Poly(phenylsilsesquioxane)s: Structural and morphological characterization

Poly(phenylsilsesquioxane) (PPSQ) polymers that were obtained from different synthetic routes were comparatively studied. The polymers were characterized by infrared and solid‐state ²⁹Si NMR spectroscopies. According to the results of X‐ray diffraction and thermogravimetric analyses, the materials richest in silanol showed a less organized network and lower weight loss temperature. The morphology of the products was influenced by the preparation conditions. PPSQ, with a morphology rich in spherical particles, was achieved with an n‐hexadecyltrimethylammonium bromide template in the reaction medium, whereas the morphology of this polymer obtained in the absence of the template was featureless. Small‐angle X‐ray scattering analyses revealed that the PPSQ samples showed a predominance of surface‐fractal behavior. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1580–1589, 2000     

Preparation of poly(phenylsilsesquioxane) (PPSQ) particles with ladder structure and the thermal stability of PP/PPSQ composites

The poly(phenylsilsesquioxane) (PPSQ) particles were prepared with both basic and acidic catalyzed processes and the PP/PPSQ composites were prepared by melt blending method. Studies on PPSQ by Infrared (IR), X‐ray diffraction (XRD), ²⁹Si cross polarized (CP) nuclear magnetic resonance (NMR) spectroscopy showed that the structure of PPSQ was ladder structure. The results of scanning electron microscopy (SEM) confirmed that the prepared PPSQ particles were about 2 µm with narrow size distributions. The morphology and thermal stability of PP/PPSQ composites were characterized by SEM, XRD, and thermogravimetric analysis (TGA). The SEM result showed that the particles were well dispersed in the PP matrix and the XRD revealed that the addition of PPSQ influences the crystallinity and crystal orientation of PP. The thermogravimetric analysis results of the PP/PPSQ composites indicated that the incorporation of PPSQ can improve the thermal stability of PP. The Flynn–Wall–Ozawa method was employed to analyze the TGA data and the kinetic results showed that the apparent activation energy for PP/PPSQ composites was much higher than that of neat PP, suggesting that the PPSQ influences the mechanisms of pyrolysis of PP. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of novel bis- and poly(aryldiazenylthiazoles)

A novel series of bis- and poly(arydiazenyl)thiazoles were prepared in good yields by the reaction of the appropriate α-keto-hydrazonoyl chlorides with the corresponding bis- and poly(hydrazinecarbothioamide) in refluxing EtOH/DMF in the presence of few drops of TEA. Based on elemental analyses as well as spectral data, the structures of the new compounds were confirmed.     

Synthesis and characterization of aromatic poly(ether sulfone imide)s derived from sulfonyl bis(ether anhydride)s and aromatic diamines

Two sulfonyl group-containing bis(ether anhydride)s, 4,4′-[sulfonylbis(1,4-phenylene)dioxy]diphthalic anhydride ( IV ) and 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenylene)dioxy]diphthalic anhydride (Me- IV ), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of the bisphenolate ions of 4,4′-sulfonyldiphenol and 4,4′-sulfonylbis(2,6-dimethylphenol) with 4-nitrophthalonitrile in N,N-dimethylformamide (DMF). High-molar-mass aromatic poly(ether sulfone imide)s were synthesized via a conventional two-stage procedure from the bis(ether anhydride)s and various aromatic diamines. The inherent viscosities of the intermediate poly(ether sulfone amic acid)s were in the ranges of 0.30–0.47 dL/g for those from IV and 0.64–1.34 dL/g for those from Me- IV. After thermal imidization, the resulting two series of poly(ether sulfone imide)s had inherent viscosities of 0.25–0.49 and 0.39–1.19 dL/g, respectively. Most of the polyimides showed distinct glass transitions on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (T_g) were recorded between 223–253 and 252–288°C, respectively. The results of thermogravimetry (TG) revealed that all the poly(ether sulfone imide)s showed no significant weight loss before 400°C. The methyl-substituted polymers showed higher T_g's but lower initial decomposition temperatures and less solubility compared to the corresponding unsubstituted polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1649–1656, 1998     

