SU1241096A1 - Method of determining bulk modulus of polymer during its solidification - Google Patents

Abstract

The invention relates to a technique for determining the properties of polymeric materials; The aim of the invention is to improve the accuracy of determining the bulk modulus of polymeric materials during their curing. The bellows 1 is fastened with the bottom end on the base 2. At the upper end, the cover 3 is fixed with a hole in the center, hermetically closed with a stopper 4. The bellows 1 without sample 5 is removed, the relationship between the load increment and the change in its height is determined. Then the bellows 1 is filled the molten polymer 6 is closed and loaded again. The bulk polymer module K is calculated using the formula K 4Pg -aPj / IJ RP, where a Pj is the increment of force during compression of the bellows with the sample; lRs - compressing force of the bellows without. sample; S is the relative decrease in the height of the sample with the bellows; R is the average radius of the bellows. 1 il. (L to 4 R od

Description

The invention relates to a test technique and can be used to determine the mechanical properties of polymeric materials.

The aim of the invention is to increase the accuracy of determining the bulk modulus and reduce the cost of the method.

The drawing shows a device for carrying out the method.

The device contains sylphs 1 fixed on base 2, the upper end of which is closed by a cap 3 fixed, for example, by means of a cold-curing adhesive. In the center of the rim 3, a hole is made, hermetically closed by the stopper 4. Elastic elements 5 with strain gauges (not shown) are mounted between the base 2 and the cap 3 to register the movement of the cover 3 relative to the base 2,

The method for determining the bulk modulus of a polymer is implemented as follows.

The bellows 1, fixed on the base 2, with its krppka 3 installed on the upper end and elastic elements 5 is placed on a testing machine (not shown), loading and register the increment of the force Pc depending on the change in the relative height

 (Bn - h) / h ,,. where h is the original cell of the bellows;

h is the current height of the bellows. Then the test polymer 6 is added to the SILPHONE 1, which is hermetically sealed with the stopper 4, after having removed, if necessary, the air dusting by vacuuming. Then the device with the test polymer 6 is loaded at the ends on the testing machine, registering the increment l Pg effort with a corresponding change relative to the height S ,,

Editor A. Gulko

Compiled by Y. Makhov Tehred M. Morgvital

Order 3480/37 Circulation 778 Subscription

VNUTSH of the USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

j

1241096.2

The bulk modulus K of the polymer is determined by the formula

dR

K - fPg JW

O

5 jo

five

g

five

where R is the average radius of the bellows. Example. To determine the bulk modulus, a 32 mm diameter and 52 mm height symphony was used. The signal from the strain gauges applied to the elastic elements was applied to a self-recording potentiometer. The experiments were carried out at polymer temperature. During the polymerization for 6 hours, the bulk modulus of the polymer samples increased from 15 to 170 MPa.

Claims (1)

Invention Formula The method for determining the bulk modulus of the polymer during its curing, which consists in placing the polymer specimen in a vessel close to its walls, compressing the specimen in height, and registering the height variation depending on the compressive force of the specimen, according to which the bulk modulus is distinguished - so that, in order to improve the accuracy of determining the bulk modulus and reduce the cost of the method, BELLOWTHE is used as a vessel, which is precompressed without a sample and the relationship between the increment of force is determined and changed the height of the bellows, and the bulk modulus K of the polymer is calculated by the formula TO  - Drs 0 five where lpe drs s r increment of force during compression of the bellows with the sample; increment of the compressive force of the bellows without a sample; average radius of the bellows. Proofreader M. Maksimishinets