Video Transcript
Which of the following is the best description of an addition polymer? A) A polymer made by linking monomers together, without forming by-products. B) A polymer made by linking monomers together and releasing water or other small molecules. C) A polymer made by linking different monomers in a well-defined sequence. D) A polymer that can be easily added to other polymers. Or E) a polymer that can be linked to itself to make a longer polymer.
The first statement suggests that an addition polymer is formed from individual monomers all joined together, without any by-products. In the second statement, it suggested that lots of monomers are joined together, with the loss of a small molecular per monomer. So part of the monomer goes into the polymer and part of it gets left behind.
The third statement suggests that addition polymers are made from different monomers that are put together in a defined sequence. In the fourth scenario, we have one polymer being bolted on to that of another. And the final option is that an addition polymer can be bolted onto itself to extend its length.
Our job is to figure out which one of these best describes an addition polymer. The word addition polymer has two parts. Addition refers to how the polymer is made, while polymer means that the chemical was made up of individual units that were stitched together. The simplest definition of an addition polymer is that it’s made from monomers without by-products.
A good example of an addition polymer is polyethene which is made from ethene without any by-products. Each unit of ethene has been added to the next, without any losses. So the mass of the polymer you get out of an addition polymerisation is equal to the mass of monomer that reacted.
This description of an addition polymer is most like statement A, a polymer made by linking monomers together without forming by-products. Statement B describes a condensation polymer not an addition polymer. When condensation polymers are made, water or other small molecules are released. Statement B describes a type of copolymer where different monomers are mixed together in the same polymer. Meanwhile, statement D, a polymer that can be easily added to other polymers, describes part of a block copolymer. As this is not a necessary feature of an addition polymer, this is not a correct answer.
Finally, a polymer that can be linked to itself to make a longer polymer doesn’t have a distinctive name. But it’s not a necessary condition to be an addition polymer. So it’s not the best description. Of all the descriptions given, the best one of an addition polymer is a polymer made by linking monomers together without forming by-products. For this question, you don’t necessarily need to know the names of the other types of polymers. You just need to identify what the definition of an addition polymer is and find the statement that matches it best.
