Transcript Grafting from

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 very strong candidates for
potential applications in advanced technologies such as information storage, drug
delivery, and photonic crystals.
AB type block copolymers
Four main synthetic routes have been developed (Figure 8.1) to prepare well-defined
diblock copolymers with narrow molecular weight distribution and very low
compositional heterogeneity.
ABA
ABC
Graft copolymers
Target Structure: Linear densely grafted copolymer
Method: Functional monomer (protected),
ATRP, Deprotection, Macroinitiator, ATRP
Chemistry
Polymer 45 (2004) 8173–8179
Macromolecules 2005, 38, 702-708
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.
Aim: Stimuli-responsive Bottle-brush Polymer Macromol. Rapid Commun. 2013
Kejian Yao , Ying Chen , Jun Zhang , Clay Bunyard , Chuanbing Tang
Method
Chemistry
Ring opening metathesis polymerization (ROMP)
Synthesis of Block-Copolymer via Crossover-Chemistry in ROMP
Binder, Wolfgang Macromolecules 2009
Monofunctional Metathesis Polymers via Sacrificial Diblock Copolymers
Angew. Chem. Int. Ed. 2006, 45, 8045 –8048
“Perfect Comb” ADMET Graft Copolymers
Macromolecules 2001, 34, 6845-6849
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)