Synthesis and physico-chemical properties of poly[4-(1,1,3,3-tetramethylbutyl)phenyl methacrylate]

Poly[4-(1,1,3,3-tetramethylbutyl)phenyl methacrylate] ( 1a ) was synthesized and its physicochemical properties were determined in the condensed phase and in dilute solution. The polymerization of 4-(1,1,3,3-tetramethylbutyl)phenyl methacrylate was carried out by radical mechanism in solution with 2,2′-azoisobutyronitrile as initiator. Several samples were characterized by their intrinsic viscosity, by osmometric measurements, differential scanning calorimetry, and X-ray diffraction. The viscometric behaviour of fractions of 1a was studied in good solvents and theta solvents, and the conformational parameters were calculated. Polymer 1a presents an unusual high rigidity in the chain. X-Ray diffraction of this polymer indicates a one-dimensional ordering of a mesomorphic type.     

Viscosities of dilute solutions of poly(tetrahydrofurfuryl methacrylate)

The intrinsic viscosities of seven fractions (from M?_n = 1,69.10⁵ to M?_n = 6,13.10⁵) of poly(tetrahydrofurfuryl methacrylate) in eleven solvents at temperatures between 30° and 50° show the following order: tetrachloroethane > dichloroethane > tetrahydrofuran > chloroform > benzene > bromobenzene > ethyl acetate > carbon tetrachloride > methyl pentyl ketone > acetone > 2-hydroxymethyltetrahydrofuran. Values of HUGGINS slope constants range between 0,34 to 0,48 for the unfractionated polymer and the magnitudes of a and k in the expression [η] = kM^a show little variations with temperature in case of good solvents whereas the opposite is observed in case of poor solvents. The theta temperature for 2-hydroxymethyltetrahydrofuran containing 20% methanol is 31,2 ± 0,3° and 3,49, 5,72, and 4,97 are the values for K₀.10⁴, (r /M)^1/2.10⁹ and (r /Z)^1/2.10⁸, respectively.     

Viscosities of dilute solutions of poly (methyl methacrylate) and poly (ethyl methacrylate) in organic solvents

Poly(methyl methacrylate) and poly(ethyl methacrylate) prepared by a benzoylperoxide catalysed polymerization process were fractionated. The variation of the intrinsic viscosity and HUGGINS ' constant with temperature, molecular weight and solvent was studied. From the viscosity data the thermodynamic interaction parameters χ, ψ, k etc., and the solubility parameter of the polymers were evaluated and discussed.     

Viscosity and intrinsic viscosity/temperature relationships for dilute solutions of poly(2-biphenylyl methacrylate) and poly(4-biphenylyl methacrylate)

The actual viscosity η and the intrinsic viscosity [η] of six fractions of poly(2-biphenylyl methacrylate) {poly[1-(2-biphenylyloxycarbonyl)-1-methylethylene], (POB); weight average molecular weight M?_w: 4,0 · 10⁴ to 1,42 · 10⁶, polydispersity ratio M?_w/M?_n ≈ 1,4} and of three fractions of poly(4-biphenylyl methacrylate) {poly[1-(4-biphenylyloxycarbonyl)-1-methyl-ethylene], (PPB); M?_w : 8,1 · 10⁴ to 5,3 · 10⁵, M?_w/M?_n ～ 1,4} in benzene have been determined at different temperatures between 20 and 60°C. Values of the apparent activation energy of the viscous flow Q and the pre-exponential term A in the expression η = A · exp[Q/(RT)] have been obtained. Q varies with M?_w and concentration c according to Moore's equation: Q = Q₀ + K_e · M · c, where Q₀ refers to the solvent and K_e depends on polymer and solvent. The numerical value of K_e for POB and PPB is 1,6 · 10^?4 (6,7 · 10^?4) and -8,1 · 10^?4 cal · dl · g^?1 (-3,4 · 10^?3 J · dl · g^?1), resp. From all polymethacrylates studied POB is the only polymer with a positive K_e value. The positive value of K_e for POB may possibly be related to the more extended form of POB in benzene and also may be connected, at least partly, with its low flexibility. The temperature coefficient of the unperturbed dimensions dln〈r₀²〉/dT for POB estimated from the viscosity data using the Burchard-Stockmayer-Fixman relation, is 0,14 · 10^?3, much lower than for PPB (2,3 · 10^?3 between 22 and 40°C and 1,2 · 10^?3 between 40 and 60°C). The positive values of dln〈r₀²〉/dT indicate that extended conformations of these polymers in benzene must be associated with higher energies.     

