Question

One type of silicon adhesive uses a polymer that has two $OH$ groups left on the ends of the chain:
$HO-Si\left(C{H}_3{)}_2\right[O-Si(C{H}_3{)}_2{]}_n-O-Si(C{H}_3{)}_2-OH$
It has been found that this kind of polymer reacts easily with an organic-silicon molecule that contains acetate $\left(C{H}_{3}COO\right)$ group. Which of these three molecules $C{H}_{3}COOSi(C{H}_3{)}_3$, $\left(C{H}_{3}COO{)}_{2}Si\right(C{H}_3{)}_2$, $(C{H}_{3}COO{)}_{3}SiC{H}_3$ would you choose to add to the hydroxy polymer in order to make a strong adhesive?

• A. $C{H}_{3}COOSi(C{H}_3{)}_3$,
• B. $\left(C{H}_{3}COO{)}_{2}Si\right(C{H}_3{)}_2$
• C. $(C{H}_{3}COO{)}_{3}SiC{H}_3$
• D. None of the above

Answer 1

Answer: (C)

$(C{H}_{3}COO{)}_{3}SiC{H}_3$

${\left(C{H}_{3}COO\right)}_{3}SiC{H}_3-$triacetoxy (methyl) silane.
This should give the cross-linking necessary for strength of adhesives.