Advertisement

Dielectric analysis of thermoset cure

  • Stephen D. Senturia
  • Norman F. SheppardJr.
Conference paper
Part of the Advances in Polymer Science book series (POLYMER, volume 80)

Abstract

All dielectric measurements involve the determination of the electrical polarization and conduction properties of a sample subjected to a time-varying electric field. Section 2 addresses dielectric measurement methods, the various instruments and electrodes, and their calibrations. Section 3 examines the microscopic mechanisms giving rise in the observed microscopic dielectric properties, and Section 4 explores in detail the effects of temperature and cure on these properties. Finally, Section 5 contains a selected bibliography of applications of dielectric analysis to the study of thermoset cure.

Keywords

Dielectric Property Loss Factor Electrode Polarization Epoxy Cure Relaxation Time Distribution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Nomenclature

α

extent of conversion

β

distribution parameter

tan δ

bulk material loss tangent

tan δx

experimental loss tangent (equivalent to D)

ε0

permittivity of free space, 8.85×10−14 F/cm

εr

relaxed permittivity (relative to ε0)

εu

unrelaxed permittivity (relative to ε0, equivalent to ε)

ε′

bulk permittivity (relative to ε0)

ε′x

experimental permittivity (relative to ε0)

ε′d

dipole contribution to the relative permittivity

ε

infinite-frequency relative permittivity (equivalent to εu)

ε″

bulk loss factor (relative to ε0)

ε″x

experimental loss factor (relative to ε0)

η

viscosity

μ

dipole moment

ϱ

resistivity (equivalent to 1/σ)

σ

conductivity (equivalent to 1/ϱ)

τd

dipole relaxation time

ϕ

phase difference between voltage and current

ω

angular frequency

Ω

ohms

A

area of parallel plate electrodes

C

equivalent circuit representation of bulk sample capacitance

Cb

blocking-layer capacitance

CL

capacitance of microdielectrometer floating gate

Cx(ω)

experimentally measured sample capacitance

C1

constant in Williams-Landel-Ferry (WLF) equation

C2

constant in Williams-Landel-Ferry (WLF) equation

D

dissipation factor (equivalent to tan δx)

H(ω)

microdielectrometer transfer function

i(t)

time-varying current

I

complex amplitude of i(t)

L

spacing of parallel plate electrodes

Ni

concentration of ith ion

qi

charge of ith ion

Q(t)

time-varying charge

ri

radius of ith ion

R

equivalent circuit representation of bulk sample resistance

Rx(ω)

experimentally measured sample resistance

tb

blocking-layer thickness

Tg

glass transition temperature

ui

mobility of ith ion

v(t)

time-varying voltage

V

complex amplitude of v(t)

Y(ω)

