What is graft copolymerization?

Graft copolymer is a type of copolymer in which one or more blocks of homopolymer are grafted as branches onto a main chain, meaning it is a branched copolymer with one or more side chains of a homopolymer attached to the backbone of the main chain.

How are block copolymers synthesized?

Block copolymers are normally prepared by controlled polymerization of one monomer, followed by chain extension with a different monomer(1) to form AB or ABC block copolymers.

What is tri block copolymers?

The symmetric triblock copolymers consisting of two type of polymers (A, hydrophobic polymer and B, hydrophilic polymer) could be also classified as ABA and BAB triblock copolymers. The asymmetric triblock copolymers (ABC triblock copolymers) consisted of three different types of polymers.

What are block copolymer micelles?

Block copolymer micelles are generally formed by the self-assembly of either amphiphilic or oppositely charged copolymers in aqueous medium. The hydrophilic and hydrophobic blocks form the corona and the core of the micelles, respectively.

What are block and graft copolymers?

November 27, 2018 Posted by Madhu. The key difference between block and graft copolymer is that a block copolymer has blocks of repeating units whereas a graft copolymer has branches of repeating units. A polymer is a macromolecule that has many repeating units linked to each other via covalent chemical bonds.

What is a block co polymer?

A block copolymer is defined as a polymer comprising molecules in which there is a linear arrangement of blocks, a block being defined as a portion of a polymer molecule in which the monomeric units have at least one constitutional or configurational feature absent from the adjacent portions. 1, 2.

What is copolymerization example?

The process of forming polymers from two or more different monomeric units is called copolymerization. Multiple units of each monomer are present in a copolymer. The process of forming polymer Buna-S from 1, 3-butadiene and styrene is an example of copolymerization.

What are the benefits of copolymerization?

Copolymerization permits the synthesis of an almost unlimited range of polymers and is often used, therefore, to obtain a better balance of properties for the commercial application of polymeric materials. Copolymers may be synthesized by chain growth and step growth condensation polymerization processes.

What are polymeric micelles?

Polymeric micelles are nanoscopic core/shell structures formed by amphiphilic block copolymers. Both the inherent and modifiable properties of polymeric micelles make them particularly well suited for drug delivery purposes.

What is copolymer used for?

Common applications of block copolymers are in adhesives, surfactants, membranes, foams, and cosmetics. Figure 2.10. Block copolymer. Additionally a polymer that consists of large grouped blocks of each of the monomers is also considered a block copolymer.

What are homopolymers and copolymers?

If a polymer consists of only one kind of monomers then it is called a homopolymer, while a polymer which consists of more than one kind of monomers is called a copolymer.

What is copolymerization reaction?

The term ‘copolymerization’ includes the simultaneous polymerization of two or more types of monomer; however, the terms terpolymerization and multicomponent polymerization are often used to indicate polymerization of three types of monomer and three or more types of monomer, respectively.

What is copolymerization give an example?

Examples include polyethylene-vinyl acetate (PEVA), nitrile rubber, and acrylonitrile butadiene styrene (ABS). The process in which a copolymer is formed from multiple species of monomers is known as copolymerization. It is often used to improve or modify certain properties of plastics.

How do polymeric micelles work?

The functionality of polymeric micelles depends on their core–shell structure, whereby the hydrophobic core carries and protects the drug, while the hydrophilic shell supports and stabilizes the hydrophobic core in the aqueous medium and enhances the water solubility of the polymers; and this also benefits …

What are types of micelles?

Specific micelle structures include spherical micelles, cylindrical micelles, bilayer vesicles, lamellar phases, and inverse micelles [17,18,19].

What is homopolymerization and copolymerization?

What is homopolymer with example?

A polymer that is formed of the same repeating monomer unit is known as a homopolymer. These monomers may be similar in chemical composition or structure. Eg: polyethene is a homopolymer formed of the monomer unit ethylene.

What is the difference between polymerization and copolymerization?

A homopolymer is an arrangement where only one monomer is involved in the formation of the polymer. A copolymer is an arrangement where more than one monomers are involved in the formation of the polymer. When polymerization occurs in a mixture of monomers, copolymers are formed.

What is polymeric micelle?

How are polymeric micelles made?

Polymeric micelles are made up of a shell of hydrophilic polymer blocks, such as poly-ethylene glycol, and a hydrophobic polymer core, such as poly (propylene glycol). The amphiphilic block copolymers have the potential to produce nanoscale micelles via self-assembly in a specified solvent.

How to prepare block copolymers?

Block Copolymers. Block copolymers are normally prepared by controlled polymerization of one monomer, followed by chain extension with a different monomer(1) to form AB or ABC block copolymers. If you have not read the section on ” Chain Extension ” in the ” Procedures for Initiation of an ATRP ” you should return to that section if you wish…

What is the purpose of using ATRP?

When ATRP is employed to form each block in a block copolymer the composition and molecular weight and, to some extent, the PDI of each block can be independently controlled.   Multifunctional initiators can also be used in the process to prepare ABA or AB-star multi-armed block copolymers.(2,3)

Is amphiphilic block copolymer a viscoelastic or elastic material?

  Differential scanning calorimetry and dynamic mechanical analysis revealed that the amphiphilic block copolymer behaves as a viscoelastic fluid, while its corresponding multiblock copolymer is an elastic material.   This would suggest that the polystyrene domains aggregate to form chemical cross-links in the swellable gel

Can the same catalyst be used for the formation of copolymers?

  The same catalyst could be used for both the formation of the first precursor block copolymer and the chain extended multiblock copolymer as shown below.(19,20)