Solution properties and unperturbed dimensions of poly(5-p-methyl methacrylate) and poly(2-tert-butylphenyl methacrylate)

The solution properties of poly(5-p-menthyl methacrylate) and poly(2-tert-butylphenyl methacrylate) are determined by several methods in good and ideal solvents. The flexibilities σ calculated on the basis of the unperturbed dimensions are 3,1 and 2,6, resp. These values are compared with those found for other polymethacrylates with bulky substituents. The influence of a large group in ortho position at the cyclohexyl and the phenyl rings is discussed in terms of steric hindrance and specific interactions.     

Adsorption of poly(4-tert-butylphenyl methacrylate) on silica from THF/water

Adsorption studies of poly(4-tert-butylphenyl methacrylate) (PBPh) on silica from a binary solvent (THF/water) are reported. In order to investigate the influence of the composition of the binary solvent on the adsorption of the polymer on a special silica with hydrophobic surface, measurements of the adsorption isotherms were carried out using Aerosil R-972. The adsorption isotherm of PBPh for the hydrophobic silica/THF solution interface exhibits higher values than the isotherms for hydrophobic silica/aqueous THF solution interfaces. The amount of adsorbed polymer decreases when the water content of the binary mixture increases. The results are discussed in relation to the effects of preferential adsorption of one of the solvents by the polymer.     

Viscosity/temperature relationships for dilute solutions of poly(2,4,5-trichlorophenyl methacrylate)

The actual viscosity η of six fractions of poly(2,4,5-trichlorophenyl methacrylate) (PTCPh) with weight-average molecular weight M?_w, ranging from 9,11 · 10⁴ to 94,8 · 10⁴, was determined in benzene at a number of temperatures from 22 to 60°C. The variation of the pre-exponential term A and the apparent activation energy of viscous flow Q, with molecular weight and concentration was studied. Moore's equations are valid for PTCPh. The temperature coefficient of the unperturbed dimensions dln 〈r²₀〉/dT estimated from the intrinsic viscosity data by using the Burchard-Stockmayer-Fixman relation, is ?3 . 10^-3 (from 22 to 40°C) and ?0,87 . 10^-3 (from 40 to 60°C). These negative values indicate that extended configurations of PTCPh in benzene must be associated with lower energies.     

Ion-aggregation in poly[ethylene-co-(2-(4-carboxyphenoxy)ethyl methacrylate)] and poly[ethylene-co-(2-(3-carboxypyridin-6-yloxy)ethyl methacrylate)] based ionomers

Two new ethylene ionomers were synthesized, poly[ethylene-co-(5.4-mol-% 2-(4-carboxyphenoxy)ethyl methacrylate)] partially neutralized with Zn(II) (EMAA-BZnX), and poly[ethylene-co-(5.4 mol-% 2-(3-carboxypyridin-6-yloxy)ethyl methacrylate)] (EMAA-N) and its hydrochloride (EMAA-NHCl). Differential scanning calorimetric (DSC), X-ray diffraction, and dielectric and dynamic mechanical relaxation studies were made for the two ionomers to investigate the formation and structure of ionic aggregates. In EMAA-BZnX, DSC, dielectric and dynamic mechanical data suggest the formation of ionic aggregates in the neutralization range above 40%; X-ray diffraction data, however, did not show any ionic peak, while the ionic groups were not aggregated at all in EMAA-NHCl. From these results, the ion-aggregation in ionomers is discussed with respect to chemical structure and the nature of ionic groups.     

Darstellung und spektroskopische analyse von oligo{[4-(1,1,3,3-tetramethylbutyl) (bzw. 4-octyl)-2-hydroxy-1,3-phenylen]methylen}en und ihrer Ausgangsverbindungen

4-(1,1,3,3-Tetramethylbutyl)phenol and 4-octylphenol, obtained by Fries rearrangement of the corresponding phenyl carboxylates and subsequent reduction of the carbonyl group, were monobrominated in ortho-position and hydroxymethylated with formaldehyde. Originating from these compounds, six 2,2′-methylenediphenol ( 2a–f ) as well as seven 2,6-bis(2-hydroxybenzyl)phenol derivatives ( 3a–g ) were prepared, which have methyl, 1,1,3,3-tetramethylbutyl, and octyl substituents in various ratios in para-position to the phenolic hydroxy groups. The IR- and ¹H-NMR-spectroscopical analyses confirmed the assumed structures of the synthesized oligo-nuclear phenolic compounds.     

The molecular structure of 4-(dimethylmaleimido)phenyl methacrylate

The molecular structure of 4-(dimethylmaleimido)phenyl methacrylate was determined by means of X-ray diffraction. Crystals are orthorhombic, space group F2dd, a = 3,993(1) Å, b = 36,650(6) Å, c = 39,460(8) Å and Z = 16; d_calc = 1,360 g · cm^?3, V = 5774,7 ų, M = 285,3, λ = 0,7107 Å, μ (MoK_α) = 1,06 cm^?1, F(000) = 2400. The structure was solved by direct methods and refined to R = 0,062 for 304 observed reflections. The molecule has a synperiplanar conformation as to the C?C and C?O double bonds about C(7)? C(8) and also as to the C?O and C? O bonds about C(7)? O(1).     