experimentally measured admittance

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

7 References

  1. 1.
    Kienle, R. H., Race, H. H.: The electrical, chemical and physical properties of alkyd resins, Trans. Electrochem. Soc., 65, 87 (1934)Google Scholar
  2. 2.
    Manegold, E., Petzoldt, W.: Die elektrische Leitfähigkeit während der Reaktion von sauren bzw. alkalischen phenol-formaldehyd-Gemischen, Kolloid Z., 95, 59 (1941)Google Scholar
  3. 3.
    Lomakin, B. A., Gussewa, N. J.: Kunststoffe, 29, 145 (1939)Google Scholar
  4. 4.
    Lomakin, B. A., Gussewa, N. J.: Anwendung von Leitfähigkeits-. Viskositäts-und Refraktionsmessungen zum Studium der Harzbildung, Plast. Massi 2, 281 (1937)Google Scholar
  5. 5.
    Fineman, M. N., Puddington, I. E.: Kinetics of cure of resol resins, Ind. Eng. Chemistry, 39, 1288 (1947)Google Scholar
  6. 6.
    Fineman, M. N., Puddington, I. E.: Measurements of cure of some thermosetting resins, Can. J. Res., Sec. B., 25, 101 (1947)Google Scholar
  7. 7.
    Coln, M. C. W., Senturia, S. D.: The application of linear system theory to parametric microsensors, p. 118, Proc. Transducers '85, 1985Google Scholar
  8. 8.
    Mopsik, F. I.: Precision time-domain dielectric spectrometer, Rev. Sci. Instr. 55, 79 (1984)Google Scholar
  9. 9.
    Aukward, J. A., Warfield, R. W.: Monitoring device for investigation of encapsulating resins, Rev. Sci. Inst., 27, 413 (1956)Google Scholar
  10. 10.
    Armstrong, R. J.: Method of laminating employing measuring the electrical impedance of a thermosetting resin, U.S. Patent No. 3,600,247Google Scholar
  11. 11.
    Mouayad, L.: Monitoring of transformer oil using microdielectric sensors, M.S. Thesis, Massachusetts Institute of Technology, 1985, unpublishedGoogle Scholar
  12. 12.
    Lee, H. L.: Optimization of a resin cure sensor, M.S. Thesis, Massachusetts Institute of Technology, 1982, unpublishedGoogle Scholar
  13. 13.
    Senturia, S. D., Garverick, S. L.: Method and apparatus for microdielectrometry, U.S. Patent No. 4,423,371Google Scholar
  14. 14.
    Sheppard, Jr., N. F., Garverick, S. L., Day, D. R., Senturia, S. D.: Microdielectrometry: a new method for in-situ cure monitoring, p. 65, Proc. 26th SAMPE Symposium, 1981Google Scholar
  15. 15.
    Senturia, S. D., Sheppard, Jr., N. F., Lee, H. L., Marshall, S. B.: Cure monitoring and control with combined dielectric/temperature probes, SAMPE J., 19, 22 (1983)Google Scholar
  16. 16.
    Aukward, J. A., Warfield, R. W., Petree, M. C.: Change in electrical resistivity of some high polymers during isothermal polymerization, J. Polym. Sci., 27, 199 (1958)Google Scholar
  17. 17.
    Anonymous: Dielectrics improve control of laminate cure time, Plastics Technology, 15, 19 (1969)Google Scholar
  18. 18.
    Hewlett-Packard Co., Palo Alto, CA: Manual for HP4192A Low-Frequency Impedance AnalyzerGoogle Scholar
  19. 19.
    GenRad Co., Concord MA: Manual for 1689 DigibridgeGoogle Scholar
  20. 20.
    Micromet Instruments, Inc., Cambridge, MA: The Eumetric System II Microdielectrometer, Product Bulletin, 1985Google Scholar
  21. 21.
    McCrum, N. G., Read, B. E., Williams, G.: Anelastic and dielectric effects in polymeric solids, New York, Wiley and Sons 1967Google Scholar
  22. 22.
    Hedvig, P.: Dielectric spectroscopy of polymers, New York, Wiley and Sons 1977Google Scholar
