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Demixing and remixing kinetics of poly(2-isopropyl-2-oxazoline) (PIPOZ) aqueous solutions studied by modulated temperature differential scanning calorimetry

(2010) MACROMOLECULES. 43(16). p.6853-6860
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Abstract
The demixing and remixing kinetics of aqueous solutions of poly(2-isopropyl-2-oxazoline) (PIPOZ) with four different chain lengths (number-average molar mass of 3300-13000 g mol-1) is studied by means ofmodulated temperature differential scanning calorimetry(MTDSC) in both nonisothermal and quasiisothermal modes. The nonisothermal measurements show that the aqueous solutions of all four PIPOZ samples follow the lower critical solution temperature (LCST) phase behavior. Both the LCST and the corresponding polymer weight fraction (fw) decreasewith increasingmolarmass: 33.8 +/- 0.1 degrees C at 29.8 wt % for 3300 g mol-1 shifts to 26.2 ( 0.1 degrees C at 19.8 wt % for 13000 g mol-1. This typical type I phase behavior of aqueous solutions of PIPOZ is in contrast to the typical type II phase behavior of poly(N-isopropylacrylamide) (PNIPAM) which has isomeric repeat units. The demixing and remixing kinetics throughout the phase transition is studied by quasi-isothermal heat capacity measurements. Overall, the response for PIPOZ solutions is markedly faster than for PNIPAM solutions.
Keywords
poly(2-oxazoline), Responsive polymer, smart material, INDUCED PHASE-SEPARATION, COIL-GLOBULE TRANSITION, PRESSURE PERTURBATION CALORIMETRY, ZERO CRITICAL CONCENTRATIONS, POLYMER-WATER INTERACTION, CHAIN SEGMENT MOBILITY, HIGH MOLAR MASSES, POLY(VINYL METHYL-ETHER), POLYDISPERSE POLYMERS, MOLECULAR-DYNAMICS

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Citation

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Chicago
Zhao, Jun, Richard Hoogenboom, Guy Van Assche, and Bruno Van Mele. 2010. “Demixing and Remixing Kinetics of Poly(2-isopropyl-2-oxazoline) (PIPOZ) Aqueous Solutions Studied by Modulated Temperature Differential Scanning Calorimetry.” Macromolecules 43 (16): 6853–6860.
APA
Zhao, Jun, Hoogenboom, R., Van Assche, G., & Van Mele, B. (2010). Demixing and remixing kinetics of poly(2-isopropyl-2-oxazoline) (PIPOZ) aqueous solutions studied by modulated temperature differential scanning calorimetry. MACROMOLECULES, 43(16), 6853–6860.
Vancouver
1.
Zhao J, Hoogenboom R, Van Assche G, Van Mele B. Demixing and remixing kinetics of poly(2-isopropyl-2-oxazoline) (PIPOZ) aqueous solutions studied by modulated temperature differential scanning calorimetry. MACROMOLECULES. 2010;43(16):6853–60.
MLA
Zhao, Jun, Richard Hoogenboom, Guy Van Assche, et al. “Demixing and Remixing Kinetics of Poly(2-isopropyl-2-oxazoline) (PIPOZ) Aqueous Solutions Studied by Modulated Temperature Differential Scanning Calorimetry.” MACROMOLECULES 43.16 (2010): 6853–6860. Print.
@article{1025887,
  abstract     = {The demixing and remixing kinetics of aqueous solutions of poly(2-isopropyl-2-oxazoline) (PIPOZ) with four different chain lengths (number-average molar mass of 3300-13000 g mol-1) is studied by means ofmodulated temperature differential scanning calorimetry(MTDSC) in both nonisothermal and quasiisothermal modes. The nonisothermal measurements show that the aqueous solutions of all four PIPOZ samples follow the lower critical solution temperature (LCST) phase behavior. Both the LCST and the corresponding polymer weight fraction (fw) decreasewith increasingmolarmass: 33.8 +/- 0.1 degrees C at 29.8 wt \% for 3300 g mol-1 shifts to 26.2 ( 0.1 degrees C at 19.8 wt \% for 13000 g mol-1. This typical type I phase behavior of aqueous solutions of PIPOZ is in contrast to the typical type II phase behavior of poly(N-isopropylacrylamide) (PNIPAM) which has isomeric repeat units. The demixing and remixing kinetics throughout the phase transition is studied by quasi-isothermal heat capacity measurements. Overall, the response for PIPOZ solutions is markedly faster than for PNIPAM solutions.},
  author       = {Zhao, Jun and Hoogenboom, Richard and Van Assche, Guy and Van Mele, Bruno},
  issn         = {0024-9297},
  journal      = {MACROMOLECULES},
  language     = {eng},
  number       = {16},
  pages        = {6853--6860},
  title        = {Demixing and remixing kinetics of poly(2-isopropyl-2-oxazoline) (PIPOZ) aqueous solutions studied by modulated temperature differential scanning calorimetry},
  url          = {http://dx.doi.org/10.1021/ma1012368},
  volume       = {43},
  year         = {2010},
}

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