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.     

Intramolecular liquid-crystal order in polymers with chain side groups

Hydrodynamic, optical and electro-optical properties of solutions of polyphenyl methacrylic esters of cetyl and nonyl oxybenzoic acids and of random copolymers of the C₁₆ ester with cetyl methacrylate have been investigated.Experimental data show that the molecules of these polymers exhibit intramolecular orientationalpolar order of a mesomorphic type in which the side-chains form a mobile liquid-crystalline structure. The intramolecular mesomorphic state is due to the side chain radical containing groups capable of forming thermotropic nematic liquid crystals.     

Synthesis and mesomorphism of new aliphatic polycarbonates containing side cholesteryl groups

New cholesterol side-functionalised polycarbonate polymers were synthesised by the ring-opening homo- and copolymerisation reaction of the cyclic monomer cholesteryl 5-methyl-2-oxo-1,3-dioxane-5-carboxylate and d,l-lactide using Sn(Oct)₂ as a catalyst. The chemical structures and average molecular weights of the cyclic monomer, homopolymer and block copolymers obtained in this study were characterised using FT-IR, ¹H NMR and gel permeation chromatographic measurement. The mesomorphism and mesophase structure were investigated with polarising optical microscopy, differential scanning calorimetry and X-ray diffraction measurement. As a result, the homopolymer and block copolymers showed an enantiotropic smectic A (SmA) phase. With the concentration of the lactide segment increasing, the glass transition temperature and isotropic temperature of the corresponding block copolymer all decreased. In addition, XRD suggested that the homopolymer and two block copolymers showed the SmA double-layer packing of side chains.     

Complexation behaviour of polymers with pendant cyclodextrin side groups

The influence of the chain conformation on the formation of polymeric supramolecular complexes as well as the influence of the complexation on the conformation of the polymer chain has been studied. The complexation of pyrene into the cavity of β-cyclodextrin (β-CD) was investigated in aqueous solutions of β-CD substituted poly(allylamine) (PAA) under variation of external parameters, i.e. temperature, pH, ionic strength and addition of urea. The observed changes of the complexation constant K for the formation of the 2:1 β-CD/pyrene complex can be explained by a change of the chain flexibility which leads to a variation of the mean distance between neighbouring β-CD-moieties along the polymer chain. The intra-chain association of the decyl group with β-CD in PAA with co-pendant decyl and β-CD is disrupted by the addition of 1-adamantanamine HCl resulting in a more extended structure of the polymer. The β-CD moiety in PAA-CD shows one order of magnitude greater affinity to 2-(p-toluidyl)naphthalene-6-sulfonate than the native β-CD and the affinity increases further by the presence of decyl side groups.     

侧基含偶氮基的硅氧烷梳状聚合物的光致变色性

本文研究了对十一烯酰胺基偶氮苯及其硅氧烷均聚、共聚的梳状聚合物在溶液或薄膜状态下的光致变色性和热回复性。它们的反、顺异构体组分比随光照时间趋于某稳定值, 该稳定的组分比与照射光波长有关。光异构反应是可逆的。比较了异构反应速率和异构转换率, 以聚硅氧烷共聚物PSII3A[侧基比(M1/M2)=1/9, M1是对十一烯酰基偶氮苯, M2是对十一烯酰氧对氧基苯酯]为最佳。升高温度能增进热回复异构。     

Thermal effects on liquid-crystalline order in polymers with mesogenic side groups

X-ray studies on polymers with phenyl benzoate side groups separated from the main chain by spacer groups of various lengths have been performed. It was found that the dimensions of liquid-crystalline regions are 15–20 nm, and they contain four to six close-packed layers. Thermal changes in x-ray scattering are associated with the variation of sizes and concentration of liquid-crystalline regions determined by the mobility of the main chain.     

