Browse Prior Art Database

Polymer Gel Point Indicator

IP.com Disclosure Number: IPCOM000081433D
Original Publication Date: 1974-Jun-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Schuessler, PW: AUTHOR

Abstract

This indicator uses inexpensive and simple apparatus to indicate when a polymer, such as an epoxy, starts to gel during its cure cycle.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Polymer Gel Point Indicator

This indicator uses inexpensive and simple apparatus to indicate when a polymer, such as an epoxy, starts to gel during its cure cycle.

A sample A, Fig. 1, of the uncured polymer is placed in tube B. The tube B is immersed in a constant-temperature bath, not shown, at time t0. Concurrently, air bubbles C are passed through the polymer via the capillary tube D and vacuum pump system E at a controlled rate, e.g., 100 cubic centimeters per minute.

As the polymer A cures, i.e., polymerizes, it thickens and the bubbles C freely form and break loose at the polymer's surface F. At time tf later, the last bubble breaks loose and the fluid motion in the sample C terminates. By observing the bubble action and elapsed time, i.e., tf - t0, while the polymer A is in the constant- temperature bath, an indication of the polymer's gel point for the particular temperature is obtained.

Fig. 2 is a time-temperature plot of the typical gel point characteristic of a polymer for different bath temperatures, it being noted that the polymer gels faster at the higher temperatures.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]