Concept:Cyanoacrylate adhesives (commonly known as super glue) undergo rapid anionic polymerization in the presence of trace moisture, forming high-strength bonds between non-porous surfaces.
Formula / Reaction:$$n\,\text{CH}_2=\text{C}(\text{CN})\text{COOCH}_3 + \text{H}_2\text{O (trace)} \longrightarrow -[\text{CH}_2-\text{C}(\text{CN})(\text{COOCH}_3)]_n-$$
Solution:- Super glue is specifically formulated for fast, rigid bonding of non-porous materials such as metals, glass, ceramics, and jewelry.
- It cures within seconds at room temperature without requiring mixing or external heat.
Why other options are incorrect:- Epoxy resin: Requires manual mixing of resin and hardener and exhibits a longer curing time, making it less convenient for delicate jewelry repairs.
- Silicon resin: Forms flexible, elastomeric joints that lack the rigid shear strength required for fine metal and gemstone settings.
- Starch: A weak, water-soluble natural adhesive used primarily for paper products.
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