  23. 23.
    Smyth, C. P.: Dielectric behavior and structure, New York, McGraw-Hill 1955Google Scholar
  24. 24.
    Fava, R. A., Horsfield, A. E.: The interpretation of electrical resistivity measurements during epoxy resins cure, Brit. J. Appl. Phys. (J. Phys. D), Ser 2 1, 117 (1968)Google Scholar
  25. 25.
    Lee, H., Neville, K.: Handbook of epoxy resins, New York, McGraw-Hill 1967Google Scholar
  26. 26.
    Wright, W. W.: Characterisation of a Bisphenol-A epoxy resin, Brit. Polym. J., 15, 224 (1983)Google Scholar
  27. 27.
    Bockris, J. O'M., Reddy, A. K. N.: Modern electrochemistry, Volume 1, Section 4.4, New York, Plenum Press 1970Google Scholar
  28. 28.
    Debye, P.: Polar molecules, New York, Chemical Catalog Co. 1929Google Scholar
  29. 29.
    Cole, K. S., Cole, R. H.: Dispersion and absorption in dielectrics I. Alternating current characteristics, J. Chem. Phys., 9, 341 (1941)Google Scholar
  30. 30.
    Davidson, D. W., Cole, R. H.: Dielectric relaxation in glycerine, J. Chem. Phys., 18, 1417 (1950)Google Scholar
  31. 31.
    Williams, G., Watts, D. C.: Non-symmetrical dielectric relaxation behavior arising from a simple empirical decay function, Trans. Farad. Soc., 66, 80 (1970)Google Scholar
  32. 32.
    Williams, G., Watts, D. C., Dev, S. B., North, A. M.: Further considerations of nonsymmetrical dielectric relaxation behavior arising from a simple empirical decay function, Trans. Farad. Soc., 67, 1323 (1971)Google Scholar
  33. 33.
    Lindsey, C. P., Patterson, G. D.: Detailed comparison of the Williams-Watts and Cole-Davidson functions, J. Chem. Phys. 73, 3348 (1980)Google Scholar
  34. 34.
    Moynihan, C. T., Boesch, L. P., Laberge, N. L.: Decay function for the electric field relaxation in vitreous ionic conductors, Phys. Chem. Glasses, 14, 122 (1973)Google Scholar
  35. 35.
    Sheppard, Jr., N. F.: Dielectric analysis of the cure of thermosetting epoxy/amine systems, Ph.D. Thesis, Massachusetts Institute of Technology, 1985, unpublishedGoogle Scholar
  36. 36.
    Johnson, J. F., Cole, R. H.: Dielectric polarization of liquid and solid formic acid, J. Am. Chem. Soc., 73, 4536 (1951)Google Scholar
  37. 37.
    Adamec, V.: Electrical properties of an epoxy resin during and after curing. J. Polym. Sci., 10, 1277 (1972)Google Scholar
  38. 38.
    Day, D. R., Lewis, T. J., Lee, H. L., Senturia, S. D.: The role of boundary layer capacitance at blocking electrodes in the interpretation of dielectric cure data in adhesives, J. Adhesion, 18, 73 (1985)Google Scholar
  39. 39.
    Zukas, W. X., MacKnight, W. J., Schneider, N. S.: Dynamical mechanical and dielectric properties of an epoxy resin during cure, in C. A. May (ed.), Chemorheology of Thermosetting Polymers, ACS Symposium Series, 227, 223 (1983)Google Scholar
  40. 40.
    May, C. A.: Dielectric measurements for composite cure control — two case studies, p. 108, Proc. 20th SAMPE Symp., 1975Google Scholar
  41. 41.
    May, C. A.: Composite cure studies by dielectric and calorimetric analyses, p. 803, Proc. 21st SAMPE Symp., 1976Google Scholar
  42. 42.
    Lawless, G. W.: High temperature dielectric studies of epoxy resin, Polym. Eng. Sci., 20, 546 (1980)Google Scholar
  43. 43.
    Baumgartner, W. E., Ricker, T.: Computer assisted dielectric cure monitoring in material quality and cure process control, SAMPE J., 19, 6 (1983)Google Scholar