端羟基聚环氧环己烷的合成

端羟基聚环氧环己烷的合成;端羟基聚环氧环己烷;环氧环己烷;阳离子聚合     

Polysilsesquioxane containing tributylstannyl groups as intermediary derivative for organofunctionalization

Poly(phenylsilsesquioxane) containing tributylstannyl groups (TBPSQ) was a useful intermediate for the synthesis of organofunctionalized polysilsesquioxane ( 2 ). The reaction of TBPSQ and monochlorosilane ( 1 ), which possessed an organofunctional group, proceeded under mild and neutral conditions to give 2 with the elimination of tributylstannylchloride. The combined use of the different chlorosilanes 1 enabled the ready preparation of multifunctionalized polysilsesquioxanes 2 . The number‐average molecular weights and dispersions of 2 were almost the same as those of starting TBPSQ. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 286–292, 2002     

Synthesis of poly(silyl ether)s containing pendant chloromethyl groups by the polyaddition of bis(oxetane)s with dichlorosilanes

The polyaddition of bis(3‐ethyl‐3‐oxetanylmethyl) terephthalate (BEOT) with dichlorodiphenylsilane (CPS) using tetrabutylammonium bromide (TBAB) as a catalyst proceeded under mild reaction conditions to afford a polymer containing silicon atoms in the polymer main chain. A poly(silyl ether) (P‐1) with a high molecular weight (M_n = 53,200) was obtained by the reaction of BEOT with CPS in the presence of 5 mol % of TBAB in toluene at 0 °C for 1 h and then at 50 °C for 24 h. The structure of the resulting polymer was confirmed by IR and ¹H NMR spectra. Furthermore, it was proved that the polyaddition of certain bis(oxetane)s with dichlorosilanes proceeds smoothly to give corresponding poly(silyl ether)s with TBAB as the catalyst. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2254–2259, 2000     

Synthesis of high molecular weight poly(ether ketone)s by polycondensation of activated bis(aryl chloride)s with bisphenolates

The ability to achieve high molecular weight poly(ether ketone)s from the polycondensation of bis(aryl chloride)s with bis(phenolate)s has been consistently demonstrated. The polymerizations presented here help to delineate for specific bis(aryl chloride)/bisphenolate pairs the reaction conditions required to obtain high molecular weight polymers. Polycondensation of 1,3-bis(4-chlorobenzoyl)-5-tert-butylbenzene ( 6 ) and 2,2′-bis(4-chlorobenzoyl)-biphenyl ( 15 ) with various bisphenolates as well as of 2,2′-bis(4-hydroxyphenoxy)biphenyl ( 33 ) with 4,4′-dichlorobenzophenone ( 41 ) and 1,3-bis(4-chlorobenzoyl)benzene ( 43 ) were used as representative model systems to select reaction conditions that led to high molecular weight polymers. © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of poly(butylene terephthalates) modified by hydroquinone bis(2-hydroxyethyl)ether

A series of thermoplastic poly(butylene-co-hydroquinone bis(2-hydroxyethyl)ether terephthalates) (PBHT), with different molar ratios of hydroquinone bis(2-hydroxyethyl)ether (HQEE)/1,4-butanediol 9/91, 18/82 and 27/73, were synthesized via melt polycondensation. The compositions, thermodynamics and crystallization properties of the obtained copolyesters were characterized in detail by ¹H NMR, differential scanning calorimeters (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). These results showed that the PBHTs were successfully synthesized, and the incorporation of the HQEE group significantly improved thermal properties of the polymers. However, HQEE did not change the crystal structure of PBT. The T_m values of the copolymers decreased (from 208?°C to 174?°C) with increasing content of HQEE segments, on the contrary, T_g values increased (from 37?°C to 43?°C). The temperatures for 5% weight loss did not decrease and appeared at a range of 373–377?°C.     

