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block copolymer: A copolymer that is a block polymer. In the constituent macromolecules of a block copolymer , adjacent blocks are constitutionally different, i.e. adjacent blocks comprise constitutional unit derived from different species of monomer or from the same species of monomer but with a different composition or sequence distribution ...
It can be used for example to synthesize block copolymers. By definition, a telechelic polymer is a di-end-functional polymer where both ends possess the same functionality. [ 2 ] Where the chain-ends of the polymer are not of the same functionality they are termed di-end-functional polymers.
In addition, block copolymers can exist as many types, including triblock (A-B-A), alternating block (A-B-A-B-A-B), etc. Of these three types, block and gradient copolymers are commonly synthesized through living polymerizations, due to the ease of control living polymerization provides.
An example is the equimolar copolymer of styrene and maleic anhydride formed by free-radical chain-growth polymerization. [39] A step-growth copolymer such as Nylon 66 can also be considered a strictly alternating copolymer of diamine and diacid residues, but is often described as a homopolymer with the dimeric residue of one amine and one acid ...
There are a number of advantages reactive compatibilization has over using the traditional block or graft copolymer as the compatibilizing agent. Unlike the latter approach, reactive compatibilization does not rely on diffusing pre-formed copolymers. Copolymers form at the interfaces of the two immiscible blends and do not need to be dispersed.
As with other living radical polymerization techniques, RAFT allows chain extension of a polymer of one monomer with a second type of polymer to yield a block copolymer. In such a polymerisation, there is the additional challenge that the RAFT agent for the first monomer must also be suitable for the second monomer, making block ...
Polyether block amide or PEBA is a thermoplastic elastomer (TPE). It is known under the tradename of PEBAX® ( Arkema ) and VESTAMID® E ( Evonik Industries ). It is a block copolymer obtained by polycondensation of a carboxylic acid polyamide ( PA6 , PA11 , PA12 ) with an alcohol termination polyether ( Polytetramethylene glycol PTMG), PEG ).
Block copolymers can be made this way. RDRP allows for control of molecular weight and dispersity. However, this is very difficult to achieve and instead a pseudo-living polymerization occurs with only partial control of molecular weight and dispersity. [15] ATRP and RAFT are the main types of complete radical polymerization.