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Phase diagrams of smart copolymers poly(N-isopropylacrylamide) and poly(sodium acrylate).

Zarzyka I, Di Lorenzo ML, Pyda M - ScientificWorldJournal (2014)

Bottom Line: Experiments related to linear polymers (PNIPA and PNIPA-SA) indicated nontypical demixing/mixing behavior with a lower critical solution temperature (LCST), which do not correspond to the three classical types of limiting critical behavior.Some similarities and differences are observed in comparison to our literature data using standard TM-DSC for PNIPA/water.Furthermore no influence of composition cross-linked PNIPA/water system on demixing/mixing temperature was observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Rzeszow University of Technology, 35-959 Rzeszow, Poland.

ABSTRACT
The phase behavior of linear poly(N-isopropylacrylamide) (PNIPA), linear copolymer poly(N-isopropylacrylamide) and poly(sodium acrylate) (PNIPA-SA), and chemically cross-linked PNIPA in water has been determined by temperature modulated differential scanning calorimetry (TM-DSC). Experiments related to linear polymers (PNIPA and PNIPA-SA) indicated nontypical demixing/mixing behavior with a lower critical solution temperature (LCST), which do not correspond to the three classical types of limiting critical behavior. Some similarities and differences are observed in comparison to our literature data using standard TM-DSC for PNIPA/water. Furthermore no influence of composition cross-linked PNIPA/water system on demixing/mixing temperature was observed.

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Phase diagram of linear copolymer PNIPA-SA/water system; onset values of LCST were taken from the TM-DSC (reversing heat flow) plots upon first and second heating at 5°C/min; lines are guides for the eye.
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fig6: Phase diagram of linear copolymer PNIPA-SA/water system; onset values of LCST were taken from the TM-DSC (reversing heat flow) plots upon first and second heating at 5°C/min; lines are guides for the eye.

Mentions: In this paper, the measured values of LCST are plotted in Figures 5, 6, 7, and 8 as function of gel content. Three distinct two-phase areas are observed in case of PNIPA and PNIPA-SA.


Phase diagrams of smart copolymers poly(N-isopropylacrylamide) and poly(sodium acrylate).

Zarzyka I, Di Lorenzo ML, Pyda M - ScientificWorldJournal (2014)

Phase diagram of linear copolymer PNIPA-SA/water system; onset values of LCST were taken from the TM-DSC (reversing heat flow) plots upon first and second heating at 5°C/min; lines are guides for the eye.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4150473&req=5

fig6: Phase diagram of linear copolymer PNIPA-SA/water system; onset values of LCST were taken from the TM-DSC (reversing heat flow) plots upon first and second heating at 5°C/min; lines are guides for the eye.
Mentions: In this paper, the measured values of LCST are plotted in Figures 5, 6, 7, and 8 as function of gel content. Three distinct two-phase areas are observed in case of PNIPA and PNIPA-SA.

Bottom Line: Experiments related to linear polymers (PNIPA and PNIPA-SA) indicated nontypical demixing/mixing behavior with a lower critical solution temperature (LCST), which do not correspond to the three classical types of limiting critical behavior.Some similarities and differences are observed in comparison to our literature data using standard TM-DSC for PNIPA/water.Furthermore no influence of composition cross-linked PNIPA/water system on demixing/mixing temperature was observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Rzeszow University of Technology, 35-959 Rzeszow, Poland.

ABSTRACT
The phase behavior of linear poly(N-isopropylacrylamide) (PNIPA), linear copolymer poly(N-isopropylacrylamide) and poly(sodium acrylate) (PNIPA-SA), and chemically cross-linked PNIPA in water has been determined by temperature modulated differential scanning calorimetry (TM-DSC). Experiments related to linear polymers (PNIPA and PNIPA-SA) indicated nontypical demixing/mixing behavior with a lower critical solution temperature (LCST), which do not correspond to the three classical types of limiting critical behavior. Some similarities and differences are observed in comparison to our literature data using standard TM-DSC for PNIPA/water. Furthermore no influence of composition cross-linked PNIPA/water system on demixing/mixing temperature was observed.

Show MeSH
Related in: MedlinePlus