  44. 44.
    Bidstrup, W. B., Sheppard, Jr., N. F., Senturia, S. D.: Monitoring of laminate cure with microdielectrometry, SPE Tech. Papers, 31, 324 (1985)Google Scholar
  45. 45.
    Pike, R. A., Douglas, F. C., Wisner, G. R.: Electrical dissipation factor; guide to molding quality graphite/resin composites, Polym. Eng. Sci., 11, 502 (1971)Google Scholar
  46. 46.
    Sheppard, Jr., N. F., Senturia, S. D.: WLF dependence of the dielectric properties of DGEBA epoxy resins, J. Polym. Sci., Polym. Phys. Ed., submitted for publicationGoogle Scholar
  47. 47.
    Sheppard, Jr., N. F., Coln, M. C. W., Senturia, S. D.: A dielectric study of the time-temperature-transformation (TTT) diagram of DGEBA epoxy resins cured with DDS, p. 1243, Proc. 29th SAMPE Symp., 1984Google Scholar
  48. 48.
    Huguenin, F. G. A. E., Klein, M. T.: Intrinsic and transport-limited epoxy-amine cure kinetics, Ind. Eng. Chem. Prod. Res. Dev., 24, 166 (1985)Google Scholar
  49. 49.
    Shito, N., Sato, M.: Electrical and mechanical properties of anhydride-cured epoxy resins, J. Polym. Sci. Part C, 16, 1069 (1967)Google Scholar
  50. 50.
    Shito, M.: Specific volume, dielectric properties, and mechanical properties of cured epoxy resins in the glass-transition region, J. Polym. Sci. Part C, 23, 569 (1968)Google Scholar
  51. 51.
    Blyakhman, Ye. M., Borisova, T. I., Levitskaya, Ts. M.: Dielectric relaxation in epoxide resins hardened with different anhydrides, Polym. Sci. USSR, 12, 1756 (1970)Google Scholar
  52. 52.
    Blyakhman, Ye. M., Borisova, T. I., Levitskaya, Ts. M.: Molecular mobility study on set epoxy resins of different molecular weights, using the dielectric method, Polym. Sci. USSR, 12, 2602 (1970)Google Scholar
  53. 53.
    Williams, M. L., Landel, R. F., Ferry, J. D.: The temperature dependence of relaxation mechanisms in amorphous polymers and other glass-forming liquids, J. Am. Chem. Soc., 77, 3701 (1955)Google Scholar
  54. 54.
    Sheppard, Jr., N. F., Day, D. R., Lee, H. L., Senturia, S. D.: Microdielectrometry, Sensors & Actuators, 2, 263 (1982)Google Scholar
  55. 55.
    Delmonte, J.: Electrical properties of epoxy resins during polymerization, J. Appl. Polym. Sci., 2, 108 (1959)Google Scholar
  56. 56.
    Olyphant, Jr., M.: Effect of cure and aging on dielectric properties, Suppl. p. 12, Proc. 6th IEEE Electrical Insulation Conf., 1965Google Scholar
  57. 57.
    Warfield, R. W., Petree, M. C.: The use of electrical resistivity in the study of the polymerization of thermosetting polymers, J. Polym. Sci., 37, 305 (1959)Google Scholar
  58. 58.
    Warfield, R. W., Petree, M. C.: A study of the polymerization of epoxide polymers by electrical resistivity techniques, Polymer, 1, 178 (1960)Google Scholar
  59. 59.
    Kagan, G. T., Moshinskii, L. Ya., Nesolyonaya, L. G., Marina, D. I., Romantsevich, M. K.: Study of kinetics of setting of epoxide resins with anhydrides, Vysokomol. Soedin., A10, 62 (1968)Google Scholar
  60. 60.
    Acitelli, M. A., Prime, R. B., Sacher, E.: Kinetic of epoxy cure: (1) the system Bisphenol-A diglycidyl ether/m-phenylenediamine, Polymer, 12, 335 (1971)Google Scholar
  61. 61.
    Prime, R. B.: Thermosets, in Edith Turi (ed.), Thermal Characterization of Polymeric Materials, New York, Academic Press 1981Google Scholar
  62. 62.
