Polymeric organosilicon system VIII. Synthesis of poly[(disilanylene)diethynylene] with highly conducting properties

The reaction of bis(trimethylsilyl)butadiyne with 2 equiv. of methyllithium, followed by 1,2-dichloro-1,2-dimethyldiphenyl- or 1,2-dichloro-1,2-diethyldimethyldisilane gives poly[(1,2-dimethyldiphenyldisilanylene)diethynylene] (II) or poly[(1,2- diethyldimethyldisilanylene)diethynylene] (III), respectively. Films of II and III become conducting when treated with SbF₅ vapor.     

Novel conducting polymer poly[bis(phenylamino)disulfide]: Synthesis,characterization, and properties

A bis(phenylamino)disulfide was prepared through the reaction of S₂Cl₂ with aniline, and its configuration was confirmed with elemental analysis, Fourier transform infrared (FTIR), Fourier transform Raman (FT‐Raman), and ¹H NMR spectroscopy. A novel conducting polymer, poly[bis(phenylamino)disulfide] (PPAD), was synthesized from bis(phenylamino)disulfide by both chemical and electrochemical polymerization. The structure of this polymer, in which the side‐chain disulfide bonds were linked to the nitrogen atoms of the main‐chain polyaniline, was characterized with FTIR, FT‐Raman, gel permeation chromatography, electron spectroscopy, and X‐ray photoelectron spectroscopy. A four‐probe measurement revealed that the electrical conductivity of PPAD was 1.8 × 10^?2 to 2.1 × 10^?3 S cm^?1, depending on the doping agents and the pH of the medium for either chemical synthesis or electrochemical synthesis. The conductivity, molecular weight, and spectroscopic properties of the polymer, in comparison with those of polyaniline, showed decreases in the polaron delocalization, structural order, and doping level of the main chain because of the steric hindrance of side‐chain S? S bonds. The cyclic voltammograms of the polymer and the monomer showed that the redox reactions (doping/undoping processes) of the main chain (π‐conjugated system) occurred in almost the same potential range of ?0.3 to 0.3 V versus an Ag/AgCl (saturated KCl) electrode as that of thiol (thiolate anion)/disulfide of the side chain in PPAD; the bond cleavage (reduction) and formation (oxidation) reactions of the disulfide bond in the polymer became easier and more reversible than those of the monomer. These results suggested that this conducting organodisulfide polymer might be a candidate material for energy‐storage devices such as lithium secondary batteries, proton‐exchange batteries, and electrochemical capacitors. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2329–2339, 2004     

Crystallization and melting of cold-crystallized poly(phenylene sulfide)

In this study, we report the melting behavior of poly(phenylene sulfide), PPS, which has been cold-crystallized from the rubbery amorphous state. We find that the crystallization kinetics are faster for cold-crystallized PPS than for melt-crystallized material, due to formation during quenching of a short-range ordered, but noncrystalline, structure. We observe that the endothermic response of cold-crystallized PPS at a large undercooling consists of a low temperature endotherm, followed by an exothermic region, and by the main higher melting endotherm. The lower melting peak temperature of cold-crystallized PPS increases as the crystallization temperature increases, but the main upper melting peak temperature remains almost the same. The size of the exothermic region is strongly related to the degree of undercooling, and must be taken into account in order properly to determine the degree of crystallinity of the material prior to the scan. When the crystallization time is varied, we see a systematic decrease in the size of the main endotherm, and an increase in size of the lower melting endotherm. This suggests that a portion of the main endothermic response is due to reorganization during the scan. Annealing will not only increase the degree of crystallinity but also improve the crystal perfection; therefore the ability of an annealed sample to reorganize decreases as the annealing time increases. However, an additional third melting peak is seen when a cold-crystallized sample is annealed at high temperature for a sufficiently long residence time. The existence of the third melting peak suggests that more than one kind of distribution of crystal perfection may occur when PPS has been cold-crystallized and subsequently annealed.     

