What is polyaddition reaction?
Polyaddition is a polymerization reaction that forms polymers via individual independent addition reactions. Polyaddition occurs as a reaction between functional groups on molecules with low degrees of polymerization, such as dimers, trimers and oligomers, to form species of higher molar mass.
Is polyurethane a polymer?
Polyurethanes are a class of extremely versatile polymers that are made into flexible and rigid foams, fibres, elastomers, and surface coatings. They are formed by reacting an isocyanate (a compound having the functional group NCO) with an alcohol (having the functional group OH).
What is polycondensation reaction?
In polycondensation, the reaction proceeds between monomers containing two or more reactive functional groups (e.g., hydroxyl, carboxyl and amino) condensing with each other.
Which one is the example of polyaddition polymerization?
Some of the most widely used polymer products of step polyaddition polymerizations include polyurethanes and Diels-Alder polymers.
Is perspex an addition polymer?
Perspex: This is another product of addition polymerization. If the disubstituted ethane, methyl 2-methyl-propenoate, is heated, it polymerizes to give poly(methyl 2-methypropenoate) or PMMA for short. This material is commonly known as Perspex. An organic catalyst, lauryl peroxide, is used in this process.
What type of polymer is polyurethane foam?
Polyurethanes are linear polymers that have a molecular backbone containing carbamate groups (-NHCO2). These groups, called urethane, are produced through a chemical reaction between a diisocyanate and a polyol. First developed in late 1930s, polyurethanes are some of the most versatile polymers.
Is polyurethane a synthetic polymer?
The seven most common types of synthetic organic polymers are: low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), nylon, Teflon, and thermoplastic polyurethane (TPU).
What is the difference between polymerization and polycondensation?
Main differences If in the polymerization process, the composition of the monomer and polymer is identical, in the polycondensation process the composition of the final macromolecule may significantly differ from the original composition of the monomer.