Block copolymers and networks from polybutadiene and polydiethylsiloxane

Abstract

Di‐, tri‐, and star block copolymers from polybutadiene (PB) and polydiethylsiloxane (PDES) have been synthesized by sequential anionic polymerization, using mono‐, di‐, and tetrafunctional terminating agents. The tri‐ and star block copolymers were crosslinked by hydrosilylation of the PB double bonds with chlorodimethylsilane, followed by condensation of the chlorosilane groups with ambient humidity. The thus obtained rubbers showed elastomeric tensile behavior and stressinduced mesophase formation. Both the block copolymers and the rubbers showed microphase separation into PB and PDES domains.

Applications of Hybrid Polymers Generated from Living Anionic Ring Opening Polymerization

“…A second potential solution is star block polymers generated by AROP, which provide a mechanism through which the non-siloxane block can dominate interfacial behavior [ 52 ]. The reviewers note that similar morphologies have also been reported for polybutadiene-polydiethylsiloxane block copolymers (PBD-b-PDES) [ 19 ]; these copolymers possess less differentiation in surface energy, potentially mitigating issues with the styrenic and methacrylate systems, but have not been evaluated in lithographic systems. Similarly noteworthy in this context, while the synthesis of diblock polymers typically starts with an organic macroanion and then proceeds to a siloxane polymerization, the potential of the reverse process, in which a siloxane macromer starts and proceeds to an acrylate polymerization, was demonstrated using ATRP [ 177 ].…”

“…Molenberg also reported on elastomeric block polymers of butadiene and diethylsiloxane that exhibited mesophase formation under tensile stress [ 19 ]. Later work with styrene-diethylsiloxane diblock polymers showed periodic nanoscale lamellar structures with compositions possessing greater than 20% styrene content, as shown in Figure 17 [ 42 ].…”

“…Bulk structures of ( a ) PS- b -PDES containing 37 wt% PS and ( b ) PS- b -PDES containing 43 wt% PS (Reprinted with permission from Ref. [ 19 ] Copyright 1998 Wiley).…”

“…The fact that there are only five monomeric building blocks for the living AROP-derived polymers that represent virtually all commercial applications as well as the vast majority of published reports is a consequence both of practical synthetic routes [ 16 , 17 , 18 ] and the sluggish rates of polymerization reported for cyclotrisiloxanes with greater organic substitution [ 19 ]. A preparation has been reported [ 20 ] for the simple and highly desirable monomer trimethylcyclotrisiloxane, but its practical isolation has not yet been described.…”

Amphiphile polydimethylsiloxane‐based networks reinforced with in situ generated silica

“…However, this amphiphile network is reinforced with silica, which limits the swelling capacity both in polar (water) and in nonpolar (chloroform) solvents: 0.5–58.5 and 123.8–0.8%, respectively. For simple comparison, for networks based on the polybutadiene–polydiethylsiloxane copolymers crosslinked by siloxane bonds, the reported swelling capacity in toluene was in the range 310–1300%, depending on the copolymer composition [19].…”