block copolymers block copolymers are a fascinating class of polymeric materials belonging to a big...

Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers is made by the covalent bonding of two or more polymeric chains that, in most cases, are thermodynamically incompatible giving rise to a rich variety of microstructures in bulk and in solution. The length scale of these microstructures is comparable to the size of the block copolymers molecules (typically 5–50 nm); therefore, the microstructures are highly coupled to the physical and chemical characteristics of the molecules. The variety of microstructures gives rise to materials with applications ranging from thermoplastic elastomers and high-impact plastics to pressure-sensitive adhesives, additives, foams, etc. In addition, block copolymers are

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Block Copolymers

Block copolymers are a fascinating class of polymeric materials belonging to a bigfamily known as ‘‘soft materials.’’ This class of polymers is made by the covalentbonding of two or more polymeric chains that, in most cases, are thermodynamicallyincompatible giving rise to a rich variety of microstructures in bulk and insolution. The length scale of these microstructures is comparable to the size of theblock copolymers molecules (typically 5–50 nm); therefore, the microstructures arehighly coupled to the physical and chemical characteristics of the molecules. Thevariety of microstructures gives rise to materials with applications ranging fromthermoplastic elastomers and high-impact plastics to pressure-sensitive adhesives,additives, foams, etc. In addition, block copolymers are very strong candidates forpotential applications in advanced technologies such as information storage, drugdelivery, and photonic crystals.

AB type block copolymers

Four main synthetic routes have been developed (Figure 8.1) to prepare well-defineddiblock copolymers with narrow molecular weight distribution and very lowcompositional heterogeneity.

Page 3: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

ABA

Page 4: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

ABC

Page 5: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Graft copolymers

Page 6: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 7: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 8: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Target Structure: Linear densely grafted copolymer

Method: Functional monomer (protected), ATRP, Deprotection, Macroinitiator, ATRP

Chemistry

Page 9: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Polymer 45 (2004) 8173–8179

Page 10: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Macromolecules 2005, 38, 702-708

Page 11: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Grafting to reactions require the coupling of individual preformed tele-functional side chain precursors to a backbone polymer with distributed complementary functionality.

Grafting through consists of the polymerization of macromonomers.

Grafting from involves preparing the precursor to the backbone polymer with monomer units that contain functionalities ultimately capable of initiating polymerization of a second monomer.

Page 12: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Aim: Stimuli-responsive Bottle-brush Polymer Macromol. Rapid Commun. 2013Kejian Yao , Ying Chen , Jun Zhang , Clay Bunyard , Chuanbing Tang

Method

Chemistry

Page 13: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 14: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Ring opening metathesis polymerization (ROMP)

Page 15: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 16: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 17: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 18: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 19: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 20: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Page 21: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Synthesis of Block-Copolymer via Crossover-Chemistry in ROMP

Binder, Wolfgang Macromolecules 2009

Page 22: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Monofunctional Metathesis Polymers via Sacrificial Diblock Copolymers

Angew. Chem. Int. Ed. 2006, 45, 8045 –8048

Page 23: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

“Perfect Comb” ADMET Graft Copolymers

Macromolecules 2001, 34, 6845-6849

Page 24: Block Copolymers Block copolymers are a fascinating class of polymeric materials belonging to a big family known as ‘‘soft materials.’’ This class of polymers

Macrocyclization of Polymers via Ring-Closing Metathesis and Azide/Alkyne-‘‘Click’’-Reactions: Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 48, 671–680 (2010)