Investigations of the phenomena of coacervation

Turska, E.; Utracki, L. A.

doi:10.1002/app.1959.070020407

Cited by 7 publications

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References 14 publications

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“…In the first case, changes in the intensity of light depolarized by the sample undergoing crystallization was recorded by means of a suitable measuring system. That technique had been shown in our previous work to make possible the determination of crystallization kinetics as an independent process, uncontrolled by the diffusion of the swelling agent inside the sample [8]. I t should be added that the above technique is valid for sufficiently thin samples and for temperatures higher than the glass transition temperature characteristic of the polymer-swelling agent system studied.…”

Section: Ecperimenta1mentioning

confidence: 99%

Microscopic investigations of the liquid‐induced crystallization of the system bisphenol a polycarbonate/carbon tetrachloride

Turska

Benecki

1979

Acta Polymerica

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The rate of growth of spherulites and the kinetics of crystallization OI a carbon tetrachloride-swollen Bisphenol A polycarbonate were determined in the temperature range from 308 K to 343 K by means of an optical microscope.The optical nature of the forming spherulites was investigated. Changes of the final degree of swelling with temperature were determined gravimetrically. Mikroskopische Untersuchung der flussigkeits-induzierten Kristallisation des Systems Polycarbonat (Bisphenol A ) / TetrachlormethylenMit Hilfe der optischen Mikroskopie wurden im Temperaturbereich von 308 K bis 343 K die Geschwindigkeit des Sphiirolithwachstums und die Kristallisationskinetik des in CCI, gequollenen Polycarbonats aus Bisphenol A bastimmt. Der optische Charakter der gebildeten Spharolithe wurde untersucht. Die Temperaturabhangigkeit des Endquellungsgades wurde gravimetrisch bestimmt. ((aHHOn x p u c m a a u a a y u u cuemeabz nosuxap6onam (Guc@enon A) lmempaxnopwemuneIc c@eponmoB H KHHeTma KpHcTannmaI[m ~a6yxmero B CCn, n o n m~a p 6 0~a r a Ha ocHoBe 6xc@eHona A. Hccnepo-(: IIOMOIIJbH, OIITHqeCKOm MHKPOCKOIIHH OIIpeAeJIRJIaCb B o6nac~a Te?EIIepaTyp OT 308 A0 343 CKOpOCTh pOCTa BaJIaCb OIITHYeCHaH IIpHpOAa 06pa30BaHHbIX C@ePOnMTOB. rpaBHMeTpH9eCHHM MeTOAOM OIIpeAenRJIaCb TeMIIepaTyp-H a R SaBXCMMOCTb HOHeYHOa CTeIIeHH ~a 6 y x a~~~. Muxpocxonuuecxoe uccaedosame ~uaxoCmFLo-U~ayyUPO

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Section: Ecperimenta1mentioning

confidence: 99%

Microscopic investigations of the liquid‐induced crystallization of the system bisphenol a polycarbonate/carbon tetrachloride

Turska

Benecki

1979

Acta Polymerica

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Investigations of the phenomena of coacervation. Part II. Coacervation of polyethylene terephthalate

Turska

Utracki

1962

J of Applied Polymer Sci

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Investigations are reported for the influence of temperature, initial polymer concentration, and solvent composition on the course and character of the phenomenon of a division into two liquid phases of the system polyethylene terephthalate–phenol–tetrachloroethane–n‐heptane. Some curves presented show changes in volumes of the phases in polymer content in phases, and in binodials of the liquid phases (Gibbs triangles). The term “coacervate” is suggested for the phase in which concentration of polymers during titration with nonsolvent is greater than that in the balancing phase, and in which at the same time the polymer content changes from 0 to 100%. It is shown that such a division into two liquid phases can take place only when the straight line representing the changes of nonsolvent content intersects the binodial between the critical point of miscibility and the side of the triangle of Gibbs corresponding to the zero content of polymer.

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Investigations of the phenomena of coacervation. Part III. Phase equilibrium in the three‐component system toluene–ethanol–polystyrene

Utracki

1962

J of Applied Polymer Sci

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Parts I and I1 of this work1r2 presented the results of investigations of the phase changes of systems known in the literature as capable of forming coacervates or those we considered as such. The complete regularity with whichdepending on the temperature, the composition of the solvent, and the concentration of the polymerthere appeared the two types of separation that we denoted as coacervation and demixing, as well as the possibility of giving a logical and thorough explanation of the phenomenon made us assume that coacervation is one of the phenomena of phase separation and can be expressed by means of known thermodynamic laws. The aim set for this work is to test the above assumption. THEORETICAL TREATMENTThe theoretical conditions of phase equilibrium for nonelectrolyte solutions have been given by Tompa3 and Scott4 and for electrolytes by Voorn.b From the binodial and the critical points of miscibility and through comparison with experimental results obtained by Dobry,lS Bamford and Tompa6 tried to prove the coincidence of the investigated phenomenon with simple phase separation. However, the theoretical results did not quite agree with the experimental data. I n the author's opinion, therefore, the coincidence between the phase separation determined by the thermodynamic conditions and coacervate separation has not up to now been proved. The main reason for the divergence will probably be the fact that the expression for the thermodynamic potential of mixing is not sufficiently precise.Maron' in his publication of 1959 gave an equation for the thermodynamic potential of mixing for a two-component system. I n further works8 it was shown that the values calculated on the basis of the given theory agreed very well over the entire concentration range with those obtained experimentally.Generalizing Maron's expression for the thermodynamic potential of mixing AG, and applying it to an n-component system, we obtain:Here, nt denotes the mole fraction of component i; vt is the volume fraction of component i; V o and V are the volumes of components of the system before and after mixing, respectively; ci and roi are coefficients of effective volume of component i in the pure liquid state and in solution, respectively; xtj is the coefficient of molecular interactioh between components i and j; and mi is the ratio of molar volumes of pure component i and solvent .If eq. (1) is used to calculate the conditions of the phase equilibrium in a three-component system, the parametric equation of the binodial will be given by eqs. (2) : 399

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Investigations of the phenomena of coacervation

Cited by 7 publications

References 14 publications

Microscopic investigations of the liquid‐induced crystallization of the system bisphenol a polycarbonate/carbon tetrachloride

Microscopic investigations of the liquid‐induced crystallization of the system bisphenol a polycarbonate/carbon tetrachloride

Investigations of the phenomena of coacervation. Part II. Coacervation of polyethylene terephthalate

Investigations of the phenomena of coacervation. Part III. Phase equilibrium in the three‐component system toluene–ethanol–polystyrene

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