    Schechter, L., Wynstra, J., Kurkjy, R. P.: Glycidyl ether reactions with amines, Ind. Eng. Chem., 48, 94 (1956)Google Scholar
  63. 63.
    Sourour, S., Kamal, M. R.: Differential scanning calorimetry of epoxy cure: isothermal cure kinetics, Thermochimica Acta, 14, 41 (1976)Google Scholar
  64. 64.
    Judd, N. C. W.: Investigation of the polymerization of an unsaturated polyester system by a resistivity technique, J. Appl. Polym. Sci., 9, 1743 (1965)Google Scholar
  65. 65.
    Learmonth, G. S., Pritchard, G.: Electrical resistivity and crosslinking in thermosetting resins, Ind. Eng. Chem. Prod. Prod. Res. Dev., 8, 124 (1969)Google Scholar
  66. 66.
    Fisch, W., Hofmann, W.: Chemischer Aufbau von gehärteten Epoxydharzen, Makromol. Chem., 44, 8 (1961)Google Scholar
  67. 67.
    Huraux, C., Sellaimia, A.: Variation des proprietes dielectriques accompagnant le durcissement de resines epoxydes, C.R. Acad. Sc. Paris, 277, Serie B, 497 (1973)Google Scholar
  68. 68.
    Huraux, C., Sellaimia, A.: Sur la variation des proprieties dielectriques et la cinetique du durcissement de resines epoxides, C.R. Acad. Sc. Paris 277, Serie B, 691 (1973)Google Scholar
  69. 69.
    Dandurant, D., Huraux, C.: Etude de mecanisme de durcissement de resines au moyen de spectres de relaxation dielectrique, Prace Naukowe Instytutu Podstaw Elektrotechniki i Electrotechnologii Politechniki Wrocleawskiej, 16, 275 (1977)Google Scholar
  70. 70.
    Soualmia, A., Huraux, C., Despax, B.: Relation entre les parametres dielectriques et la cinetique de reaction de polymerisation en phase liquide, Makromol. Chem., 183, 1803 (1982)Google Scholar
  71. 71.
    Sheppard, Jr., N. F., Senturia, S. D.: Chemical interpretation of the relaxed permittivity during epoxy resin cure, SPE Tech. Papers, 31, 321 (1985)Google Scholar
  72. 72.
    Williams, G.: Dielectric information on chain mobility, chain configuration, and an order-disorder transition in amorphous poly(acetaldehyde), Trans. Farad. Soc., 59, 1397 (1962)Google Scholar
  73. 73.
    Sheppard, J., N. F., Senturia, S. D.: Molecular contributions to the dielectric permittivity of unreacted epoxy/amine mixtures, p. 22a, Technical Program Summary, Adhesion Society Annual Meeting, Savannah, GA, 1985Google Scholar
  74. 74.
    Lane, J. W., Bachmann, M. S., Seferis, J. C.: Monitoring of matrix property changes during composite processing, SPE Tech. Papers, 31, 318 (1985)Google Scholar
  75. 75.
    Lane, J. W., Bachmann, M. S., Seferis, J. C.: Dielectric Studies of the cure of epoxy matrix systems, J. Appl. Polym. Sci., in pressGoogle Scholar
  76. 76.
    Tajima, Y. A., Crozier, D.: Thermokinetic modeling of an epoxy resin I. Chemoviscosity, Polym. Eng. Sci., 23, 186 (1983)Google Scholar
  77. 77.
    Apicella, A., Nicolais, L., Nobile, M. R., Castiglione-Morelli, M. A.: Effect of processing variables on the durability of epoxy resins for composite systems, Comp. Sci. Tech., in pressGoogle Scholar
  78. 78.
    Enns, J. B., Gillham, J. K.: Time-temperature-transformation (TTT) cure diagram: modeling the cure behavior of thermosets, J. Appl. Polym. Sci., 28, 2567 (1983)Google Scholar
  79. 79.
    Zukas, W. X., Schneider, N. S., MacKnight, W. J.: Dielectric and dynamic mechanical monitoring of epoxy resin cure, Polym. Prepr., 25 (2), 205 (1984)Google Scholar
  80. 80.