Synthesis of amphiphilic poly(para‐phenylene)s by Suzuki polycondensation

1,4‐Dibromobenzenes carrying nonpolar hexoxy and polar oligo(ethylene glycol) side chains were subjected to Suzuki polycondensation with a benzene‐1,4‐bisboronic acid ester to produce high‐molar‐mass poly(para‐phenylene)s. The molar masses were determined with size exclusion chromatography with conventional polystyrene and universal calibration. These novel amphiphilically equipped rigid‐rod polymers have the potential to segregate lengthwise into polar and nonpolar domains, a property that has only rarely been described, and promise to exhibit novel interesting supramolecular properties. The oligo(ethylene gylcol) side chains terminate with a silyl‐protected alcohol group, and its deprotection on the polymer was proven to proceed quantitatively. This not only led to a further polarity increase but allows us to attach even more polar (e.g., charged) units in future projects. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2879–2889, 2003     

聚苯醚磺酸锂与聚醋酸乙烯酯共混物的导电性能研究

为改善聚苯醚磺酸锂（SPPOLi）的导电性能，将聚酷酸乙烯酯（PVAc）与之共混，X-射线衍射分析表明，PVAc可降低SPPOLi凝聚结构的有序程度；发现共混后电导率有了较大提高，共混物的电导对温度的依赖关系不符合阿仑尼马斯方程；同时，共混物仍保持了单离子传导性．     

Synthesis and conformation of poly(L-azetidine-2-carboxylic acid-L-proline) and poly([L-proline]3-L-azetidine-2-carboxylic acid)

The synthesis, characterization, and conformational assessment of poL y(L -Aze-L -Pro) and poly[(L -Pro)₃-L -Aze] are reported. The polymers were prepared by using the pentachlorophenol active ester as the polymerizable tetrapeptide derivatives. The copolymer, poly(L -Aze-L -Pro), assumes a Form II helix in polar solvents, and is converted into a form I-like helix at a critical solvent composition of ethanol to trifluoroethanol. The CD spectrum of this Form I-like conformation of poly(L -Aze-L -Pro) is similar to that of poly(trans-5-isopropyl-L -proline), indicating that the rigid four-membered ring at the alternating position can lock in the structure by a mechanism similar to that of a bulky substituent at the trans-5-position of proline. The helix conformation of this copolymer was unfolded in a 0.2M CaCl₂ aqueous solution. In contrast to poly(L -Aze-L -Pro), the copolymer of poly[(L -Pro)₃-L -Aze] contains both cis and trans peptide bond geometry when dissolved in a 90:10 ETOH-H₂O mixture. The conversion of the mixed conformation of poly[(L -Pro)₃-L -Aze)] into a polyproline Form II-like structure occurred in highly polar solvent environments such as water.     

Synthesis and electronic properties of poly (E,E)-[6.2]-(2,5) thiophenophane-1,5-diene)

Cationic cyclopolymerization of (E, E)-[6.2]-(2,5) thiophenophane-1,5-diene ( 2 ) gave polymer 3 which has bridged thiophene rings pendant to the polymer backbone. The structural, thermal, and electronic properties of polymer 3 were compared to those of its benzene analogue ( 1 ) and its nonbridged analogue poly (2-vinylthiophene) ( 5 ). The onsets of thermal degradation for polymers 3 and 5 under helium were 425 and 382°C, respectively. Polymer 3 exhibited conductivity in the 10^?3?10^?4 S/cm range when exposed to iodine vapor, four orders of magnitude higher than for 5 treated in the same manner. Apparent energies of activation for conductivity in iodine saturated polymers 3 (0.57 eV) and 5 (0.61 eV) were calculated from conductivity temperature dependence measurements. Conductivity parameters for iodine saturated 3 show both a higher level of conductivity and weaker temperature dependence than for the corresponding cyclopolymer 1 which has benzene rather than thiophene moieties, suggesting that greater charge generation occurs in 3 , due to the lower oxidation potential of the thiophenophane repeat units. Differences in conductivity behavior for iodine saturated polymers 1, 3 , and 5 are discussed in terms of both charge generation and mobility. © 1994 John Wiley & Sons, Inc.     

