Название: Sticking Together
Автор: Steven Abbott
Издательство: Ingram
Жанр: Химия
isbn: 9781839160158
isbn:
11.7 Holding Ourselves Together
11.9 It's All about Specific Molecules
11.11 The Unity of (Adhesion) Science
Glossary
Accelerator | An additive to make the adhesive set faster |
Adherend | The thing being stuck via the adhesive |
Adhesion promoter | A low-level additive that increases the adhesion |
Alcohol | A molecule containing an –OH group |
Amine | A group based on nitrogen and two hydrogens, shown as –NH2 |
APTES | A common adhesion promoter that is both an amine and a silane |
Backing tape | The carrier film for a PSA. Sometimes just called “backing” |
Butt test | Pulling apart in a straight line |
Catalyst | Something which makes a reaction go faster without itself being consumed by the reaction |
Coalescence | Small, semi-solid particles flowing together to give a continuous solid |
Crack energy | The energy trying to open a crack across the interface |
Creep | Slow movement in a joint under a constant load |
Curing | Setting solid via polymerization |
Dahlquist | PSAs must be soft enough to meet the Dahlquist criterion for quick tack |
Dispersant | A molecule added to a formulation to keep particles separated and free flowing |
Dissipation | Converting work into useless heat – this soaks up crack energy and increases adhesion |
DLVO | A theory of why small particles will or will not stick to each other, named after Derjaguin & Landau and Verwey & Overbeek |
G′ & G″ | Measures of the elastic (G′) and fluid (G″) resistance to shear forces |
Griffith's Law | The tendency of a crack to form increases with the size of defects in the system |
Hydrophilic | Likes to be with water, dislikes oil |
Hydrophobic | Dislikes water, likes to be with oil |
Hydroxyl | A group made from one oxygen and one hydrogen, shown as –OH |
Interface | The line between two adhesive components, e.g. between adherend and adhesive |
Ion | A charged molecule or atom. Anions (negative ions) can polymerize cyanoacrylates |
Molecular weight | For polymers this indicates how many monomer units were assembled and, therefore, the length of the chain |
Monomer | A molecule that can react with other monomers to form a polymer |
Peel test | Pulling up from the joint |
Polymers: | |
EVA | (Poly)Ethylene vinyl acetate |
EVOH | (Poly)Ethylene vinyl alcohol |
PE | Polyethylene, commonly called polythene. |
HDPE/LDPE | High Density PE and Low Density PE |
PP | Polypropylene |
PMMA | Polymethylmethacrylate, commonly called Perspex or Plexiglas |
PC | Polycarbonate |
PET | Polyethyleneterephthalate, commonly called polyester |
PDMS | Polydimethylsiloxane, commonly called silicone |
PTFE | Polytetrafluoroethylene, commonly called Teflon |
PVOH | Polyvinylalcohol |
PVA | Polyvinylacetate. Confusingly PVA can also mean Polyvinylalcohol |
PVB | Polyvinylbutyral |
PVP | Polyvinylpyrrolidone |
PSA | Pressure Sensitive Adhesive – common adhesive tape |
Radical | A reactive molecule that produces a new radical after reacting with a monomer |
Retarder | An additive to slow down the setting speed of the adhesive |
Shear test | Pulling apart across the joint |
Stefan's law | Squeezing a blob of adhesive gets much harder as its thickness decreases |
Stress | Force acting across an area |
Strain | Amount of stretch caused by a stress |
Surfactant | “Surface active agent” used in cleaning (“detergent”) and creating emulsions (“emulsifier”). Has a hydrophilic head and hydrophobic tail |
Tack | That easy to know but hard to define feeling of instant adhesiveness |