block copolymer
Quick Summary
A block copolymer is a polymer made of blocks of simpler polymers. These polymers consist of two or more different types of repeating units that occur in long sequences, or blocks. For example, styrene-butadiene-styrene (SBS) and styrene-isoprene-styrene (SIS) are triblock copolymers with polystyrene blocks at each end and a butadiene or isoprene block in the center.12
This structure allows block copolymers to exhibit properties of both types of polymers, making them thermoplastic elastomers. They possess the elasticity of rubber and can be molded like plastic. This dual nature makes them useful in applications requiring both flexibility and durability, such as in adhesives and molded parts. Block copolymers can also be used to improve adhesion in blends of immiscible polymers.123
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rubberThe rise of synthetic rubberFor example, block copolymers, in which a long sequence of one chemical unit is followed in the same molecule by a long sequence of another, were made, using many different units and sequence lengths. New oil-resistant and heat-resistant elastomers were introduced, including the styrene-acrylonitrile copolymers, the polysulfides,…
Read MoreFor example, block copolymers, in which a long sequence of one chemical unit is followed in the same molecule by a long sequence of another, were made, using many different units and sequence lengths. New oil-resistant and heat-resistant elastomers were introduced, including the styrene-acrylonitrile copolymers, the polysulfides,…
Read More- elastomerBlock copolymers
Another type of intermolecular association is shown by thermoplastic block copolymers, where each molecule consists of long sequences, or blocks, of one unit followed by long sequences of another. Because different polymers are generally incompatible (i.e., do not dissolve into one another), blocks…
Read MoreAnother type of intermolecular association is shown by thermoplastic block copolymers, where each molecule consists of long sequences, or blocks, of one unit followed by long sequences of another. Because different polymers are generally incompatible (i.e., do not dissolve into one another), blocks…
Read More - copolyester elastomer
Copolyester elastomers are block copolymers—that is, the two different types of chemical repeating units that make up the chainlike molecules occur in long sequences, or blocks. The hard sequences usually consist of polybutylene terephthalate (PBT), a stiff polyester resin. The soft sequences consist of any one of a…
Read MoreCopolyester elastomers are block copolymers—that is, the two different types of chemical repeating units that make up the chainlike molecules occur in long sequences, or blocks. The hard sequences usually consist of polybutylene terephthalate (PBT), a stiff polyester resin. The soft sequences consist of any one of a…
Read More