HEPHESTUS: An expert system in PROLOG for the interpretation of pyrolysis mass spectra of polyesters, polyethers and polyureas

Abstract Georgakopoulos, C.G., Statheropoulos, M., Kontoyannakos, J. and Parissakis, G., 1993. HEPHESTUS: an expert system in PROLOG for the interpretation of pyrolysis mass spectra of polyesters, polyethers and polyureas. Chemometrics and Intelligent Laboratory Systems, 19: 75–85. The construction of an expert system (ES), called HEPHESTUS, was implemented in a PROLOG environment, for the interpretation of pyrolysis mass spectra (PyMS) of three categories of polymers: polyesters, polyethers and polyureas. The ES can be applied in electron ionization, chemical ionization and desorption chemical ionization PyMS spectra. The knowledge of the domain is organized in the form of rules that relate polymer structures with mass spectra characteristics. This methodology uses mainly the following type of information: presence of repeating units, cyclic oligomers, mass markers, mass fragments and various mass series. The IF part of the rules tests for matching the information extracted from the unknown PyMS spectra with those of the knowledge base. The knowledge base is organized as dendrite, i.e. the polymer structures are organized hierarchically as a tree. Examples of the interpretation rules used are described together with examples of searching and reasoning. The system was evaluated for both spectra that belong to the above three categories and for other spectra. The ability of the system to interpret PyMS spectra of the three categories of polymers is demonstrated and discussed.

[1]  Peter de B. Harrington,et al.  Multivariate rule building expert system , 1990 .

[2]  D. L. Pope,et al.  6 – NUMERICAL TECHNIQUES FOR PROCESSING PYROLYSIS MASS SPECTRAL DATA , 1984 .

[3]  E. Scamporrino,et al.  The effect of ammonium polyphosphate on the mechanism of thermal degradation of polyureas , 1983 .

[4]  Multivariate analysis of time-resolved mass spectral data , 1986 .

[5]  D. Garozzo,et al.  Analytical degradation: An approach to the structural analysis of microbial polyesters by different methods , 1989 .

[6]  W. Windig,et al.  Pyrolysis-mass spectrometry correlations of crosslink density in natural rubber vulcanizates , 1985 .

[7]  A. Liguori,et al.  Characterization of poly(carboxypiperazine) by mass analyzed ion kinetic energy spectrometry , 1982 .

[8]  E. Scamporrino,et al.  Thermal degradation of aromatic-aliphatic polyethers. 1. Direct pyrolysis-mass spectrometry , 1986 .

[9]  W. Windig,et al.  Interpretation of sets of pyrolysis mass spectra by discriminant analysis and graphical rotation , 1983 .

[10]  P. Willett.  A review of chemical structure retrieval systems , 1987 .

[11]  W. J. Irwin.  Analytical pyrolysis - an overview , 1979 .

[12]  Robert P. Lattimer,et al.  Applications of mass spectrometry to polymers , 1984 .

[13]  E. Scamporrino,et al.  Thermal degradation of aromatic-aliphatic polyethers. 2. Flash pyrolysis-gas chromatography-mass spectrometry , 1986 .

[14]  Peter de B. Harrington,et al.  A rule-building expert system for classification of mass spectra , 1989 .

[15]  D. Garozzo,et al.  Identification of the ions produced by fast atom bombardment mass spectrometry in some polyesters and polyamides , 1987 .

[16]  G. Montaudo,et al.  Thermal Degradation Mechanisms in Condensation Polymers , 1987 .

[17]  S. Foti,et al.  Direct mass spectrometry of polymers. X. Primary thermal fragmentation processes in totally aromatic polyesters , 1984 .

[18]  H. Meuzelaar,et al.  Determination of additives in biomer and lycra spandex by pyrolysis tandem mass spectrometry and time temperature resolved pyrolysis mass spectrometry , 1990 .

[19]  H. Düssel,et al.  Field ionization and electron impact mass spectrometry of polymers and copolymers, 4. Aromatic polyethers. , 1975 .

[20]  Douglas B. Lenat.  Computer Software for Intelligent Systems. , 1984 .

[21]  Gerard J. Kleywegt,et al.  PROLOG for Chemists. Part 1 , 1988 .

[22]  Gerard J. Kleywegt,et al.  PROLOG for chemists. Part 2 , 1989 .

[23]  D. Garozzo,et al.  Primary thermal fragmentation processes in poly(lactic acid) investigated by positive and negative chemical ionization mass spectrometry , 1986 .

[24]  D. Garozzo,et al.  Analysis of polymers by mass spectrometry metastable mapping of transitions from pyrolysis products of an aromatic polyamide , 1987 .

[25]  D. Garozzo,et al.  Primary thermal decomposition processes in aliphatic polyesters investigated by chemical ionization mass spectrometry , 1986 .