Effects of the conductivity of sulfonated poly(phenylene oxide) lithium by the complexation of poly(ethylene oxide)

In the present paper, the structure and conductivity for the complex of sulfonated poly(phenylene oxide) lithium (SPPOLi) and poly(ethylene oxide) (PEG) were studied. Glass transition temperature change determined by differential scanning calorimeter analysis desmonstrated that the two components had some compatibility. X-ray diffraction showed that PEG could decrease the regularity of SPPOLi to some extent. The compatibility and PEG's effect on the regularity may be due to the interaction between the lithium ions of SPPOLi and the oxygen atoms of PEG. Under polarization by electric field, the bands between lithium ions and sulfonation groups relaxed. Meanwhile, the complexation of oxygen atoms could enhance the dissociation of the polymeric lithium salts. Then lithium ions were transported in the process of alternate complexing and decomplexing. The action between lithium ions and oxygen atoms could explain the improvement on the conductivity of SPPOLi.     

Helix formation by poly{bis(hydroxyethyl)-L-glutamine}

Circular dichroism spectra are reported for poly {bis(hydroxyethyl)-L-glutamine}. Its conformation is predominantly that of a statistical coil at or above ambient temperature in water. It becomes partially helical upon cooling. The helix-forming potential of this polypeptide in water is between that of poly(hydroxyethyl-L-glutamine) and poly(hydroxypropyl-L-glutamine). The polypeptide has a large helix content when the solvent is rich in trifluoroethanol.     

On the morphological behavior of ABC miktoarm stars containing poly(cis 1,4-isoprene), poly(styrene), and poly(2-vinylpyridine)

Fundamental understanding of microphase separation in ABC miktoarm copolymers is vital to access a plethora of nonconventional morphologies. Miktoarm stars based on poly(cis 1,4-isoprene) (I), poly(styrene) (S), and poly(2-vinylpyridine) (V) are model systems, which allow systematic studies of the effects of composition, chemical microstructure, and temperature on the thermodynamics of microphase separation. Eleven ISV-x (I:S:V = 1:1:x, v:v:v) miktoarm copolymers were synthesized by anionic polymerization affording well-defined copolymers with a variable V arm. Equilibrium bulk morphologies of all samples, as evidenced by small-angle X-ray scattering, transmission electron microscopy (TEM), and self-consistent field theory, showed a systematic transition from lamellae (x ≈ 0–0.2) to [8.8.4] tiling (x ≈ 0.6–0.9) to cylinders in undulating lamellae (x ≈ 2–4) and, finally, to hexagonally packed core–shell cylinders (x ≈ 5–8). Chemical microstructure of the I arm [poly(cis 1,4-isoprene)] versus poly(3,4-isoprene) is shown to play important role in affecting morphological behavior. To reconcile differences between ISV-x star morphologies reported in the literature and those reported herein, even for the same composition, effects of the microstructure of I arm on the Flory–Huggins parameter between I and V arms were taken into account in a qualitative manner. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1491–1504     

Synthesis and characterization of poly(ethylene glycol) methyl ether endcapped poly(ethylene terephthalate)

Linear and branched poly(ethylene terephthalate) (PET) copolymers with polyethylene glycol) (PEG) methyl ether (700 or 2000 g/mol) end groups were synthesized using conventional melt polymerization. DSC analysis demonstrated that low levels of PEG end groups accelerated PET crystallization. The incorporated PEG end groups also decreased the crystallization temperature of PET dramatically, and copolymers with a high content of PEG (>17.6 wt%) were able to crystallize at room temperature. Rheological analysis demonstrated that the presence of PEG end groups effectively decreased the melt viscosities and facilitated melt processing. XPS and ATR-FTIR revealed that the PEG end groups tended to aggregate on the surface, and the surface of compression molded films containing 34.0 wt% PEG were PEG rich (85 wt% PEG). PEG end-capped PET (34.0 wt% PEG) and PET films were immersed into a fibrinogen solution (0.7 mg/mL BSA) for 72 h to investigate the propensity for protein adhesion. XPS demonstrated that the concentration of nitrogen (1.05%) on the surface of PEG endcapped PET film was statistically lower than PET (7.67%). SEM analysis was consistent with XPS results, and revealed the presence of adsorbed protein on the surface of PET films.     

