chap 9 key terms Flashcards
addition polymer
Addition polymer- a polymer that is formed by an addition reaction, where many monomers bond together by rearrangement of C=C double bonds without the loss of any atom or molecule. An addition polymer is made from unsaturated monomers.
addition polymerisation
Addition polymerisation- The process by which a polymer is formed by an addition reaction, which many unsaturated monomers bond together by rearrangement of C=C double bonds without the loss of any atom or molecule.
amorphous
a structure that has no consistent arrangement of particles.
biobased
Biobased- Describes a material intentionally made from substances derived from living (or once-living) organisms.
biodegradable
Biodegradable- Capable of being decomposed by bacteria or other living organisms.
bio-monomer
Bio-monomer- Monomers chemically synthesised from biomass, such as starch, sugar or general food waste.
bio-polyethene (bio-PE)
Bio-polyethene (bio-PE)- Polyethene formed from ethanol that has been formed by fermentation.
Bio-polyethylene terephthalate (bio-PET)
Bio-polyethylene terephthalate (bio-PET)- PET formed using ethane-1,2-diol that has been formed from bioethanol.
bio-plastic
Bio-plastic- Polymers formed from renewable biomass such as starch or sugar.
bio-polypropene (bio-PP)
Bio-polypropene (bio-PP)- Polypropene formed from propene that has been formed from either ethanol or butan-1-ol from renewable biomass.
Branches
Branches- The regular or irregular attachment of side chains to a polymer’s backbone chain.
catalyst
Catalyst- A substance that increases the rate of a reaction but is not consumed in the reaction. The catalyst provides a new reaction pathway with a lower activation energy.
chemical recycling
Chemical recycling- Any process by which a polymer is chemically reduced to its original monomer.
compostable
Compostable- Capable of disintegrating into natural elements within 90 days in a compost environment, leaving no toxicity in the soil.
condensation polymer
Condensation polymer- A polymer formed by a condensation reaction, involving the elimination of a small molecule (often water) when monomers bond together. The monomers have functional groups at both ends of the molecule.
copolymer
Copolymer- A polymer that is made from two or more monomers.
cracking
Cracking- A chemical process during which carbon-carbon bonds in alkanes are broken to form smaller molecules and some unsaturated molecules.
cross-link
Cross-link- a covalent bond between different chains of atoms in a polymer or other complex molecule.
crystalline region
Crystalline region- A region where polymer molecules line up parallel to each other and pack closely together.
elastomer
Elastomer- A rubbery material composed of long molecules that is capable of recovering its original shape after being stretched.
ester
Ester- A compound produced by the reaction between a carboxylic acid and an alcohol with the elimination of a molecule of water.
high-density polyethene (HDPE)
High-density polyethene (HDPE)- A form of the polymer polyethene formed from polymer chains with very few, short branches. This means the polymer chains are packed together closely, making the polymer dense. HDPE can have a percentage crystallinity as high as 95% and has excellent mechanical properties. HDPE is used to make pipes, buckets and food containers, such as milk bottles.
hydrolysis
Hydrolysis- Any chemical reaction in which a molecule of water breaks one or more chemical bonds.
linear low-desnity polyethene (LLDPE)
Low density polyethene (LDPE)- A form of the polymer polyethene which has a high degree of short and long chain branching. This means the polymer chains do not pack together closely in the crystal structure. It has therefore weaker intermolecular forces, resulting in a lower tensile strength and increased ductility.
mechanical recycling
Mechanical recycling- refers to operations that aim to recover plastic waste using mechanical process such as grinding and separating.
microbial
relating to microbes or microorganisms, often bacteria
microplastic
Microplastic- Extremely small pieces of plastic debris in the environment resulting from the disposal and breakdown of consumer products and industrial waste.
monomer
Monomer- A small molecule that can react to form long chains of repeating units, called polymers.
natural polymer
Natural polymer- Long chains of repeated units which are obtained from nature, meaning they can be observed in and extracted from living things.
organic recycling
Organic recycling- The use of enzymes or microorganisms to compost a polymer back to its monomer or to non-toxic smaller molecules.
plastic
Plastic- A property of a material that can be reshaped by application of heat and pressure. In society, polymers are often referred to as plastics.
polymer
Polymer- A long-chain molecule that is formed by the reaction of large numbers of repeating units (monomers).
plasticiser
Plasticiser- Small molecules that soften a plastic by weakening intermolecular attractions between polymer chains.
polymerisation
the process of synthesizing a polymer
side group
a group of atoms attached to a backbone chain of a long molecule
thermoplastic
Thermoplastic- A thermoplastic polymer will often and melt when heated, allowing it to be remoulded or recycled. When heated sufficiently, the intermolecular bonds break, allowing the molecules to become free to move and be remoulded.
thermosetting
Thermosetting- When a thermosetting polymer is heated, it does not melt, but at high temperatures, covalent bonds are broken and it decomposes or burns. It cannot be moulded into a different shape.
unsaturated
Unsaturated- A hydrocarbon composed of molecules with one or more carbon-carbon double or triple bonds.