    Daly, J., Pethrick, R. A.: Rubber-modified epoxy resins: 2. Dielctric and ultrasonic relaxation studies, Polymer, 22, 37 (1981)Google Scholar
  81. 81.
    Sacher, E.: The DC conductivity of polyimide film, p. 33, Proc. IEEE Conf. on Elec. Ins. Dielec. Phen., 1976Google Scholar
  82. 82.
    Carpenter, J. F.: Instrumental techniques for developing epoxy cure cycles, p. 783, Proc. 21st SAMPE Symposium, 1976Google Scholar
  83. 83.
    Tajima, Y. A.: Monitoring cure viscosity of epoxy composite, Polym. Comp., 3, 162 (1982)Google Scholar
  84. 84.
    Kranbuehl, D. E.: Dynamic dielectric characterization of thermosets and thermoplastics using intrinsic cariables, p. 1251, Proc. 29th SAMPE Symp., 1984Google Scholar
  85. 85.
    Kranbuehl, D. E., Delos, S., Yi, E., Mayer, J., Hou, T., Winfree, W.: Correlation of dynamic dielectric measurements with viscosity in polymeric resin systems, p. 638, Proc. 30th SAMPE Symp., 1985Google Scholar
  86. 86.
    McGowan, E. J., Mathes, K. N.: Measurement of cure in casting resins by means of electrical properties, p. 17, Proc. IEEE Conf. on Elec. Insul., 1962Google Scholar
  87. 87.
    Adabbo, H. E., Williams, R. J. J.: The evolution of thermosetting polymers in a conversion-temperature phase diagram, J. Appl. Polym. Sci. 27, 1327 (1982)Google Scholar
  88. 88.
    Armstrong, R. J.: Laminating control system, Solid State Technology, p. 50, Nov. 1969Google Scholar
  89. 89.
    Kim, D. H.: Application of the dielectric analysis to polymeric materials control, Proc. TTCP-3 Critical Review; Techniques for the Characterization of Polymeric Materials, AMMRC MS 77-2, AD-36082, 1977Google Scholar
  90. 90.
    Dixon, R. R.: Measuring moisture by dielectric analysis, SPE Tech. Papers, 25, 835 (1979)Google Scholar
  91. 91.
    May, C. A., Hadad, D. K., Browning, C. E.: Physiochemical quality assurance methods for composite matrix resins, Polym. Eng. Sci., 19, 545 (1979)Google Scholar
  92. 92.
    Standish, J. V., Leidheiser, Jr., H.: The effect of water on the dielectric properties of a corrosion-protective epoxy-polyamide coating, ACS Div. Org. Coat. Plast. Chem. Prepr. 43, 565 (1980)Google Scholar
  93. 93.
    Day, D. R.: Effects of stoichiometric mixing ratio on epoxy cure — dielectric analysis, SPE Tech. Papers, 31, 327 (1985)Google Scholar
  94. 94.
    Senturia, S. D., Sheppard, Jr., N. F., Lee, H. L., Day, D. R.: In-situ measurement of the properties of curing systems with microdielectrometry, J. Adhesion, 15, 69 (1982)Google Scholar
  95. 95.
    May, C. A., Dusi, M. R., Fritzen, J. S., Hadad, D. K., Maximovich, M. G., Thrasher, K. G., Wereta, Jr., A.: A rheological and chemical overview of thermoset curing, in C. A. May (ed.), Chemorheology of Thermosetting Polymers, ACS Symposium Series 227, 1 (1983)Google Scholar
  96. 96.
    Chottiner, J., Sanjana, Z. N., Kodani, M. R., Lengel, K. W., Rosenblatt, G. B.: Monitoring cure of large autoclave molded parts by dielectric analysis, p. 77, Proc. 26th SAMPE Symp., 1981Google Scholar
  97. 97.
    Sanjana, Z. N., Selby, R. L.: Monitoring cure of epoxy resins using a microdielectrometer, p. 1233, Proc. 29th SAMPE Symp., 1984Google Scholar
  98. 98.
    Allen, J. D.: In-process dielectric monitoring of polymeric resin cure, p. 270, Proc. 20th SAMPE Symp., 1975Google Scholar
  99. 99.
    Crabtree, D. J.: Ion graphing as an in-process cure monitoring procedure for composite and adhesively bonded structures, p. 636, Proc. 22nd SAMPE Symp., 1977Google Scholar