Synthesis and characterization of side-chain liquid-crystalline poly(ether ester)s having p-substituted biphenyl mesogenic side groups

Several novel mesogenic spiro-orthoester monomers such as 1,6,10-trioxaspiro[4,5]decanes 4 , containing biphenyl mesogens at the C-8 positions of the five- and six-membered spirocyclic ring, through the alkylene spacers of different lengths were prepared by condensation reaction of the corresponding biphenyl mesogenic 1,3-propanediol 3 with 2,2-diethoxytetrahydrofuran, with 50–75% yields. Through cationic double ring-opening polymerization, carried out with boron trifluoride etherate as an initiator (5 mol % vs. monomer) in bulk at 150°C, spiro-orthoester monomers 4 afforded a novel class of side-chain thermotropic LC polymers with a poly(ether ester) as the main chain 8 . The liquid-crystalline properties of the spiro-orthoester monomers and the resulting polymers were examined by differential scanning calorimetry and optical polarized microscopy. Biphase separation was observed in the side-chain liquid-crystalline poly(ether ester)s upon annealing in the broad isotropic region. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2439–2455, 1998     

Tributylstannylated silicic acid as precursor of organofunctionalized silica gel

Tributylstannylated silicic acid (TBSA), which was regarded as a protected polymeric silanol against self-condensation to give silica gel, was newly prepared from the reaction of water glass (WG) and bis(tributyltin) oxide (TBO). The ratios of Si/Sn contained in TBSA were determined by gravimetric analysis to be in the range of 2–3. The gelation of TBSA in usual organic solvents such as hexane, benzene, and dichloromethane was not observed over 3 weeks. In addition, TBSA was shown to be a convenient precursor for the preparations of silica gel modified with organofunctional groups. From the reaction of TBSA with trimethoxysilanes and aromatic alcohols, the silica gels havingorganofunctional groups were obtained with the elimination of a tributyltin group. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 655–663, 1998     

Synthesis and properties of novel poly(arylene ether)s and poly(arylene thioether)s based on a pyridazine biphenol or a phthalazine biphenol

Novel sulfur‐containing biphenol monomers were prepared in high yields by the reaction of 4‐mercaptophenol with chloropyridazine or chlorophthalazine compounds. High‐molecular‐weight poly(arylene ether)s were synthesized by a nucleophilic substitution reaction between these sulfur‐containing monomers and activated difluoro aromatic compounds. The inherent viscosities of these polymers ranged from 0.34 to 0.93 dL/g. The poly(pyridazine)s exhibited glass‐transition temperatures greater than 165 °C. The poly(phthalazine)s showed higher glass‐transition temperatures than the poly(pyridazine)s. A polymer synthesized from a bisphthalazinebiphenol and bis(4‐fluorophenyl)sulfone had the highest glass‐transition temperature (240 °C). The thermal stabilities of the poly(pyridazine)s and poly(phthalazine)s showed similar patterns of decomposition, with no significant weight loss below 390 °C. The poly(phthalazine)s were soluble in chlorinated solvents such as chloroform, and the poly(pyridazine)s were soluble in dipolar aprotic solvents such as N,N′‐dimethylacetamide. The soluble poly(pyridazine)s and poly(phthalazine)s could be cast into flexible films from solution. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 262–268, 2007     

Synthesis and properties of poly (diphenylacetylenes) having aliphatic para-substituents

1-(p-t-Butylphenyl)-2-phenylacetylene and 1-(p-n-butylphenyl)-2-phenylacetylene were polymerized in catalytic systems based on TaCl₅ to give new polymers in high yields. These monomers were more reactive than diphenylacetylene (DPA) in copolymerization. Unlike poly (DPA), the present polymers were soluble in toluene, CHCl₃, etc. owing to the high configurational entropy induced by the para-substituents. Their relative weight-average molecular weights determined by GPC were in the range of 6 × 10⁵–36 × 10⁵, and films could be obtained by solution casting. These polymers were fairly thermally stable, as seen from their high onset temperatures (320–380°C) of weight loss in TGA in air. The oxygen permeability coefficient of the polymer with t-Bu group was 1100 barrers, the highest among those of all the hydrocarbon polymers. © 1994 John Wiley & Sons, Inc.     

