

Synthesis and second‐order nonlinear optical properties of multifunctional polysiloxanes with sulfonyl‐based chromophores

Two new polysiloxanes ( P1 and P2 ) with a high density of sulfonyl‐based chromophores were prepared by a new two‐step method. Poly[methyl‐3‐(9‐carbazolyl)propyl siloxane] was partially formulated by the standard Vilsmeier reaction, and formyl groups of high reactivity were condensed with cyanoacetylated chromophores; this yielded polysiloxanes P1 and P2 in almost complete conversions. Their structures were verified with ¹H NMR, IR, and ultraviolet–visible spectra. P1 and P2 exhibited good solubility in common organic solvents and were thermally stable. The maximum absorptions appeared at about 452 and 390 nm for P1 and P2 , respectively, in tetrahydrofuran; they were blueshifted about 42 and 8 nm, respectively, in comparison with those of the corresponding chromophores with a nitro acceptor and resulted in a wider transparency window. The P1 values of the nonlinear optical coefficient (d₃₃), measured by in situ second harmonic generation, was 16.2 pm/V. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1317–1324, 2005     

Synthesis and applications of 2,7‐carbazole‐based conjugated main‐chain copolymers containing electron deficient bithiazole units for organic solar cells

A series of low‐band‐gap (LBG) donor–accepor conjugated main‐chain copolymers ( P1 – P4 ) containing planar 2,7‐carbazole as electron donors and bithiazole units (4,4′‐dihexyl‐2,2′‐bithiazole and 4,4′‐dihexyl‐5,5′‐di(thiophen‐2‐yl)‐2,2′‐bithiazole) as electron acceptors were synthesized and studied for the applications in bulk heterojunction (BHJ) solar cells. The effects of electron deficient bithiazole units on the thermal, optical, electrochemical, and photovoltaic (PV) properties of these LBG copolymers were investigated. Absorption spectra revealed that polymers P1 – P4 exhibited broad absorption bands in UV and visible regions from 300 to 600 nm with optical band gaps in the range of 1.93–1.99 eV, which overlapped with the major region of the solar emission spectrum. Moreover, carbazole‐based polymers P1 – P4 showed low values of the highest occupied molecular orbital (HOMO) levels, which provided good air stability and high open circuit voltages (V_oc) in the PV applications. The BHJ PV devices were fabricated using polymers P1 – P4 as electron donors and (6,6)‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) or (6,6)‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) as electron acceptors in different weight ratios. The PV device bearing an active layer of polymer blend P4:PC₇₁BM (1:1.5 w/w) showed the best power conversion efficiency value of 1.01% with a short circuit current density (J_sc) of 4.83 mA/cm², a fill factor (FF) of 35%, and V_oc = 0.60 V under 100 mW/cm² of AM 1.5 white‐light illumination. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and characterization of alt‐copoly [oligosiloxane/1,4‐bis(ethylenediphenylsilyl)benzene]s

1,4‐Bis(vinyldiphenylsilyl)benzene ( I ) has been prepared and copolymerized by Pt‐catalyzed hydrosilylation with 1,9‐dihydridodecamethylpentasiloxane ( II ), 3,5,7‐tris(3′,3′,3′‐trifluoropropyl)‐1,1,3,5,7,9,9‐heptamethylpentasiloxane ( III ) and two different α,ω‐bis(hydrido)polydimethylsiloxanes (PDMS). The monomers and polymers were fully characterized by IR, UV, ¹H, ¹³C, ¹⁹F, and ²⁹Si‐NMR spectroscopy. The starting PDMS polymers and the product copolymers were further characterized by GPC, DSC, and TGA. The polymers showed thermal transitions characteristic to thermoplastic elastomers. The 1,4‐bis(ethyldiphenylsilyl)benzene moieties displayed melting transitions above room temperature while copolymer glass transition temperatures were below room temperature. Fluorescence spectra and quantum efficiencies of I and copolymers have been determined. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4825–4831, 2006     

New fluorinated thermoplastic elastomers. II. Synthesis and characterization of perfectly alternating fluorinated polyimide–fluorinated polyhybridsiloxane block copolymers via polyhydrosilylation

