Nature of the physical problem
Two main aspects are to be considered in ultrasonic degrada-
Catalogue number: ACYN tion of polymers in solution:
what is the rate of chain breakage? Program obtainable from: CPC Program Library, Queen's where are the points of breakage located along the polymer University of Belfast, N. Ireland (see application form in chain? this issue).
The study of the degradation process is based on the determination of the molecular weight distribution (polydispersity Computer: IBM 370/15 8; Installation: University of Liege PDIS) and of an average molecular weights (number AMWN or weight AMWW * 5 as a function of the irradiation time.
Program language used: FORTRAN IV We have compared these experimental data with simulated values obtained by computer, for testing different hypotheses High speed storage required: 96 kbytes concerning the rate expression and the breakage model. Some simulation programs have been reported [1-3), No. of bits in a byte: 8 but, so far as we know, have never been published. Our prograin is designed to be very general and the four breakage Overlay structure: none models programmed should cover most of the possible cases.
No. of magnetic tapes required: none
Method of solution
The method used to simulate ultrasonic action on polymers Other peripheralsused: card reader, line printer is quiet simple: we start from the initial molecular weight distribution and we follow during the time, how the number No. of cards in combinedprogram and test deck: 792 ofmolecules of each length is modified by breakage and redistribution of broken segments.
Card punching code: EBCDIC
The program USSI is convenient for testing a large number of rate expression and breakage models.