Study on antithrombogenicity of poly[beta-(acetylsalicylyloxy)ethyl methacrylate] relative to poly(hydroxyethyl methacrylate)

The antithrombogenicity of a polymer made of aspirin bound to hydroxyethyl methacrylate (HEMA), abbreviated as ASA-polymer, was compared with that of poly(hydroxyethyl methacrylate) (PHEMA). Platelet from platelet rich plasma (PRP) incubated with ASA-polymer surface exhibited noticeable decreases in adhesion and aggregation as compared to platelets incubated with PHEMA. Low molecular weight components other than aspirin, which may be released from ASA-polymer during the incubation with PRP, or contact with ASA-polymer causing denaturation of platelets without morphological changes could be responsible for the decrease of adhesion and aggregation. Both PRP and PPP exposed to ASA-polymer-coated surfaces exhibited a much smaller partial thromboplastin time (PTT) than if exposed to PHEMA-coated surfaces; the PTT of ASA-polymer was similar to that of glass exposed plasma. With respect to the in vivo antithrombogenicity, the ASA-polymer surface led to thrombus formation. This may be due to the partial hydrolysis of the acetyl groups resulting in the formation of a negatively charged surface which in turn accelerates the coagulation cascade despite its inhibitory effects on platelet adhesion and aggregation. On the other hand, neointima formed around a thrombus layer on PHEMA-coated sutures after 14 days.     

Liquid-crystalline polymers containing heterocycloalkanediyl groups as mesogens, 6. Liquid-crystalline poly[trans-11-{4-[5-(4-methoxyphenyl)-1,3-dioxan-2-yl]-2,6-dimethylphenoxy}undecyl methacrylate] and poly[trans-11-{4-[5-(4-methoxyphenyl)-1,3-dioxan-2-yl]-2,6-dimethylphenoxy}undecyl acrylate]

The synthesis and characterization of poly[trans-11-{4-[5-(4-methoxyphenyl)-1,3-dioxan-2-yl]-2,6-dimethylphenoxy}undecyl methacrylate] and poly[trans-11-{4-[5-(4-methoxyphenyl)-1,3-dioxan-2-yl]-2,6-dimethylphenoxy}undecyl acrylate] is presented. Both polymers exhibit nematic mesophases and do not present side-chain crystallization. At temperatures higher than 160°C the 1,3-dioxane-2,5-diyl groups undergo a thermally induced trans-cis isomerization. A radical mechanism is proposed for this isomerization.     

Synthesis and properties of liquid-crystalline AB-block copolymers poly[6-(4′-methoxy-4-biphenylyloxy)hexyl methacrylate]-block-polystyrene

Liquid-crystalline AB-block copolymers poly[6-(4′-methoxy-4-biphenylyoxy)hexyl methacrylate]-block-polystyrene were synthesized by direct coupling of the homopolymers with functional end groups. Like the liquid-crystalline homopolymer with mesogenic units in the side chain, all block copolymers show a nematic mesophase. The transition temperatures are hardly affected by the composition and molecular weight of the block copolymers.     

Dynamic mechanical behaviour and phase separation of mixtures of polysulfone with bis[4-(4-ethynylphenoxy)phenyl]-sulfone or poly(phenylene sulfide)

The dynamic mechanical behaviour and microphase-separation structure of polysulfone blends with bis[4-(4-ethynylphenoxy)phenyl]sulfone and with poly(phenylene sulfide) were investigated using torsional braid analysis and scanning electron microscopy. The experimental results showed that the size and shape of dynamic mechanical damping peaks and the structure characteristics of polysulfone blends with sulfur-containing polymers do not only depend on the chemical and physical nature and the weight fractions of the two components but also on conditions of thermal treatment leading to cross-linking reactions. In these multi-component polymer systems, the initially compatible mixture turns into an incompatible two-phase system during heating.     

