11.12.2012 Views

Nondestructive testing of defects in adhesive joints

Nondestructive testing of defects in adhesive joints

Nondestructive testing of defects in adhesive joints

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

content due to higher filler-polymer <strong>in</strong>teractions compared to untreated and silane-treated silica.<br />

PTh- and untreated-silica filled EPDM show similar levels <strong>of</strong> bound rubber content, lower than<br />

the silane-treated silica.<br />

PTh-silica filled EPDM (EPTh), SBR (SPTh), and NBR (NPTh) show self-cur<strong>in</strong>g<br />

behavior as shown <strong>in</strong> Fig. 2. This self-cur<strong>in</strong>g behaviour is due to the presence <strong>of</strong> sulphur moieties<br />

<strong>in</strong> the deposited PTh-film on the silica surface.<br />

Torque (dNm)<br />

16<br />

12<br />

8<br />

4<br />

SPTh (S: S-SBR; PTh: Plasma-thiophene coated silica)<br />

EPTh (E: EPDM; PTh: Plasma-thiophene coated silica)<br />

NPTh (S: NBR; PTh: Plasma-thiophene coated silica)<br />

0<br />

0 4 8 12 16 20 24 28 32<br />

Time (m<strong>in</strong>s.)<br />

Fig. 2: Self-cur<strong>in</strong>g behaviour <strong>of</strong> PTh-silica filled SBR, EPDM and NBR<br />

For all three polymers, tensile strength is <strong>in</strong>creased significantly due to the PTh-<br />

treatment. However, for SBR (SPTh) the addition <strong>of</strong> PTh-coated silica results <strong>in</strong> higher tensile<br />

strength as well as a higher modulus at 300% elongation and lower elongation at break values as<br />

shown <strong>in</strong> Fig. 3. This can be expla<strong>in</strong>ed by a better dispersion and filler-polymer <strong>in</strong>teraction as<br />

well as a higher crossl<strong>in</strong>k density.<br />

4

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!