Polymers Flashcards
Polymers
what is polymerisation?
a polymerisation reaction involves joining together a large number of small molecules (monomers), to form a very large molecule (polymer) ONLY
what are the two different types of poltmers?
- addition polymers and condensation polymers
What is Addition polymerisation?
Many monomers join together to form a long molecule (polymers) ONLY
How do alkenes undergo addition polymerisation?
Many alkene monomers join together to form a long-chain polymer ONLY
Are there any waste products during addition polymerisation?
there are no waste products - only the polymer is formed
what does the addition polymerisation of alkenes occur in? Wjhat is formed during this reaction?
in the presence of a catalyst and the alkene monomers link together to form saturated addition polymers
what are addition polymers also known as?
chain growth polymers
why are addition polymers also known as chain growth polymers?
because they are made by the addition of monomers to the reactive end of the growing chain
Addition polymers are formed via which mechanism?
via free radical mechanism
what are the reaction conditions for addition polymerisation?
-High pressure and free radical initiator
How can addition polymerisation also proceed through?
Cation and anion species. this type of mechanism depends on the structure and the type of catalyst used
how is poly(ethene) formed?
ethene molecules link together to form poly ethene (in the presence of a catalyst)
Addition polymers formed from alkenes are?
saturated compounds
why are addition polymers chemically unreactive/inert?
the carbon-carbon bonds are non-polar and can not be hydrolysed
why is this a useful property for the resultant polymer?
since it can not be attacked by acids, alkalis and oxidising agents
draw an equation to show the polymerisation of a SECTION of poly(ethene)?
what are polymers usually represented by?
a repeating unit
what is the repeating unit of poly(ethene)
the repeating unit of poly(ethene) has no brackets
so what is the polymerisation of poly(ethene shown as)
what does n stand for?
n - represents a large whole number
n - is the number of individual molecules (monomers) that join together to form a polymer
Different addition polymers can be made from..?
monomers in which some or all of the hydrogen atoms in ethene have been replaced
draw the structure to show how monomers can be represented by?
What can R be?
RHC=CH2
where R = H, CH2, C6H5, CL, CN, OCOCH3
Why can different polymers be used to make a range of commercial products?
because each polymer has it’s own physical properties, so different polymers can be used to make a range of commercial products