Preparation,characterization and thermal stability of poly[2-(Dimethylamino)ethyl acrylate]

Poly[2-(dimethylamino)ethyl acrylate] (PDAEA) and polymer complexes of 2-(dimethylamino)ethyl acrylate (DAEA) with nickel(II), copper(II), iron(III) and cobalt(II) chlorides were prepared and characterized by means of IR, electronic spectra and elemental analysis. The thermal stability of the homopolymer was compared with those of the polymer complexes, and the order of stability was given. The activation energies of the polymer complexes were calculated.     

Phase structure and mechanical properties of modified poly(phenylene oxide) with high fluidity

Polyphenylene oxide (PPO) possesses excellent mechanical properties and heat resistance but extremely high viscosity. Virgin PPO has to be blended with polystyrene (PS) to reduce the viscosity. However, PS is miscible with PPO; it reduces not only the viscosity but also the heat distortion temperature and, consequently, narrows the applications. This paper is an attempt to develop crystalline additives that will dissolve in PPO at processing temperature but precipitate and recrystallize after molding. Thereby, the additives are able to reduce the viscosity of PPO melts but will not reduce the heat distortion temperature of PPO materials. In the present work, a PPO was compounded with bisphenol‐A and bisphenol‐S as well as PS separately on Haake Rheometer and the mixing torque was recorded. The dynamic properties of the modified PPO were analyzed with DMA and the mechanical properties were tested at ambient and elevated temperatures. The phase structures were examined with DSC and TEM. The effect of the additives on the fluidity, mechanical properties, and heat distortion temperature of the PPO compounds was investigated. All three additives dissolved in the PPO during mixing and reduced the mixing torque. But bisphenol‐S precipitated after molding and is present as 40 nm crystalline phases in the molded materials; it did not affect the glass transition nor did it deteriorate the performance at elevated temperature. While bisphenol‐A did not recrystallize after molding; it reduced the T_g and heat distortion temperature as does PS. General principles about such plasticizers with phase transition for PPO were proposed. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis of soluble poly(para‐phenylene) with a long polymer chain: Characteristics of regioregular poly(1,4‐phenylene)

Soluble poly(para‐phenylene) having a long polymer chain (more than six repeat units) was synthesized with a tert‐butyl end‐group (t‐PPP) and was found to have improved solubility and excellent optical properties. Poly(1,3‐cyclohexadiene) (PCHD) consisting of only 1,4‐cyclohexadiene (1,4‐CHD) units was synthesized with a tert‐butyl end‐group (t‐PCHD), and completely dehydrogenated to obtain t‐PPP. This end‐group effectively prevented the crystallization of t‐PPP, and polymers containing up to 16 repeat units were soluble in tetrahydrofuran. Soluble t‐PPP obtained had an ability to form a tough thin film prepared by spin‐coating method. Optical analyses of t‐PPP provided strong evidence for a linear polymer chain structure. A block copolymer of t‐PPP and a soluble polyphenylene (PPH) was then synthesized, and the excellent optical properties were retained by this block copolymer along with its solubility. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5223–5231, 2008     

Comparative study of the optical,electrochemical, electrolumiscent,and photovoltaic properties of dendritic pendants modified poly(p‐phenylene vinylene)s

