Polymer characterization apparatus

• US 4,258,564 A
• Filed: 12/06/1979
• Issued: 03/31/1981
• Est. Priority Date: 03/28/1979
• Status: Expired due to Term

• Current Assignee: Polysar Limited (Bayer AG)
• Original Assignee: Polysar Limited (Bayer AG)
• Inventors: Hulme, Joseph M., Thibodeau, William E.
• Primary Examiner(s): Petrakes, John
• Assistant Examiner(s): ROSKOS, JOSEPH
• Application Number:
  US06/101,016
• Time in Patent Office: 481 Days
• Field of Search: 73/61.1 C, 73/55, 73/53, 73/61 R, 210/31 C, 210/198 C, 422/70
• US Class Current: 73/61.52
• CPC Class Codes: B01D 15/34 Size selective separation, e.g. size exclusion chromatography, gel filtration, permeation
• CPC Class Codes: G01N 30/02 Column chromatography
• CPC Class Codes: G01N 33/442 Resins; Plastics

Abstract

An apparatus and a method of operating the apparatus are provided for obtaining a sample of polymer cement and for determining the polymer content of the cement and a molecular weight of the polymer. The apparatus comprises a valve means in combination with a dilution means whereby dilute polymer solution is supplied to a solution viscometer means and to a gel permeation chromatographic means. Operation of the apparatus is controlled by a micro computer. The apparatus and method are useful for determining the polymer content and polymer molecular weight of, for example, polybutadiene formed in a polymerization reactor.

Claims

1. An apparatus for obtaining from a polymerization reactor a sample of polymer dissolved in one or more hydrocarbon diluents and for determining the polymer content of said sample and a molecular weight of said polymer, which apparatus comprises:

(a) polymerization reactor means,

(b) line for removing from said reactor means a polymeric product dissolved in one or more hydrocarbon polymerization diluents,

(c) valve means for the removal from said line of an essentially constant volume sample of said polymeric product dissolved in said diluent,

(d) means for storing hydrocarbyl solvent,

(e) dilution means for adding hydrocarbyl solvent to and mixing said hydrocarbyl solvent with said essentially constant volume sample to provide an essentially constant volume of dilute polymer solution,

(f) line for transferring said dilute polymer solution to a selector valve,

(g) a first line from said selector valve for transferring a constant volume of said dilute polymer solution to a solution viscometer means which is maintained at an essentially constant temperature,

(h) line for transferring hydrocarbyl solvent to said solution viscometer means,

(i) a second line from said selector valve for transferring a constant volume of said dilute polymer solution to one or more gel permeation chromatographic columns,

(j) line for transferring hydrocarbyl solvent to said gel permeation chromatographic columns,

(k) means for causing said dilute polymer solution to flow through a capillary in said solution viscometer means and to activate a timing device to determine and record the flow time for the flow through said capillary of a constant volume of said dilute polymer solution,

(l) means for causing said hydrocarbyl solvent to flow through a capillary in said solution viscometer means and to activate a timing device to determine and record the flow time for the flow through said capillary of a constant volume of said hydrocarbyl solvent,

(m) means for causing the flow through said one or more gel permeation chromatographic columns of hydrocarbyl solvent at an essentially constant rate of flow,

(n) means for determining and recording the refractive index difference as a function of time for the effluent from said one or more gel permeation chromatographic columns, said refractive index difference being the difference between the refractive index of the column effluent and that of a control fluid,

(o) micro computer means programmed to control the operation of the apparatus, to determine and record said flow times from said solution viscometer means, to record said refractive index difference as a function of time and to calculate from said refractive index difference the polymer content of said sample and from said flow times and polymer content a molecular weight of said polymer, and

(p) recorder/display means for providing the data calculated in (o).

3. The apparatus of claim 1 or 2 wherein said valve means comprises a two-position valve having a housing equipped with ports, the chamber of said housing containing a movable two-position valve core equipped with flow channels each of which separately communicates with two adjacent ports, a first port being in communication with inlet means for polymer cement, a second port being in communication with outlet means for said cement, a third port being in communication with a dilution means, a fourth port being in communication with the dilute polymer solution in said dilution means and a fifth port being for removal of dilute polymer solution from the valve means, a first flow channel communicating in its first position with said first and second ports and in its second position with said second and third ports and a second flow channel communicating in its first position with said third and fourth ports and in its second position with said fourth and fifth ports.

4. The apparatus of claim 1 or 2 wherein said dilution means comprises a narrow diameter cylindrical chamber connected at its upper end to the third port of said valve means and connected at its lower end to a wide diameter closed cylindrical chamber which has at the side wall at its lower end a line in communication with the fourth port of said valve means and the solvent storage means and has at its upper end a line having a valve therein whereby said line may be connected to a supply of compressed gas or to the atmosphere, said narrow diameter cylindrical chamber having located concentrically therein and axially slidably movable within a close fitting plunger equipped with seals to prevent fluid leakage and having at its lower end depending into said wide diameter chamber a flange end for abutting engagement with the under surface of the wide diameter chamber at the point where the narrow diameter cylindrical chamber is attached to the wide diameter chamber, and said wide diameter closed cylindrical chamber having concentrically located therein and axially slidably movable within a close fitting double acting barrier piston equipped with seals to prevent fluid leakage and having a stirring means located within said wide diameter chamber and below said double acting barrier piston.

