Preparation and Properties of Thermotropic Mesogenic Polyesters

Makaruk, Leszek; Polanska, Hanna; Ksiezakowska, Elzbieta; Ważyńska, B.

doi:10.1295/polymj.17.1055

Cited by 9 publications

(9 citation statements)

References 14 publications

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“…Although some of the amide-containing bisphenols shown in Table have been prepared previously (using various synthetic methodologies), ,,,− the process shown in Scheme provides a straightforward general synthesis of 3 − 15 . Bisphenols which contain a single amide unit ( 16 − 18 ) are known in the literature. − The syntheses of 4,4‘-dihydroxybenzanilide ( 16 ) and 3,3‘-dihydroxybenzanilide ( 17 ) were carried out using modifications of existing procedures as described in the Experimental Section. Compound 18 , N -(4-hydroxyphenyl)salicylamide, was obtained commercially.…”

Section: Resultsmentioning

confidence: 99%

Poly(hydroxy amide ethers): New High-Barrier Thermoplastics

et al. 1996

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The synthesis of a new class of high-barrier polymers, poly(hydroxy amide ethers), is described. The polymers are formed by the reactions of bisphenol-A diglycidyl ether, OCH2CHCH2OC6H4C(CH3)2C6H4OCH2CHCH2O, and amide-containing bisphenols of the general formula HOC6H4NHC(O)RC(O)NHC6H4OH [R = −(CH2) n −, −CH2C6H4CH2−, or −C6H4−] or HOC6H4NHC(O)C6H4OH at 140−160 °C in propylene glycol monophenyl ether solvent using ethyltriphenylphosphonium acetate as initiator. High-molecular-weight poly(hydroxy amide ethers) of the general structure [−CH2CH(OH)CH2OC6H4C(CH3)2C6H4OCH2CH(OH)CH2OC6H4NHC(O)RC(O)NHC6H4O−] n or [−CH2CH(OH)CH2OC6H4C(CH3)2C6H4OCH2CH(OH)CH2OC6H4NHC(O)C6H4O−] n are readily prepared. The amorphous thermoplastics have glass transition temperatures (T g) of 90−133 °C and oxygen transmission rates (O2TR) which range from 0.7 to 4.6 cc·mil/100 in.2·atm·day (barrier units or BU) at 23 °C and 47−85% relative humidity. The effect that polymer structure has on oxygen barrier properties and T g is described. The characterization, structure determination, and properties of the poly(hydroxy amide ethers), as well as the amide-containing bisphenol precursors, are also presented.

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Section: Resultsmentioning

confidence: 99%

Poly(hydroxy amide ethers): New High-Barrier Thermoplastics

et al. 1996

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“…The pure polymer Tlp data can be fit with the fractional exponential form using a known value of the intermolecular second moment, S = 1.8 X 2 mT2 and by adjusting the value of the fractional exponent, the apparent activation energy, and Arrhenius prefactor of the correlation time t. The equation employed for Tlp is 1/Tlp = (2/3b2S[1.5Je(2a>e) + 2.5«71( ) + </2(2 )] (4) where <ve = yHI{, y is the gyromagnetic ratio, is the Larmor frequency, and J is the spectral density or the Fourier transform of the correlation function. The radio frequency field amplitude is Hl(.…”

Section: Discussionmentioning

confidence: 99%

“…Either mechanical loss peaks can be introduced by the addition11,15,16 of diluent, or peaks present in the pure polymer can be suppressed. [1][2][3][4][5][6][7][8] In general, a diluent is said to plasticize a polymeric glass if the modulus is lowered upon addition of the diluent. This would be associated with an increase in mechanical loss below the glass transition.…”

Section: Introductionmentioning

confidence: 99%

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An NMR study of plasticization and antiplasticization of a polymeric glass

Liu¹,

Roy²,

Jones³

et al. 1990

Macromolecules

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Films of glassy polycarbonate (BPA-PC) containing relatively low concentration of the diluent di-n-butyl phthalate were studied in two series of NMR experiments. In the first series proton TV measurements were made on polycarbonate with deuterated methyl groups containing perdeuterated diluent up to a concentration of 25 wt %. Under these circumstances the proton relaxation times monitor the x flips of the phenylene groups that is related to the principle sub-glass transition mechanical loss. As the phthalate diluent is first added, the modulus increases slightly and the loss peak is suppressed. The T\ at 44 kHz data show a minimum at about -40 °C which corresponds to the mechanical loss at 1 Hz and a temperature of -100 °C. The Tlp minimum is changed by the addition of diluent in a selective manner. At a diluent concentration of 5 wt % the low-temperature part of the minimum corresponding to the most mobile phenylene groups is suppressed. The remaining minimum is narrower and is shifted slightly to higher temperatures by the removal of the component of the distribution of relaxation times which leads to the low-temperature side. As the concentration of diluent is raised to 10 and 25 wt %, a second lower temperature minimum appears. This minimum is attributed to enhanced motion of repeat units in contact with microscopic clusters of diluent. A lattice model is presented which accounts for suppression of motion at low concentrations and the appearance of the second minimum at higher concentrations. Suppression is associated with improved packing caused by the presence of an isolated diluent molecule in contact with a polymeric repeat unit while enhanced mobility is caused by the presence of a microscopic diluent cluster in contact with a repeat unit. This same lattice model is used to reinterpret a carbon-13 spin diffusion study of the same diluent-polymer system where one ester group on the diluent is labeled. The lattice interpretation of the spin diffusion data reinforces the earlier interpretation in terms of a preferred spatial location of the diluent relative to the polymeric repeat unit. The new interpretation also indicates an increased rate of spin diffusion per diluent molecule at low concentrations, which indicates stronger interactions with the polymer in this regime, in agreement with the suppression of motion observed in the proton Tlp data.

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“…LC polyester was prepared through polycondensation reaction [9] at 4 ~ of the mixture of the bisphenols: 2,2-bis/4-hydroxyphenyl/-1,1-dichloroethylene, 4,4'-dihydroxybenzophenone and 2,2-bis/4-hydroxyphenyl/propane/molar ratio 0.2:0.7:0.1/with sebacoyl dichloride in molar ratio I : 1. Molecular weight of the ohgomeric sample was 3 700.…”

Section: Samplesmentioning

confidence: 99%