In this study, the optical, electrochemical, electrolumiscent, and photovoltaic properties of a series of poly(p‐phenylene vinylene) (PPV) derivatives bearing different dendritic pendants, poly{2‐[3′,5′‐bis(2″‐ethylhexyloxy)benzyloxy]‐1,4‐phenylenevinylene} (BE‐PPV), poly{2‐[2′,5′‐bis(3″,7″‐dimethyl)octyloxy]‐1,4‐phenylenevinylene} (BD‐PPV), poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV), poly{2‐[3′,5′‐bis(2″‐ethylhexyloxy)benzyloxy]‐1,4‐phenylenevinylene}‐co‐poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene] (BE‐co‐MEH‐PPV), and poly{2‐[2′,5′‐bis(3″,7″‐dimethyl)octyloxy]‐1,4‐phenylenevinylene}‐co‐poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylenevinylene] (BD‐co‐MDMO‐PPV), were investigated. The steric pendants strongly affect the absorption spectra, photoluminescence (PL) sepctra, the onset oxidation/reduction potentials, and further affect the electrolumiscent and photovoltaic properties. Copolymerization can reduce the steric effect and improve the electrolumiscent and photovoltaic properties. The brightness of light‐emitting diodes base on copolymer BE‐co‐MEH‐PPV and BD‐co‐MDMO‐PPV reached 3988 and 3864 cd/m², respectively, much higher than that based on homopolymer BE‐PPV (523 cd/m²) and BD‐PPV (333 cd/m²), also higher than that based on MEH‐PPV (3788 cd/m²). The power conversion efficiency (PCE) of solar cells based on BE‐co‐MEH‐PPV and BD‐co‐MDMO‐PPV reached 1.41, 0.76%, respectively, much higher than that based on BE‐PPV (0.24%) and BD‐PPV (0.14%). Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis and fractionation of poly(phenylene methylene)

Poly(phenylene methylene) (PPM) was isolated in a broad range of molar masses by optimization of the catalytic polymerization of benzyl chloride with SnCl₄ or FeCl₃, followed by fractionation by Soxhlet extraction or phase separation in concentrated solutions in poor solvents. Low molar mass products were also obtained by quenching the reaction at moderate monomer conversions. Products with number average molar masses (M_n) ranging from 200 to 61,000 g mol⁻¹ were isolated, the latter being an order of magnitude above the previously reported values. DSC analysis of polymers of different molar masses revealed that the glass transition temperature follows the Flory‐Fox equation reaching a plateau value of 65 °C at a molar mass between 10,000 and 20,000 g mol⁻¹. The onset of decomposition temperature of higher molar mass products proceeds above 450 °C (maximum decomposition rate at 515 °C), according to TGA. Furthermore, the substitution pattern of PPM was discussed by study of chemical shifts of the methylene group by extensive NMR spectroscopy (¹H, ¹³C, DEPT, and HSQC) and by comparison with two mono‐substituted derivatives of PPM—poly(2,4,6‐trimethylphenylene methylene) and poly(2,3,5,6‐tetramethylphenylene methylene)—which were synthesized analogous to PPM. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 309–318     

Synthesis and properties of poly(hydroxyurethane)s

Bis(cyclic Carbonate)s 1 were prepared by the reaction of bis(epoxide)s and atmospheric pressure of CO₂ in the presence of sodium iodide and triphenylphosphine as catalysts at 100°C in high yield. Polyaddition of 1 and hexamethylenediamine ( 2a ) or dodecamethylenediamine ( 2b ) in dimethylsulfoxide or N,N-dimethylacetamide (DMAc) at 70 or 100°C for 24 h afforded corresponding poly(hydroxyurethane)s with M?_n 20,000–30,000. When ethylenediamine ( 2c ) or 1,3-propanediamine ( 2d ) was used as a diamine, poly(hydroxyurethane)s with lower molecular weight were obtained. The presence of water, methanol, or ethyl acetate in the solvent had little effect on the M?_n of the polymer obtained, because of the high chemoselectivity of the reaction of the five-membered cyclic carbonate and amine. Polyaddition of bis(cyclic carbonate) bearing ester groups and 2a also afforded the corresponding poly(hydroxyurethane) without aminolysis of the ester groups. Poly(hydroxyurethane) 3 obtained from the bis(cyclic carbonate) derived from bisphenol A was less soluble in organic solvents than model polyurethane 8 having no hydroxy groups obtained from 4,4′-isopropylidenebis(2-hydroxyethoxybenzene) and hexamethylene diisocyanate, and was thermally stable as well as 8.3 easily undertook crosslinking at room temperature by the treatment with hexamethylene diisocyanate or aluminium triisopropoxide in DMAc or tetrahydrofuran. The gel crosslinked by aluminium triisopropoxide regenerated the original polymer at room temperature by treatment with 1.5 equiv of 1.2M HCl in N-methylpyrollidinone for 1 h. © 1993 John Wiley & Sons, Inc.     