2. An apparatus for obtaining from a polymerization reactor a sample of polymer dissolved in one or more hydrocarbon diluents and for determining the polymer content of said sample and a molecular weight of said polymer, which apparatus comprises:

(a) polymerization reactor means,

(b) line for removing from said reactor means a polymeric product dissolved in one or more hydrocarbon polymerization diluents,

(c) valve means for the removal from said line of an essentially constant volume sample of said polymeric product dissolved in said diluent,

(d) a first means for storing a first hydrocarbyl solvent,

(e) a second means for storing a second hydrocarbyl solvent,

(f) dilution means for adding and mixing said first hydrocarbyl solvent with said essentially constant volume sample to provide an essentially constant volume of dilute polymer solution,

(g) line for transferring said dilute polymer solution to a selector valve,

(h) a first line from said selector valve for transferring a constant volume of said dilute polymer solution to a solution viscometer means which is maintained at an essentially constant temperature,

(i) a line for transferring said first hydrocarbyl solvent to said solution viscometer means,

(j) a second line from said selector valve for transferring a constant volume of said dilute polymer solution to one or more gel permeation chromatographic columns,

(k) a line for transferring said second hydrocarbyl solvent to said gel permeation chromatographic columns,

(l) means for causing said dilute polymer solution to flow through a capillary in said solution viscometer means and to activate a timing device to determine and record the flow time for the flow through said capillary of a constant volume of said dilute polymer solution,

(m) means for causing said first hydrocarbyl solvent to flow through said capillary in said solution viscometer means and to activate a timing device to determine and record the flow time for the flow through said capillary of a constant volume of said solvent,

(n) means for causing the flow through said one or more gel permeation chromatographic columns of said second hydrocarbyl solvent at an essentially constant rate of flow,

(o) means for determining and recording the refractive index difference as a function of time for the effluent from said one or more gel permeation chromatographic columns, said refractive index difference being the difference between the refractive index of the column effluent and that of a control fluid,

(p) micro computer means programmed to control the operation of the apparatus, to determine and record said flow times from said solution viscometer means, to record said refractive index difference as a function of time and to calculate from said refractive index difference the polymer content of said sample and from said flow times and polymer content a molecular weight of said polymer, and

(q) recorder/display means for providing data calculated in (p).

5. A method for determining for a sample of polymer dissolved in one or more hydrocarbon diluents and obtained from a polymerization reactor the polymer content and a molecular weight of said polymer, which method comprises:

(a) transferring an essentially constant volume of said sample to a dilution means and adding to and mixing with said sample a hydrocarbyl solvent to provide an essentially constant volume of dilute polymer solution,

(b) transferring said dilute polymer solution to a selector valve,

(c) transferring from said selector valve a constant volume of said dilute polymer solution to a solution viscometer means maintained at an essentially constant temperature,

(d) transferring from said selector valve a constant volume of said dilute polymer solution to one or more gel permeation chromatographic columns,

(e) causing said dilute polymer solution to flow through a capillary in said solution viscometer means and causing the activation of a timing device to determine and record the flow time for a constant volume of said dilute polymer solution to flow through said capillary,

(f) transferring hydrocarbyl solvent to said solution viscometer means, causing said hydrocarbyl solvent to flow through said capillary and causing the activation of a timing device to determine and record the flow time for a constant volume of said hydrocarbyl solvent to flow through said capillary,

(g) causing the flow through said one or more gel permeation chromatographic columns of hydrocarbyl solvent at an essentially constant rate of flow and causing the determining and recording of the refractive index difference as a function of time for the effluent from said one or more columns, said refractive index difference being the difference between the refractive index of the column effluent and that of a control fluid,

(h) causing a micro computer means to direct the transfers and flows to take place, to determine and record the flow times through the capillary of the solution viscometer means, to record the refractive index difference as a function of time, to calculate from said refractive index difference the polymer content of said sample, to calculate from said polymer content and from said flow times a molecular weight of the polymer and to cause a recorder/display means to provide the data calculated.

7. The method of claim 5 wherein said polymer is polybutadiene and said hydrocarbyl solvent is selected from benzene, toluene, cyclohexane and tetrahydrofuran.

6. A method for determining for a sample of polymer dissolved in one or more hydrocarbon diluents and obtained from a polymerization reactor the polymer content and a molecular weight of said polymer, which method comprises:

(a) transferring an essentially constant volume of said sample to a dilution means and adding to and mixing with said sample a first hydrocarbyl solvent to provide an essentially constant volume of dilute polymer solution,

(b) transferring said dilute polymer solution to a selector valve,

(c) transferring from said selector valve a constant volume of said dilute polymer solution to a solution viscometer means maintained at an essentially constant temperature,

(d) transferring from said selector valve a constant volume of said dilute polymer solution to one or more gel permeation chromatographic columns,

(e) causing said dilute polymer solution to flow through a capillary in said solution viscometer means and causing the activation of a timing device to determine and record the flow time for a constant volume of said dilute polymer solution through said capillary,

(f) transferring said first hydrocarbyl solvent to said solution viscometer means, causing said solvent to flow through said capillary and causing the activation of a timing device to determine and record the flow time for a constant volume of said solvent to flow through said capillary,

(g) causing the flow through said one or more gel permeation chromatographic columns of a second hydrocarbyl solvent at an essentially constant rate of flow and causing the determining and recording of the refractive index difference as a function of time for the effluent from said one or more columns, said refractive index difference being the difference between the refractive index of the column effluent and that of a control fluid,

(h) causing a micro computer means to direct the transfers and flows to take place, to determine and record the flow times through the capillary of the solution viscometer means, to record the refractive index difference as a function of time, to calculate from said refractive index difference the polymer content of said sample, to calculate from said polymer content and from said flow times a molecular weight of the polymer and to cause a recorder/display means to provide the data calculated.

8. The method of claim 6 wherein said polymer is polybutadiene, said first hydrocarbyl solvent is toluene and said second hydrocarbyl solvent is cyclohexane.