Thermal oxidation of blends of poly(ethylene oxide) and poly(methyl methacrylate)

Thermal oxidation of poly(ethylene oxide) (PEO) and its blends with poly(methyl methacrylate) (PMMA) were studied using oxygen uptake measurements. The rates of oxidation and maximum oxygen uptake contents were reduced as the content of PMMA was increased in the blends. The results were indicative of a stabilizing effect by PMMA on the oxidation of PEO. The oxidation reaction at 140°C was stopped at various stages and PMMA was separated from PEO and its molecular weights were measured by gel permeation chromatography (GPC). The decrease in the number-average molecular weight of PMMA was larger as the content of PEO increased in the blends. The visual appearance of the films suggested that phase separation did not occur after thermal oxidation. The activation energy for the rates of oxidation in the blends was slightly increased compared to pure PEO. © 1992 John Wiley & Sons, Inc.     

Synthesis and characterization of poly(itaconate ester)s with etheric side chains

The synthesis and characterization of poly(itaconate ester)s with short poly(ethylene oxide) side chains have been studied. It was found that the monomer syntheses via esterification of itaconic acid resulted in incomplete esterification leaving up to 35 mol % monomers with carboxylic acid functionality. These acid groups were then incorporated into the polymers. This acid incorporation has not previously been reported, nor have the properties of the copolymers been studied. Techniques were developed to effectively remove the acid impurities to generate pure homopolymers. Titration and gas chromatographic techniques were developed to study the amount of acid impurity in the monomers, and titration was also used to characterize the polymers. Size exclusion chromatography and differential scanning calorimetry were used to study both the homopolymers and copolymers. It was found that the location and breadth of the glass transition is a function of acid content. Finally, isomerization of the itaconate monomers to the inactive mesaconate was also found to be a problem during the synthesis. Pure mesaconate and citraconate monomers were synthesized and characterized by ¹H-NMR. © 1993 John Wiley & Sons, Inc.     

Effect of aging on fractional crystallization of poly(ethylene oxide) component in poly(ethylene oxide)/poly(3‐hydroxybutyrate) blends

The effect of aging on the fractional crystallization of the poly(ethylene oxide) (PEO) component in the PEO/poly(3‐hydroxybutyrate) (PHB) blend has been investigated. The partial miscibility of the PEO/PHB blends with high PEO molecular weight (M_v = 2.0 × 10⁵ g/mol) was confirmed by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis. The fractional crystallization behavior of the PEO component in the PEO/PHB blends with low PEO content (not more than 30 wt% of PEO), before and after aging under vacuum at 25 °C for 6 months, were compared by DSC, fourier transform infrared microscopic spectroscopy, small angle X‐ray diffraction, and scanning electron microscopy. It was confirmed that nearly all the PEO components remain trapped within interlamellar regions of PHB for the PEO/PHB blends before aging. Under this condition, the crystallization of PEO is basically induced by much less active heterogeneities or homogeneous nucleation at high supercoolings. While, after the same PEO/PHB samples were stored at 25 °C in vacuum for 6 months, a part of the PEO component was expelled from the interlamellar region of PHB. Under this condition, the expelled PEO forms many separate domains with bigger size and crystallizes at low supercoolings by active heterogeneous nucleation, whereas the crystallization of PEO in the interlamellar region is still mainly induced by less active heterogeneities or homogeneous nucleation at extreme supercoolings. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2665–2676, 2005