Secondary mechanical relaxation effects in some cycloalkyl side groups containing polymers

Summary The dynamic mechanical properties at acoustic and low-ultrasonic frequencies (6–60 kHz) have been determined in polycyclopentylmethacrylate (PCPMA), polycyclohexylmethacrylate (PCHMA), polycyclohepthylmethacrylate (PCHpMA), polycyclooctylmethacrylate (PCOcMA), polycyclohexylacrylate (PCHA), polyvinylhexahydrobenzoate (PVHHBz), polyvinylcyclohexylether (PVCHE) and polyvinylcyclohexane (PVCH) Measurements were carried out by an electrostatic method (flexural vibrations) over the temperature range 60 °K to room temperature. All polymers, except for polyvinylcyclohexane, exhibit a γ-relaxation, connected with internal motion of the cycloalkyl ring, whose activation parameters depend exclusively on the nature of the ring. PVCHMA, PVCHA, PVHHBz, PVCHE and PVCH exhibit a further secondary relaxation effect (δ-process) at lower temperature, whose position on the temperature scale, strength (peak height) and activation parameters depend on the nature of the units to which the cyclohexyl ring is attached. The δ-process is attributed to some complex motion of the whole cyclohexyl ring, involving oscillatory rotation of the same around simple bonds which link it to the backbone chain. Contrarily to the δ-process of the phenyl side group containing polymers, the δ-process of the polymers here examined seems to be more sensibly dependent on intramolecuar effects.

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Zusammenfassung Es wurden die dynamischen Eigenschaften im akustischen und im Bereich langsamer Ultraschallfrequenzen (6–60 kHz) untersucht für Polycyclopentylmethacrylat (PCPMA), Polycyclohexylmethacrylat (PCHMA), Polycycloheptylmethacrylat (PCHpMA), Polycyclooctylmethacrylat (PCOcMA), Polycyclohexylacrylat (PCHA), Polyvinylhexahydrobenzoat (PVHHBz) Polyvinylcyclohexyl?ther (PVCHE) und Polyvinylcyclohexan (PVCH). Die Untersuchungen wurden mit einer elektrostatischen Methode (Biegeschwingung) über den Temperaturbereich von 60 °K bis Raumtemperatur durchgeführt. Alle Polymeren, au?er Polyvinylcyclohexanen, zeigen eine γ-Relaxation verbunden mit internen Bewegungen des Cycloalkylrings, deren Aktivierungsparameter wesentlich von der Natur des Rings abh?ngen. PVCHMA, PVCHA, PVHHBz, PVCHE und PVCH zeigen einen weiteren sekund?ren Relaxationseffekt (δ-Proze?) bei tieferen Temperaturen, dessen Lage in der Temperaturskala, St?rke (Peakh?he) und Aktivierungsparameter von der Natur der Einheiten abh?ngen, an welchen der Cyclohexylring h?ngt. Der δ- Proze? wird irgendeiner komplexen Bewegung des ganzen Cyclohexylrings zugeschrieben, eingeschlossen oszillatorische Rotation desselben um die Einfachbindung, die ihn mit der Hauptkette verbindet. Anders als der δ-Proze? der Phenylseitengruppen enthaltenden Polymerenketten scheint der hier untersuchte δ-Proze? emfindlicher von intramolekularen Effekten abzuh?ngen.

     

Conductivity of nonaqueous solutions of aromatic polymers containing ionizable side groups

The concentration dependence of the equivalent conductivity has been measured for dilute DMAc solutions of K, Na, and Li salts of aromatic polymers with ionizable side groups [poly(diphenylenesulfophthalide) and poly(arylene ether ketone) with side COOH groups]. A correlation between the concentration dependences of the equivalent conductivity and reduced viscosity shows that the first parameter initially sharply decreases with an increase in concentration and then achieves a limiting value at a rather low concentration and that precisely in this concentration range the polyelectrolyte effect manifests itself in the concentration versus reduced viscosity curve. With an increasing amount of metal ions incorporated into the polymer, the equivalent conductivity grows. It was demonstrated that the type of counterion affects the reduced viscosity and equivalent conductivity of salt solutions. This effect depends on the structure of the polymer backbone: for poly(arylene ether ketone) salts, the reduced viscosity and the equivalent conductivity increase in the sequence Li → Na → K, while for poly(diphenylenesulfophthalide) salts, the reduced viscosity increases in the reverse order and the equivalent conductivity remains almost invariable. The limiting values of the equivalent conductivity and the degree of association of polyelectrolytes have been estimated in terms of the Arrhenius-Ostwald theory. It has been shown that, in the case of poly(diphenylenesulfophthalide) salts, the equivalent conductivity and the degree of association are higher than those for poly(arylene ether ketone) salts with side COOH groups. This finding is indicative of a stronger binding of counterions by poly(arylene ether ketone).     

