Temperature-Modulated DSC

Transcription

1 Netsu Sokutei Temperature-Modulated DSC Akihiko Toda (Received October 17, 2001; Accepted December 10, 2001) The method of temperature-modulated DSC is reviewed in terms of its applicability and valuable characteristics. This method is frequently employed as a convenient tool for the measurement of heat capacity and its relaxation phenomena. T-M DSC can differentiate processes sensitive to temperature modulation, and hence the application is also valuable for the separation of different processes taking place simultaneously and for the examination of kinetics of phase transitions and chemical reactions. 90 DSCT-M DSCDSC 1-7) DSC DSC reversing heat flow RHF total heat flow THFTHF DSC T-M DSC DSC T-M DSCTHF RHF non-reversing heat flownrhf NRHF THF RHF DSC60 Fig.1 2 physical ageing vitrificationconstrained amorphous phase1 T-M DSC 8) T-M DSCFig The Japan Society of Calorimetry and Thermal Analysis. 21

2 number of papers year Fig.1 Number of papers applying T-M DSC in the field of physical and chemical sciences. T / C0 / mj K 1 ϕ / deg R φ / deg Fig.3 Plots of calibration coefficient, R, against phase angle, ϕ, on a master curve for the modulation period of 28 s. Purge gases are He and N 2. Fig.2 (c) (d) (e) t / s T-M DSC results for the reaction process of an epoxy-amin system at β 2.0 K min 1, T s 0.4 K and period 80 s. T s QFig.2 C 0e i ϕ Figs.2(c) and (d) T s βt Re[ T s e i (ω t ε ) ] (1) Q Q Re[ Qe i (ω t δ ) ] (2) Qe i (ω t δ ) C 0e i ϕ d Ts e i (ω t ε ) (3) dt C 0e i ϕ ( Q / ω Ts )e i (ε δ π ) 2 (4) DSC ϕ 9) 10) R C s / C 0 ϕ 1 Fig.3 C s 11) ω 0 ( ) C s 2 C 0 1 Aω 2 (5) Ce i α C ' i C " 11) C RHF β C RHFTHF Q NRHFTHF RHFFig.2(e)Fig.2 RHF RHFTHF NRHF DSC ) 22

3 DSC Q e i (ω t δ ) in mw tan α Ts e i (ω t ε ) in K T / Fig.4 Typical examples of Lissajous diagram of modulated heat flow and sample temperature in the melting region of PET crystals. Fig.5 T-M DSC results in the glass transition of amorphous PET at β 1.0 K min 1 and period 40 s. 1 T-M DSC1 Fig ) β 1 1 β heating only heating only (4) 16) C / mj K 1 t / min Fig.6 Plots of the time sequence of the apparent heat capacity (thick line) overlapped with the exothermic heat flow (thin line) of polyethylene crystallization under quasi-isothermal condition of T s127.5 with T s0.2 K and period 52 s. DSC Fig.5 RHF DSC 17) DSC THF DSC RHF NRHF 23

4 Fig.7 C ' Schematic Cole-Cole plot of the apparent heat capacity in transition regions. DSC Fig.6 18) 19,20) X 21) fold 1 1 DSC RHF RHF Reversing Reversing τω Fig.7 τ ωτ 1 Fig.8 90 F' T 1/ω 18) F' T Te i ω t C s d Te i ω t dt i (C s F ' T) ω T / Plots of THF (thick line) and RHF (thin lines) in the melting region of ice trapped in pores and nylon 6 crystals. d Te i ω t (6) dt 1/ω τ ωτ 1 26) RHF THF RHFTHF Fig.8 RHF ( ωτ 0) THF (7) NRHF ( ωτ 0) 0 (8) 24

