How do you synthesize block copolymers?
There are three principal methodologies for synthesis of block copolymers with well-defined structures: 1. Living polymerization of different monomers by sequential additions: By adding a monomer (B) to the living polymer prepared from a monomer (A), an AB diblock copolymer, poly(A)-block-poly(B) is synthesized.
What is block polymerization?
Block copolymers are polymers containing alternating segments of different polymer compositions, linked together through their reactive ends. From: Comprehensive Nanoscience and Technology, 2011.
What is an example of block copolymer?
Block copolymers are made up of blocks of different polymerized monomers. For example, polystyrene-b-poly(methyl methacrylate) or PS-b-PMMA (where b = block) is usually made by first polymerizing styrene, and then subsequently polymerizing methyl methacrylate (MMA) from the reactive end of the polystyrene chains.
What do you mean by copolymers?
Copolymer refers to a kind of polymer that contains two or more distinct repeating units called “monomers.” It produces high molecular weight substances by chemical combination or the polymerization of monomers. It is used to produce a variety of products like plastics, tires and tubes.
What is a diblock?
A diblock copolymer is a polymer consisting of two types of monomers, A and B. The monomers are arranged such that there is a chain of each monomer, and those two chains are grafted together to form a single copolymer chain.
Why copolymers are synthesized?
The synthesis of alternating copolymers enables precise placement of functional groups into the polymer backbone. Stilbene-containing alternating copolymers possess sterically congested backbones which induce interesting properties.
What are copolymers give examples?
What are Copolymers? A copolymer is a polymer that is made up of two or more monomer species. Many commercially important polymers are copolymers. Examples include polyethylene-vinyl acetate (PEVA), nitrile rubber, and acrylonitrile butadiene styrene (ABS).
Why copolymers are better than homopolymers?
Homopolymers tend to have higher crystallinity levels. Hence they have better short term mechanical properties — stiffness, tensile strength, impact resistance and initial creep resistance. Having lower crystallinity, copolymers tend to have better dimensional stability and win out on lower friction and less wear.
What are copolymers give two examples?
A copolymer is a polymer that is made up of two or more monomer species. Many commercially important polymers are copolymers. Examples include polyethylene-vinyl acetate (PEVA), nitrile rubber, and acrylonitrile butadiene styrene (ABS).
How are the moieties of a triblock copolymer formed?
This study describes the self-association behavior of a novel PEG-based amphiphilic triblock copolymer, which consists of LA/GA as hydrophobic moieties joined at the two ends of the chain. Depending on the block length and the copolymer concentration, different phase diagrams and protein release profiles were achieved.
Can a triblock copolymer undergo a reversible sol transition?
Many commercially available block copolymers, such as Pluronics or poloxamers can undergo a temperature-induced reversible gel–sol transition upon heating or cooling of the aqueous solution.
What kind of polymers are used in controlled drug release?
Thermosensitive polymers, also called “intelligent” or “smart” polymers, have met with increasing interest during the past two decades, particularly in the field of controlled drug release (Eeckman et al., 2004). With these polymers, it is possible to administer the formulation as a solution, which then gels at body temperature.