Glass transition temperatures of some linear polymers containing phenyl side groups

The glass transition temperatures of a number of poly(vinyl phenyl ketones), poly-(vinyl benzoates), and poly(phenyl acrylates) have been measured by a refractometric method. The effects exerted on T_g by the nature and position of the ring substituents and by the different groups binding the pendant phenyl rings to the polyvinyl chain are discussed. The importance of knowledge of the side-group motions in the glassy state for the interpretation of glass temperature data is emphasized.     

Ferrocene-containing polymers. XIII. Polymeric compounds possessing carboxyphenyl side groups

As an extension of earlier work on the condensation of ferrocene with aldehydes, the polycondensation of ferrocene with p- and o-carboxybenzaldehyde is described. While, in the former case, regular polycondensation occurs giving rise to a polymer composed of ferrocenylene and 4-carboxybenzal units, a deviation from this route is observed in the o-carboxybenzaldehyde case, where a polymer containing both carboxybenzal and 3,3-phthalide bridging units between the ferrocenylene groups is formed instead. This unexpected behavior can be accounted for by a hydride abstraction mechanism. In support of the polymer structure proposed, 3-ferrocenylphthalide and 3,3-diferrocenylphthalide are isolated as intermediates or by-products. In both polymer series, number-average molecular weights up to 3000 (unsubfractionated) are measured. The polymers are soluble in a number of organic solvents and can be cured with epoxides.     

Photoregulation of the optical properties of comb-shaped polymers with mesogenic side groups

A new approach for photoregulation of supramolecular structure and optical properties of polyacrylic copolymers bearing azobenzene and cyanobiphenyl mesogenic groups is presented. The detailed study of photooptical behaviour, kinetics of photoinduced optical birefringence and mechanism of structural transformations taking place during a laser illumination are discussed.     

Acrylic monomers and polymers with perfluoroalkylated biphenyl side groups: synthesis and phase transitions

New perfluoroalkylated acrylic monomers with a biphenyl core and hydrocarbon spacer (CH₂)_m of various length (m = 0, 6, 11) were synthesized from biphenol. Phase transitions of monomers and intermediates isolated in the course of the synthesis were studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Whereas most fluoroacrylic monomers and low molecular weight precursors displayed thermotropic behavior (whatever the length of the spacer), the polymers did not retain the ability to form mesophases. Moreover, the bulk organization of the fluorinated side groups was diminished strongly for polymers in comparison with the corresponding fluorinated monomers. Nevertheless, it was demonstrated that an intermediate length of the spacer (-CH₂)₆, could favor the organization of the rigid perfluoroalkylated biphenyl side groups in the bulk.     

Synthesis and characterization of polymers containing linear sugar moieties as side groups

The synthesis of a water-soluble monomer, namely 4-vinylphenyl-d-gluco(d-manno)hexitol (4) derived from d-gluconolactone, is here presented. The homopolymerization of the vinylsugar has been conducted in both aqueous and organic media using free-radical initiators. High-molar-mass water-soluble polymers are obtained. The copolymerization behavior of the vinylphenyl sugar monomer with a hydrophilic monomer such as acrylamide, as well as with a hydrophobic monomer such as styrene, has been investigated. Statistical- and block-type copolymers have thus been prepared. The structures of the polymers were confirmed by NMR and their thermal properties examined by DSC.     

