Thermodynamics of Linear Poly(pentamethylene urethane) and Poly(hexamethylene urethane) in the Range from 0 to 450 K

Kulagina, T. G.; Смирнова, Н. Н.; Markin, A. V.; Meijer, E. W.; Versteegen, Ron M.

doi:10.1002/macp.200300039

Cited by 14 publications

(8 citation statements)

References 9 publications

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“…Recently, some of us12 have described a feasible preparation method that makes n ‐PUR much more accessible, a fact that has raised the interest for these polymers. Very few is known however about the structure and properties of n ‐PUR; regarding their thermal properties, we12 and Höcker and coworkers13 reported exploratory accounts of the melting behavior displayed by the family of n ‐PUR, and Lebedev et al,14 have published a number of works dealing with the thermodynamic properties of a selection of these polymers. To our knowledge no study on the crystallization behavior of n ‐PUR has been published so far.…”

Section: Introductionmentioning

confidence: 99%

Crystallization studies on linear aliphatic n‐polyurethanes

Fernández

Bermúdez

Versteegen

et al. 2009

J Polym Sci B Polym Phys

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Scheme 2. Possible hydrogen-bonded chain arrangements in odd and even n-PUR. Both parallel and antiparallel arrangements are feasible for the odd series whereas only the antiparallel arrangement is allowed for the even series. 1372 FERNÁ NDEZ ET AL.Figure 4. Cross polarized light micrographs of 11-PUR (a) and 12-PUR (b) crystallized from the melt at 105 C and 130 C, respectively. 1374 FERNÁ NDEZ ET AL.

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Section: Introductionmentioning

confidence: 99%

Crystallization studies on linear aliphatic n‐polyurethanes

Fernández

Bermúdez

Versteegen

et al. 2009

J Polym Sci B Polym Phys

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“…is high-elasticity, g -gaseous, l -liquid. Table 4 summarizes the standard enthalpy of combustion D c H m , standard molar enthalpy D f H m , entropy D f S m and Gibbs function D f G m of formation of hemiisotactic and stereoblock polypropylenes at T = 298.15 K. For comparison, the results for atactic and isotactic PP, studied earlier [12], are also given. The standard molar enthalpies of formation of the examined polypropylenes were calculated from their D c H m values (table 4), enthalpies of formation of liquid water and gaseous carbon dioxide [16].…”

Section: Resultsmentioning

confidence: 97%

“…The design of the calorimeter was improved at the Research Institute of Chemistry of Nizhny Novgorod State University. The improvements resulted in a substantial increase of the measurement accuracy that were described earlier [6,12]. It should only be noted that the rise of temperature was measured with a platinum resistance thermometer connected in a bridge circuit with a high-sensitive galvanometer as a zero-instrument.…”

Section: Methodsmentioning

confidence: 97%

Standard thermochemical characteristics of formation of hemiisotactic and stereoblock polypropylenes at T=298.15K

Смирнова

Kulagina

Маркин

2009

The Journal of Chemical Thermodynamics

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“…10 Comparing the numerical C p° val ues and characteristics of physical transitions, one can distinguish several specific features. The C p° values for PU {6,6} and polyhexamethyleneurethane in the crystal line and glassy states in the temperature interval from 80 K to T g°, as should be expected, do not differ within the error of determination of C p°.…”

Section: т/к C P°( т ) S°(t ) H°(t ) -H°(0) -[G°(t ) -H°(0)]mentioning

confidence: 99%

Thermodynamic properties of linear polyurethanes based on 1,6-hexamethylenediisocyanate with butane-1,4-diol and hexane-1,6-diol in the temperature range from T → 0 to 460 K

et al. 2006

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The temperature dependences of the heat capacity of partially crystalline linear polyure thanes based on 1,6 hexamethylenediisocyanate with butane 1,4 diol and hexane 1,6 diol were studied for the first time in a temperature range of 6-460 K by the methods of adiabatic vacuum and dynamic calorimetry. Physical changes in the state of polyurethanes were revealed and characterized; the standard thermodynamic functions, namely, C p°( T ), H°(T ) -H°(0), S°(T ), and G°(T ) -H°(0), were calculated from the obtained experimental data in the temperature range from Т → 0 to 460 K for the polymers in the crystalline, glassy, highly elastic, and liquid states. The energies of combustion of the polymers were measured by the bomb calorimetry method, and the standard thermodynamic characteristics of their formation at 298.15 K were calculated. The thermodynamic characteristics of bulk polycondensation of 1,6 hexamethylenediisocyanate with butane 1,4 diol and hexane 1,6 diol to form linear ali phatic polyurethanes {4,6} and {6,6} were determined in the range from Т → 0 to 350 K at р° = 0.1 MPa. The thermodynamic properties of the polyurethanes under study and polymers of isomeric structure were compared.Key words: polyurethanes based on 1,6 hexamethylenediisocyanate with butane 1,4 diol and hexane 1,6 diol, heat capacity, enthalpy, entropy, Gibbs function, calorimetry, thermo dynamics.Polyurethanes (PUs) are among the most significant industrial polymers 1,2 and used for designing new promis ing materials. 3-5In the present time, one of the main methods for industrial production of linear PUs is the reaction of diisocyanates with diols 1 that affords m,n PUs. Many works on studying the thermodynamic and thermal properties of m,n PUs were carried out by calorimetric DTA and DSC methods, 6,7 which are inferior in terms of accuracy and the amount of data obtained to low temperature adiabatic vacuum calorimetry (AVC). Com bined studies by precision AVC methods are necessary to compare the thermodynamic properties of aliphatic polyurethanes, to study dependences of these proper ties on the composition, structure, and physical state, and to prepare related composite materials. These studies have previously 8-10 been performed for linear aliphatic n PUs synthesized by the polymerization of cyclic ure thanes with ring opening and interaction of isocyanato alcohols.The following tasks were given priority in the present work: 1) calorimetric study of temperature dependences of the heat capacity of partially crystalline linear PUs based on 1,6 hexamethylenediisocyanate with butane 1,4 diol (PU {4,6}) and hexane 1,6 diol (PU {6,6}) and deter mination of the thermodynamic characteristics of pos sible physical transformations in the 6-460 K tempera ture range;2) calculation of the standard thermodynamic func tions C p°( T ), H°(T ) -H°(0), S°(T ), and G°(T ) -H°(0) for the temperature range from Т → 0 to 460 K using the obtained data;3) measurement of the energy of combustion of PU {4,6} and PU {6,6}, calculation of the standard ther modynam...

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Thermodynamics of Linear Poly(pentamethylene urethane) and Poly(hexamethylene urethane) in the Range from 0 to 450 K

Cited by 14 publications

References 9 publications

Crystallization studies on linear aliphatic n‐polyurethanes

Crystallization studies on linear aliphatic n‐polyurethanes

Standard thermochemical characteristics of formation of hemiisotactic and stereoblock polypropylenes at T=298.15K

Thermodynamic properties of linear polyurethanes based on 1,6-hexamethylenediisocyanate with butane-1,4-diol and hexane-1,6-diol in the temperature range from T → 0 to 460 K

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