Water‐soluble poly(ethylene oxide)‐block‐poly(p‐phenylene vinylene) copolymer: Synthesis and characterization

Water‐soluble and photoluminescent block copolymers [poly(ethylene oxide)‐block‐poly(p‐phenylene vinylene) (PEO‐b‐PPV)] were synthesized, in two steps, by the addition of α‐halo‐α′‐alkylsulfinyl‐p‐xylene from activated poly(ethylene oxide) (PEO) chains in tetrahydrofuran at 25 °C. This copolymerization, which was derived from the Vanderzande poly(p‐phenylene vinylene) (PPV) synthesis, led to partly converted PEO‐b‐PPV block copolymers mixed with unreacted PEO chains. The yield, length, and composition of these added sequences depended on the experimental conditions, namely, the order of reagent addition, the nature of the monomers, and the addition of an extra base. The addition of lithium tert‐butoxide increased the length of the PPV precursor sequence and reduced spontaneous conversion. The conversion into PPV could be achieved in a second step by a thermal treatment. A spectral analysis of the reactive medium and the composition of the resulting polymers revealed new evidence for an anionic mechanism of the copolymerization process under our experimental conditions. Moreover, the photoluminescence yields were strongly dependant on the conjugation length and on the solvent, with a maximum (70%) in tetrahydrofuran and a minimum (<1%) in water. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4337–4350, 2005     

Synthesis and characterization of new poly[phenylquinoxaline(ether)imides]

A series of new aromatic poly[phenylquinoxaline(ether)imides] were synthesized by solution polycondensation of aromatic diamines containing preformed phenylquinoxaline groups with dianhydrides having ether linkages and isopropylidene or hexafluoroisopropylidene units. All polymers are readily soluble in polar organic solvents (N-methylpyrrolidinone, DMF, dimethylacetamide) and in less polar liquids such as chloroform. Very thin coatings were deposited onto silicon wafers. According to atomic force microscopy, they had a smooth, pinhole-free surface. The polymers showed high thermal stability with decomposition temperatures above 470 °C and glass transition temperatures in the range of 210–238 °C, being thus characterized by a large gap between the glass transition and decomposition temperatures.Based on the report presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry dedicated to the 50th year anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences (Moscow, May 30–June 4, 2004).Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1952–1957, September, 2004.     

Synthesis and properties of poly[arylene ether (N-arylenebenzimidazole)]s

Poly(arylene ether)s containing N-arylenebenzimidazole groups were prepared by the aromatic nucleophilic displacement reaction of two new bis(hydroxyphenyl-N-arylenebenzimidazole)s with activated aromatic difluorides in sulfolane at 200°C in the presence of anhydrous potassium carbonate. The bis(hydroxyphenyl-N-arylenebenzimidazole)s were prepared from bis(o-aminoanilino) arylenes and phenyl-4-hydroxybenzoate. The polymers were soluble in N-methyl-2-pyrrolidinone and m-cresol and exhibited inherent viscosities from 0.37–0.86 dL/g and glass transition temperatures from 219–289°C. Thermogravimetric analyses showed 5% weight losses from 463–506°C in air and 467–522°C in nitrogen. Unoriented thin films exhibited tensile strengths, moduli, and break elongations at 23°C of 10.2–12.5 ksi, 318–365 ksi, and 4–7%, respectively, and at 177°C of 5.1–6.9 ksi, 256–296 ksi, and 1–5%, respectively. A 50 : 50 random copolymer prepared from 1,3-bis(4-fluorobenzoyl) benzene, 1,1'-(4,4'-biphenylene)-bis[2-(4-hydroxyphenyl)benzimidazole], and 5,5'-bis[2-(4-hydroxyphenyl)benzimidazole] exhibited higher moisture absorption and lower tensile properties than those predicted by a rule of mixtures relationship. The chemical, physical, and mechanical properties of these polymers are discussed. © 1993 John Wiley & Sons, Inc.?     

