Key insights

• 🦴 The oldest glue, over 8,000 years old, was made from animal bone and plant materials.
• 🌐 Glue and tape have been essential for human civilization.
• 🌿 Adhesives can be natural or synthetic, made from proteins and carbohydrates.
• 🔬 Glue and tape work through adhesive and cohesive bonds, with some glues using solvents that may be harmful to inhale.
• ⚗️ Glues with chemical reactions create strong irreversible bonds, while tapes form weaker reversible bonds through Van der Waals forces.
• 📦 Tape composition includes elastic and tacky components on a backing material.
• 💪 Different adhesives have different strengths and properties; super glues form strong bonds, but epoxy glues offer higher resistance to heat and shearing.
• 🔍 Glues and adhesives have specific uses based on factors like surface area, heat resistance, and zero gravity environments.

Q&A

• How do factors like surface area and environment affect the choice of adhesives?

  Different glues and adhesives are suitable for different purposes based on factors like surface area, heat resistance, and zero gravity environments. For example, duct tape has advantages like instantaneous stickiness in emergencies, while epoxy glues are essential for applications requiring strong and enduring bonds. In zero gravity, duct tape is preferred for repairs over liquid glues.

• What are the strengths and properties of different adhesives?

  Different adhesives have different strengths and properties. For instance, super glues form strong bonds, while epoxy glues offer higher resistance to heat and shearing. Van der Waals forces also play a role in adhesive strength, and no single adhesive is best for all circumstances. Cyanoacrylates (super glues) may form the strongest bonds, and two-component epoxy glues have higher resistance to heat and shearing. Epoxy glues are compatible with a wider range of surfaces, while super glue may be the best choice for hanging heavy objects like an anvil.

• What is the composition of tape?

  Tape composition includes a backing, elastic component, and tackifier. The stickiness is determined by the proportions and thickness of the adhesive. No chemical reaction occurs when tape is pressed onto a surface, and the adhesive flows into cracks and grooves of the surface due to viscoelasticity, allowing it to slide into cracks and stay in place.

• What types of bonds do glues and tapes form?

  Glue forms strong irreversible bonds through chemical reactions, while tapes form weaker reversible bonds through Van der Waals forces. Glued surfaces cannot be reattached without new glue after drying, and Van der Waals forces occur between materials when extremely close.

• How do glue and tape work?

  Glue and tape require adhesive and cohesive bonds to work. Adhesive bonds form between the adhesive and the surface being stuck to, while cohesive bonds occur within the glue or tape's own molecules. Most glues use adhesive polymers dissolved in a solvent to prevent sticking inside the bottle, and the strong smell of many glues comes from the solvent, which evaporates when exposed to air. Some glues use water as a solvent, while others use potentially harmful chemicals.

• What is the oldest glue made from?

  The oldest glue, over 8,000 years old, was made from animal bone and plant materials. Glue and tape have been essential for human civilization. Adhesives can be natural or synthetic, made from proteins and carbohydrates.

• 00:07 The oldest glue, over 8,000 years old, was made from animal bone and plant materials. Glue and tape have been essential for human civilization. Adhesives can be natural or synthetic, made from proteins and carbohydrates.
• 00:51 Glue and tape work through adhesive and cohesive bonds, with some glues using solvents that may be harmful to inhale.
• 01:32 Glues with chemical reactions create strong irreversible bonds, while tapes form weaker reversible bonds through Van der Waals forces.
• 02:15 Tape composition includes elastic and tacky components on a backing material. No chemical reaction occurs when tape is applied; the adhesive flows into surface cracks and grooves.
• 03:01 Different adhesives have different strengths and properties; super glues form strong bonds, but epoxy glues offer higher resistance to heat and shearing.
• 03:46 Glues and adhesives have specific uses based on factors like surface area, heat resistance, and zero gravity environments. Duct tape is better for certain applications, while epoxy glues are necessary for others.