Molecular Structure of Materials Flashcards
What do the properties of solid materials depend on?
How their particles are arranged and held together
What is natural rubber?
A mass of long-chain molecules.
What are atoms within the chains held together by?
Covalent bonds, but there are very weak forces between the molecules.
What does this mean the long polymer molecules can do?
Slide over one another and the material can stretch.
What is natural rubber?
Very flexible
Has a low melting point because little energy is needed to separate the molecules.
What is vulcanised rubber?
A mass of tangled molecules
What are the atoms within the chains held together by?
Covalent bonds
What do the molecules also have?
Cross-links
What are cross-links?
Strong covalent bonds between the long-chain molecules
What is vulcanised rubber?
Quite rigid and hard to stretch as the molecules won’t slide over each other
Needs lot of energy to separate the molecules and has a high melting temperature.