Synthesis of poly(m‐phenylene) and poly(m‐phenylene)‐block‐ poly(3‐hexylthiophene) with low polydispersities

Well‐defined poly(m‐phenylene) (PMP), which is poly(1,3‐dibutoxy‐m‐phenylene), was successfully synthesized via Grignard metathesis polymerization. PMP with a reasonably high number‐average molecular weight (M_n) of 25,900 and a very low polydispersity index of 1.07 was obtained. The polymerization of a Grignard reagent monomer, 1‐bromo‐2,4‐dibutoxy‐5‐chloromagnesiobenzene, proceeded in a chain‐growth manner, probably due to the meta‐substituted design producing a short distance between the MgCl and Br groups and thereby making a smooth nickel species (? C? Ni? C? ) transfer to the intramolecular chain end (? C? Ni? Br) over a benzene ring. PMP showed a good solubility in the common organic solvents, such as tetrahydrofuran, CH₂Cl₂, and CHCl₃. Furthermore, a new block copolymer comprised of PMP and poly(3‐hexylthiophene) was also prepared. The tapping mode atomic force microscopy image of the surface of the block copolymer thin film on a mica substrate showed a nanofibril morphology with a clear contrast. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Dielectric relaxation of poly(phenylene sulfide) containing a fraction of rigid amorphous phase

The dielectric relaxation behavior of poly(phenylene sulfide), PPS, has been investigated from room temperature to 180°C. This study was undertaken to examine the mobility of the amorphous phase through the glass transition region, to determine the contribution that rigid amorphous phase material makes to the relaxation process. Semicrystalline samples contain a fraction of the rigid amorphous phase, which was determined from the heat capacity increment at the glass transition, using degree of crystallinity determined from x-ray scattering. In the dielectric experiment, we measured the temperature and frequency dependence of the real and imaginary parts of the dielectric function. ε″ vs. ε′ was used to determine the dielectric relaxation intensity, δε = ε_s–ε∞, at temperatures above the glass transition. For amorphous PPS, δε decreases as temperature increases, while for all semicrystalline PPS, δε increases with temperature. The ratio of semicrystalline intensity to amorphous intensity determines the total fraction of dipoles which are already relaxed at a given temperature. Results indicate that more and more rigid amorphous phase material relaxes as the temperature is increased. This provides the first evidence that rigid amorphous phase material in PPS contains chains that possess different levels of molecular mobility. Finally, to the temperature of the loss peak maximum, at a given frequency, we assign the value of the dielectric T_g. For both melt and cold crystallization, the dielectric T_g systematically decreases as the crystallization temperature increases, and as the fraction of rigid amorphous phase decreases.     

Homoconjugation in poly(phenylene methylene)s: A case study of non‐π‐conjugated polymers with unexpected fluorescent properties

Poly(phenylene methylene) (PPM) exhibits pronounced blue fluorescence in solutions as well as in the solid state despite its non‐π‐conjugated nature. Optical spectroscopy was used to explore the characteristics and the physical origin of its unexpected optical properties, namely absorption in the 350–450 nm and photoluminescence in the 400–600 nm spectral regions. It is shown that PPM possesses two discrete optically active species, and a relatively long photoluminescence lifetime (>8 ns) in the solid‐state. Given the evidence reported herein, π‐stacking and aggregation/crystallization, as well as the formation of anthracene‐related impurities, are excluded as the probable origins of the optical properties. Instead there is sufficient evidence that PPM supports homoconjugation, that is: π‐orbital overlap across adjacent repeat units enabled by particular chain conformation(s), which is confirmed by DFT calculations. Furthermore, poly(2‐methylphenylene methylene) and poly(2,4,6‐trimethylphenylene methylene) – two derivatives of PPM – were synthesized and found to exhibit comparable spectroscopic properties, confirming the generality of the findings reported for PPM. Cyclic voltammetry measurements revealed the HOMO–LUMO gap to be 3.2–3.3 eV for all three polymers. This study illustrates a new approach to the design of light‐emitting polymers possessing hitherto unknown optical properties. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 707–720