5 DSC ( C 'Cs) / ( Fmelt /β ) C / mj K 1 C " / ( Fmelt /β ) t / s Fig.9 Quasi-isothermal measurement for the reaction process of an epoxy-amin system with period 80 s and T s 0.2 K. τ Fig.7 24) 23 C " THF F E ω C " E RT 2 (9) F Kissinger plot 22) 18) 1/ω RHF Fig.2(c)- (e) RHF THF NRHF Fig.9 23) RHF THF F exo RHFωτ0THF F exo NRHF Fig.8 24) NRHF ( ωτ 0) F exo (10) RHFTHF, DSCRHFTHF 27) Fig.10β τ ( β ) 24) Ce i α C s F /β 1 iωτ ( β ) log(ω) Fig.10 Frequency and heating rate dependences of the real and imaginary parts of the apparent heat capacity at the peak temperature in the melting region of polyethylene crystals under heating only condition. β 0.2 (), 0.4 (), 0.8 () and 1.6 K min 1 (). (11) β τ β 25

6 τ β R T 24) τ β x R T x /(1x) (12) x 0.51 x 0.5 T x 1.0 log R T T-M DSC T-M DSC DSC 1) P. S. Gill, S. R. Sauerbrunn, and M. Reading, J. Therm. Anal. 40, 931 (1993). 2) M. Reading, D. Elliott, and V. L. Hill, J. Therm. Anal. 40, 949 (1993). 3) M. Reading, A. Luget, and R. Wilson, Thermochim. Acta 238, 295 (1994). 4) B. Wunderlich, Y. Jin, and A. Boller, Thermochim. Acta 238, 277 (1994). 5) A. Boller, Y. Jin, and B. Wunderlich, J. Therm. Anal. 42, 307 (1994). 6) I. Hatta, Jpn. J. Appl. Phys. 33, L686 (1994). 7), Thermochim. Acta 304/305 (1997); J. Therm. Anal. 54 (1998); Thermochim. Acta 330 (1999). 8) 22, 82 (1995). 9) T. Ozawa and K. Kanari, Thermochim. Acta 288, 39 (1996). 10) I. Hatta and S. Muramatsu, Jpn. J. Appl. Phys. 35, L858 (1996). 11) A. Toda, T. Arita, C. Tomita and M. Hikosaka, Polymer 41, 8941 (2000). 12) M. Nishikawa and Y. Saruyama, Thermochim. Acta 267, 75 (1995). 13) I. Hatta, H. Ichikawa, and M. Todoki, Thermochim. Acta 267, 83 (1995). 14) K. Ishikiriyama, A. Boller and B. Wunderlich, J. Therm. Anal. 50, 547 (1997). 15) J. Pak and B. Wunderlich, J. Polym Sci. B38, 2810 (2000). 16) I. Hatta and A. A. Minakov, Thermochim. Acta 330, 39 (1999). 17) A. Hensel, J. Dobbertin, J. E. K. Schawe, A. Boller, and C. Schick, J. Therm. Anal. 46, 935 (1996). 18) A. Toda, T. Oda, M. Hikosaka, and Y. Saruyama, Polymer 38, 231 (1997). 19) I. Okazaki and B. Wunderlich, Macromolecules 30, 1758 (1997). 20) K. Ishikiriyama and B. Wunderlich, Macromolecules 30, 4126 (1997). 21) B. Goderis, H. Reynaers, R. Scherrenberg, V. B. F. Mathot, and M. H. J. Koch, Macromolecules 34, 1779 (2001),. 22) A. Toda, T. Arita, and M. Hikosaka, J. Therm. Anal. Calor. 60, 821 (2000). 23) G. Van Assche, A. Van Hemelrijck, H. Rahier, and B. Van Mele, Thermochim. Acta 268, 121 (1995). 24) A. Toda, C. Tomita, M. Hikosaka, and Y. Saruyama, Polymer 39, 5093 (1998). 25), 26, 161 (1999). 26) K. Kanari and T. Ozawa, J. Therm. Anal. 49, 979 (1997). 27) W. Chen, A. Toda, I. K. Moon, and B. Wunderlich, J. Polym. Sci. B37, 1539 (1999). DSCT-M DSC DSC T-M DSC 1 Akihiko Toda, Faculty of Integrated Arts and Sciences, Hiroshima Univ., TEL , FAX , atoda@hiroshima-u. ac.jp 26