具有极性大侧基乙烯基聚合物的分子尺寸和均方二极矩

基于旋转异构态模型和生成矩阵代数方法,重新推导了大侧基聚合物均方回转半径和均方二极矩等基础量公式,应用于对聚乙烯咔唑（PVK）、聚对氯苯乙烯（PPCS）、聚乙烯砒啶（P2VP）和聚乙烯砒咯烷酮（PVP）链构象-构型依赖性质的研究.计算得到其无规链的均方二极矩特征比分别为0.55、0.57、0.48和0.37,均方回转半径特征比分别为2.07、1.74、1.11和1.52,全同链温度系数在？6.1×10？3～2.1×10？3K？1之间,范围比间同和无规链大.比较各特征比变化曲线规律,发现PPCS、PVP和P2VP的基础量分别受聚合物聚合度、规整程度和构象能的影响相对比较明显,而大侧基使PVK的均方二极矩和均方回转半径特征差异显著;对照改进的计算结果表明,在计算均方二极矩和回转半径时考虑极性侧基的方向和尺寸是十分重要的,在聚合物极性和柔性分析中不能忽略极性大侧基的影响.     

Photoinduced chirality in achiral liquid crystalline azobenzene polymers containing different polar side groups

Circular dichroism (CD) was induced in the films of two achiral liquid crystalline polymers, poly[(4′-(6-(methacryloyloxy)hexyl)oxy)-(4-X)azobenzene] (PM6X, X = C and N for cyano and nitro, respectively), by irradiation with one handed circularly polarized light (CPL) at 442 nm. The CD and UV spectra of the polymeric films suggest that left-CPL induces a left helical structure and right-CPL reverses the resulting structure into a right helix. For PM6C, the photoinduced CD values of the nematic film are much higher than in the casting and isotropic film. The photoinduced chirality of PM6C films is higher than PM6N due to a higher polarity of nitro groups in PM6N. The PM6N’s CD intensity around 450 nm is increased with the irradiation time of linearly polarized light (LPL) followed by left-CPL irradiation. The correlation between azobenzene chromophores and circularly polarized light will be discussed in the paper.     

Metallorganic side group liquid crystalline polymers containing pi-allylpalladium(II) groups

The preparation and phase properties of some LC pi-allyl and pi-crotyl Pd(II) side group metallorganic polymers and some related salicylaldiminates are described. The LC acrylate functionalized monomers are easily prepared, but their use to obtain the corresponding polymers by radical reaction failed because extensive decomposition of the complexes occurs with the formation of Pd metal. The synthesis of the metallated polymers was therefore performed by reacting the dimeric chloro-bridged organometallic pi-allyl or pi-crotyl Pd(II) complexes with the appropriate ligand polymer which is prepared without difficulties. The organometallic polymers show a nematic mesophase, while the ligand polymer exhibits a smectic A or C phase. Both metallated low molecular mass model compounds and the polymers give stable mesophases, although at lower temperatures compared with the parent ligand compounds.     

Polyimides with side groups: Synthesis and effects of side groups on their properties

Polyimides are a class of well-known high-performance polymers combined the excellent mechanical, electrical, and thermal properties and widely applied in many high-tech fields. Traditional polyimides can only be processed in the state of soluble intermediates with a hazardous step of cyclodehydration and elimination of a nonvolatile polar solvent. Therefore, a great effort has been devoted to the development of soluble polyimides that can be processed in the full imidation state. The incorporation of side groups into the polyimide backbone is an efficient approach to resolve above problems with a little sacrifice of its inherent merits. The subtle variation of side groups in polyimide backbones has allowed researchers to tune their final properties. In particular, some special side groups can endow polyimides the specific property or functionality to broaden their application fields. In this article, we summarize the synthesis of polyimides with side groups in recent 20 years and further discuss the effect of side groups on their physical and specific properties. The future research directions of polyimides with side groups are also discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 533–559