Adhesion evaluation of glass fiber-PDMS interface by means of microdroplet technique

H. Ahmadi

Abstract

This research was intended to measure the interfacial shear strength between fiber/ matrix

systems and to investigate the relation between structure-mechanical properties and performance

of fiber/matrix systems. This work conducted a systematic study on model fiber/matrix systems

to enhance the fundamental understanding on how variation of polymeric compositions (and

hence, different structures), different curing conditions, and fiber surface treatments influence the

interactions between the fiber and matrix.

In order to measure the interfacial shear strength of fiber/matrix systems, the microdroplet

technique was used. In this technique a polymer droplet was deposited on a fiber in the

liquid state. Once the droplet was cured a shear force was applied to the droplet in order to

detach the droplet from the fiber. The amount of the force needed to de-bond the droplet was

directly related to the strength of the bonds formed between the fiber and matrix during the

curing process.

In addition, the micro-droplet technique was used to evaluate effects of different

crosslinker ratio of fiber/ matrix system and also to see if different curing conditions affect the

interfacial shear strength of fiber/ matrix system. Surface treatment was also conducted to

evaluate its effects on the interfacial shear strength of the fiber/ matrix system using microdroplet

technique.

The interfacial shear strength of fiber/ matrix system increased along with the increase of

crosslinker ratio to a limiting value, and it decreased as long as the crosslinker ratio increased.

Curing condition also caused the interfacial shear strength of fiber/ matrix system to increase

when it was cured at higher temperature. Fiber surface treatment exhibited a significant effect to

the interfacial shear strength as well as the fiber/ matrix contact angle measurement.

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