The synthesis of perfectly alternating fluorinated polyimide–fluorinated polyhybridsiloxane block copolymers (FPI‐FPHSX) was achieved through polyhydrosilylation of α,ω‐diallylfluorinated polyimides (AT‐FPI) and α,ω‐dihydrosilane fluorinated–polyhybridsiloxanes (HT‐FPHSX). A series of three FPI‐FPHSX containing 15, 38, and 56 wt % of polyimide was synthesized and characterized by tuning the number‐average molecular weight either of the hard polyimide segments or of the soft polyhybridsiloxane segments. The influence of the soft and hard segment lengths on the behavior of the thermoplastic elastomer material was studied (hardness, surface tension, thermal stability). The FPI‐FPHSX block copolymers thermomechanical properties are also reported. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 200–207, 2004     

Synthesis and characterization of alkylated N‐vinylformamide monomers and their polymers

N‐alkyl‐N‐vinylformamide monomers (alkyl: n‐butyl, hexyl, decyl, and dodecyl) are synthesized in two steps: first, preparation of N‐vinylformamide potassium salt by the reaction of N‐vinylformamide (NVF) with potassium t‐butoxide, then reaction with alkyl bromide. All four monomers are liquid and are characterized by IR, ¹H NMR, ¹³C NMR, and mass spectra. They exist as rotomers in solution and a 2D NOE experiment on the N‐hexyl containing polymer shows the E isomer to be favored. The polymerizability of the four monomers is from good to fair, depending upon the length of alkyl chain on the N‐atom‐‐the longer the chain length, the lower lower the polymerizability of monomer. The hydrolysis of poly(N‐hexyl‐N‐vinylformamide) and poly(N‐dodecyl‐N‐vinylformamide) under acidic and basic conditions was examined. Studies show that hydrolytic cleavage of formyl groups of poly (N‐alkylated‐N‐vinylformamide) depends on the hydrophobicity of the alkyl substituent on the N‐atom under acidic conditions; both polymers were hydrolyzed to only a minor extent under alkaline conditions. The N‐alkylated monomers can copolymerize with NVF and demonstrate amphiphilic properties. The copolymers demonstrate a critical aggregation concentration above which they can solubilize a water insoluble dye; the N‐hexyl containing copolymer stabilizes a castor oil‐in‐water emulsion. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4994–5004, 2004     

Synthesis and characterization of novel fluorosilicone rubber using imide modified vinyl‐containing fluorosilicone resin as cross‐linker

A novel imide modified vinyl‐containing fluorosilicone resin (MP‐VFS) was firstly prepared from maleopimaric acid (MPA), and characterized by ¹H NMR and ¹³C NMR. Containing MPA based imide heterocycle (MPABI), MP‐VFS was further used as a novel cross‐linker to prepare MPA modified fluorosilicone rubber (MP‐FSR). Morphology, mechanical and oil‐resistance properties, thermal properties, and low temperature resistance of MP‐FSR had been studied. Microphase separation was observed in MP‐FSR. Although the tensile strength of fluorosilicone rubber was not significantly enhanced, the tearing strength, breaking elongation, rebound resilience and hardness were effectively improved. When the MP‐VFS content was 2.0 wt %, the tearing strength of MP‐FSR was increased by 23.5%, breaking elongation by 18.6% and rebound resilience by 9.7%. The thermal stability was enhanced due to the incorporation of MPABI. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1769–1776     

Directed In Situ Shaping of Complex Nano‐ and Microstructures during Chemical Synthesis

Chemical composition and shape determine the basic properties of any object. Commonly, chemical synthesis and shaping follow each other in a sequence, although their combination into a single process would be an elegant simplification. Here, a pathway of simultaneous synthesis and shaping as applied to polysiloxanes on the micro‐ and nanoscale is presented. Complex structures such as stars, chalices, helices, volcanoes, rods, or combinations thereof are obtained. Varying the shape‐controlling reaction parameters including temperature, water saturation, and the type of substrate allows to direct the reaction toward specific structures. A general mechanism of growth is suggested and analytical evidence and thermodynamic calculations to support it are provided. An aqueous droplet in either gaseous atmosphere or in a liquid organic solvent serves as a spatially confined polymerization volume. By substituting the starting materials, germanium‐based nanostructures are also obtained. This transferability marks this approach as a major step toward a generally applicable method of chemical synthesis including in situ shaping.