New poly(amide-imide)s syntheses, 14. Preparation and properties of poly(amide-imide)s based on 3, 3-bis[4-(4-trimellitimidophenoxy)phenyl]-1-oxoisoindoline

An imide ring-containing dicarboxylic acid, 3,3-bis[4-(4-trimellitimidophenoxy)phenyl]-1-oxoisoindoline, was prepared via condensation of 3,3-bis[4-(4-aminophenoxy)phenyl]-1-oxoisoindoline and trimellitic anhydride. A series of new aromatic bis(phenoxy)-1-oxo-isoindoline-containing poly(amide-imide)s were prepared via direct polycondensation of this diimide-diacid with various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in N-methyl-2-pyrrolidone (NMP) in the presence of calcium chloride. Most of the resulting polymers are of amorphous nature and readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All soluble poly(amide-imide)s afford transparent, flexible, and tough films. The glass transition temperatures of the polymers are in the range of 267–305°C and show almost no weight loss up to 450°C in nitrogen atmosphere. The properties of 1-oxoisoindoline containing poly(amide-imide)s are compared with those of the corresponding analogous poly(amide-imide)s derived from 3,3-bis[4-(4-trimellitimidophenoxy)phenyl]phthalide.     

The behaviour of poly(2,3-epoxypropyl methacrylate) in dilute solution

Homopolymers of 2,3-epoxypropyl methacrylate with various molecular masses were prepared by solution polymerization with 2,2′-azoisobutyronitrile as initiator. The effect of polymerization conditions on the molecular parameters (weight- and number-average molecular masses M_W and M_n intrinsic viscosity [η]) and the tacticity of the resulting poly (2,3-epoxypropyl methacrylate)s was investigated. For unfractionated polymers, the constants of the Mark-Houwink equation for 1,4-dioxane and tetrahydrofuran were determined. Gel permeation chromatography was tested as a tool for the determination of the M_w and M_n values.     

New poly(amide-imide) syntheses, 19. Preparation and properties of poly(amide-imide)s derived from N-phenyl-3,3-bis[4-(4-aminophenoxy)phenyl]-1-oxoisoindoline and various bis(trimellitimide)s

A series of novel bis(phenoxy)-1-oxoisoindoline-containing poly(amide-imide)s 3 were synthesized by the direct polycondensations of N-phenyl-3,3-bis[4-(4-aminophenoxy)-phenyl]-1-oxoisoindoline ( 1m , NPBA) with various aromatic bis(trimellitimide)s 2 in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Poly(amide-imide)s 3 having inherent viscosities up to 1,06 dL/g were obtained in quantitative yields. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvent such as NMP and N,N-dimethylacetamide. All of the soluble poly(amide-imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 277–327°C, and the 10% weight loss temperatures were above 500°C in nitrogen. The properties of poly(amideimide)s 3 were compared with those of the corresponding isomeric poly(amide-imide)s 3 ′ prepared from NPBA and various aromatic diamines.     

Synthesis and characterization of new cardo polyamides derived from 8,8-bis[4-(4-aminophenoxy)phenyl]tricyclo[5.2.1.02,6]decane

A series of novel cardo polyamides were prepared by direct polycondensation of 8,8-bis[4-(4-aminophenoxy)phenyl]tricyclo[5.2.1.0^2,6]decane and various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. The polymers were produced with high yield and moderate to high inherent viscosities of 0.71–1.40 dL·g^–1. Nearly all the polymers could be readily dissolved in polar aprotic solvents such as NMP, N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide, dimethyl sulfoxide as well as less polar solvents such as pyridine and γ-butyrolactone. The polymers were solution-cast from DMAc solution into transparent, flexible, and tough films which were further characterized by X-ray and mechanical analysis. Nearly all the polymers were amorphous, and the polyamide films had a tensile strength range of 97–111 MPa, an elongation at break range of 9–11%, and a tensile modulus range of 1.9–2.3 GPa. The polyamides had glass transition temperatures between 251–272°C and 10% weight loss temperatures in the range of 468–490 and 499–532°C in nitrogen and air atmosphere, respectively.     

Properties of poly[N-2-(methyacryloyloxy)ethyl-N,N-dimethyl-N-3-sulfopropylammonium betaine] in dilute solution

Poly[N-2-(methacryloyloxy)ethyl-N,N-dimethyl-N-3-sulfopropylammonium betaine] (1) which is an interesting polyzwitterion polymer by virtue of its “antipolyelectrolyte solution behaviour” has been prepared by free-radical initiated polymerization in aqueous solution. Isothermal fractionation was conducted at 294 K employing formamide as solvent and acetone as precipitant. Twelve fractions covering a wide range of weight-average molecular weight (215 000 ≤ M̄_w ≤ 2 070 000) were used to characterise the polymer by light scattering, membrane osmometry and viscosity measurements. The Mark-Houwink equations, established for 1 in two good solvents, 2,2,2-trifluoroethanol (TFE) and 1,0 M aqueous NaCl solution, show that the polymer has a random coil configuration and that TFE is a thermodynamically better solvent than 1,0 M aqueous NaCl solution. The random coil configuration of 1 in TFE was confirmed from the dependence of the polymer dimensions on molecular weight.