  100. 100.
    Sanjana, Z. N., Schaefer, W. H., Ray, J. R.: Effect of aging and moisture on the reactivity of a graphite epoxy prepreg, Polym. Eng. Sci., 21, 474 (1981)Google Scholar
  101. 101.
    Wereta, Jr., A., May, C. A.: Dielectric monitoring of the bonding process, J. Adhesion, 12, 317 (1981)Google Scholar
  102. 102.
    Pike, R. A., Lamm, F. P., Pinto, J. P.: Factors affecting the processing of epoxy film adhesives: 1. Room temperature aging, J. Adhesion, 12, 143 (1981)Google Scholar
  103. 103.
    La Mantia, F. P., Schifani, R., Acierno, D.: Effect of a filler on the dielectrid properties of an an epoxy resin, J. Appl. Polym. Sci., 28, 3075 (1983)Google Scholar
  104. 104.
    Delmonte, J.: Electrical properties of modified epoxy resins, Modern Plastics, 35, 152 (1958)Google Scholar
  105. 105.
    Sanjana, Z. N., Selby, R. L.: The use of dielectric analysis to study the cure of a filled epoxy resin, IEEE Trans. Elec. Ins., 16, 496 (1981)Google Scholar
  106. 106.
    Pais, J. C., Griffiths, V. S.: The effect of chemical bonding on current flow in thermosetting polymers, p. 5, Proc. IEEE Conf. on Elec. Insul. and Dielec. Phen., 1968Google Scholar
  107. 107.
    Learmonth, G. S., Tomlinson, F. M., Czerski, J.: Cure of polyester resins, I., J. Appl. Polym. Sci., 12, 403 (1968)Google Scholar
  108. 108.
    Learmonth, G. S., Pritchard, G.: Dielectric relaxation and crosslinking in unsaturated polyester resins, J. Appl. Polym. Sci., 13, 1219 (1969)Google Scholar
  109. 109.
    Van Beek, L. K. H.: Dielectric behavior of curing phenolic-formaldehyde resins, J. Appl. Polym. Sci., 8, 2843 (1964)Google Scholar
  110. 110.
    Sanjana, Z. N.: A study of wire enamel cure using dielectric analysis, Proc. IEEE Conf. Electr. and Electronic Insul., 15, 150 (1981)Google Scholar
  111. 111.
    Kranbuehl, D. E., Delos, S., Jue, P. K.: Dynamic dielectric characterization of the cure process: LARC-160 SAMPE J., 19, 18 (1983)Google Scholar
  112. 112.
    Kranbuehl, D. E., Delos, S., Yi, E.: Ynamic dielctric analysis: nondestructive material evaluation and cure cycle monitoring, SPE Tech. Papers, 31, 311 (1985)Google Scholar
  113. 113.
    Krishna, J. G., Josylu, O. S., Sobhanadri, J., Subrahmaniam, R.: Dielectric behavior of isocyanate-terminated polymers, J. Phys. D: Appl. Phys. 15, 2315 (1982)Google Scholar
  114. 114.
    Goswami, D. N.: The dielectric behavior of natural resin shellac, J. Appl. Polym. Sci., 23, 529 (1979)Google Scholar
  115. 115.
    Khastgir, D., Ghoshal, P. K., Das, C. K.: Dielectric behavior and sulphur vulcanization of the crosslinked butyl (XL-50) rubber, Polymer, 24, 617 (1983)Google Scholar
  116. 116.
    Hinkley, J. A.: Monitoring of a rubber cure by microdielectrometry, U. S. Naval Research Lab Memorandum Report 5300, March 30, 1984Google Scholar
  117. 117.
    Wereta, Jr., A., May, C. A.: Dielectric cure investigation of acetylene terminated oligomers, ACS Div. Org. Coat. Plast. Chem. Prepr., 38, 679 (1978)Google Scholar
  118. 118.
    Sanjana, Z. N.: Overage indicators for prepreg products, SAMPE J., 16, 5 (1980)Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Stephen D. Senturia
    • 1
  • Norman F. SheppardJr.
    • 1
  1. 1.Massachusetts Institute of TechnologyCambridgeUSA

Personalised recommendations