Device and methods for determination of molecular weight distributions of polymers and distributions of other polymer properties without physical separation

Patent metadata

Field	Value
Publication number	US-11940384-B2
Application number	US-202217951721-A
Country	US
Kind code	B2
Filing date	Sep 23, 2022
Priority date	Apr 21, 2016
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

Devices and methods for determining the cumulative distribution of a polymer property in a reactor without physical separation of reaction subcomponents. The device includes a means of measuring an instantaneous property of the polymers being produced in a reaction vessel a plurality of times during a polymerization reaction as well as a means of determining the corresponding change in polymer concentration in the reaction vessel between measurements of the instantaneous polymer property. The device also includes a means of computing a statistical distribution appropriate to the polymer characteristic and applying the statistical distribution to a recently measured instantaneous value of the polymer property so as to have an instantaneous distribution of the polymer property and a means of adding together the instantaneous distributions of the polymer property in order to obtain the cumulative distribution of the polymer property in the reactor.

First claim

We claim:

1. A method comprising:
monitoring an instantaneous average property of polymers being produced by a polymerization reaction occurring in a reaction vessel a plurality of times during the polymerization reaction;
determining a corresponding change in polymer concentration in the reaction vessel based at least in part on successive measurements of the instantaneous average property of the polymers;
computing an instantaneous polymer property distribution corresponding to the most recently measured instantaneous average property using a statistical distribution; and
adding together the instantaneous distributions of the polymer with their amplitudes proportional to the change in polymer concentration between successive values of instantaneous average polymer property, to obtain a cumulative polymer property distribution of up to the latest measured value of the instantaneous average polymer property and change in polymer concentration.

2. The method according to claim 1 , wherein the instantaneous average property is obtained using an ACOMP system.

3. The method according to claim 1 , further comprising the use of the instantaneous polymer property distribution and cumulative polymer property distribution to monitor a polymerization reaction.

4. The method according to claim 1 , further comprising the use of the instantaneous polymer property distribution and cumulative polymer property distribution to control a polymerization reaction.

5. The method according to claim 1 , further comprising the use of the cumulative polymer property distribution to provide analytical characterization of the final polymer product.

6. The method according to claim 1 , wherein the property of the polymers is selected from the group consisting of: molecular weight, intrinsic viscosity, and comonomer composition.

7. The method according to claim 1 , wherein the monitoring an instantaneous average property of polymers being produced by a polymerization reaction occurring in a reaction vessel a plurality of times during the polymerization reaction comprises:
measuring polymer concentration and a cumulative average property of polymers being produced by a polymerization reaction occurring in a reaction vessel a plurality of times during the polymerization reaction; and
deriving the instantaneous average property of polymers based upon the measured cumulative average property and polymer concentration.

8. A method comprising:
monitoring an instantaneous weight average molecular weight (Mw,inst) of polymers being produced by a polymerization reaction occurring in a reaction vessel a plurality of times during the polymerization reaction;
determining a corresponding change in polymer concentration ΔCp in the reaction vessel based at least in part on successive values of the instantaneous weight average molecular weight;
generating an instantaneous molecular weight distribution (IMWD) at the change in the polymer concentration ΔCp by using the instantaneous weight average molecular weight as the mean for the IMWD;
computing a histogram of instantaneous weight average molecular weight distributions (IMWDs), with the amplitude of the IMWDs proportional to the change in polymer concentration between successive values of instantaneous weight average molecular weight; and
computing a cumulative molecular weight distribution (CMWD) based on the histogram using a statistical distribution appropriate to the polymerization reaction.

9. The method according to claim 8 , wherein monitoring the instantaneous weight average molecular weight comprises minimizing the effect of measurement noise in the analog output signal using a derivative algorithm.

10. The method according to claim 9 , wherein the derivative algorithm comprises computing instantaneous weight average molecular weight, M w,inst , according to:

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Assignees

• Yokogawa Fluence Analytics Inc
• The Administrators Of The Tulane Educational Fund

Inventors

• Reed Wayne Frederick
• Montgomery Rick D
• Drenski Michael Felix
• Wu Aide

Classifications

• G01N21/75 Primary

  Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated (systems in which material is burnt in a flame or plasma G01N21/72, G01N21/73) · CPC title

• B01J19/0006 Primary

  Controlling or regulating processes (controlling or regulating in general G05) · CPC title

• C08F20/56

  Acrylamide; Methacrylamide · CPC title

• B01J2219/00186

  controlling the composition of the reactive mixture · CPC title

• B01J2219/002

  inside the reactor · CPC title