A series of organic/inorganic hybrid block and random copolymers were prepared by reversible addition− fragmentation chain transfer (RAFT) polymerization using poly-(ethylene glycol) methyl ether methacrylate (PEGMA) and 3- (3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.1 3,9 .1 5,15 .1 7,13 ]octasiloxane-1-yl)propyl methacrylate (MA-POSS) as monomers in order to study the effect of polymer morphology and POSS content on the properties of polymer electrolytes. Flexible and dimensionally stable free-standing films were made from the hybrid block and random copolymers mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) when the contents of MA-POSS unit were larger than 31 and 16 mol %, respectively. The ionic conductivity of the solid-state block copolymer (PBP) electrolyte was found to be 1 order of magnitude higher than that of the random copolymer (PRP) electrolyte when they had similar MA-POSS content, although their glass transition temperature values of their ion-conducting segments were quite close. Moreover, the ionic conductivity of the PBP electrolyte was not much different from that of the wax state poly(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) electrolyte. For example, the ionic conductivity values for the PBP electrolyte containing 31 mol % of MA-POSS, the PRP electrolyte containing 29 mol % of MA-POSS, and P(PEGMA) electrolyte were 2.05 × 10 −5 , 3.00 × 10 −6 , and 4.23 × 10 −5 S cm −1 , respectively, at 30 °C. The large ionic conductivity value of the block copolymer electrolyte is ascribed to the nanophase separation forming the ion-conducting channels.

A series of organic/inorganic hybrid star‐shaped polymers were synthesized by atom transfer radical polymerization using 3‐(3,5,7,9,11,13,15‐heptacyclohexyl‐pentacyclo[9.5.1.13,9.15,15.17,13]‐octasiloxane‐1‐yl)propyl methacrylate (MA‐POSS) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) as monomers and octakis(2‐bromo‐2‐methylpropionoxypropyldimethylsiloxy)octasilsesquioxane as an initiator. Star‐shaped polymers with methyl methacrylate (MMA) and PEGMA moieties were also prepared for comparison purposes. Dimensionally stable freestanding film could be obtained from the hybrid star‐shaped polymer containing 26 wt % of MA‐POSS moieties although its glass transition temperature is very low, −60.9 °C. As a result, the hybrid star‐shaped polymer electrolyte containing lithium bis(trifluoromethanesulfonyl)imide showed ionic conductivities (1.75 × 10−5 S/cm at 30 °C), which were two orders of magnitude higher than those of the star‐shaped polymer electrolyte with MMA moieties. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

ArF photoresist polymers were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization and free radical polymerization (FRP). Three methacrylates with lithographic functionalities including 2-ethyl-2-adamantyl methacrylate (EAdMA), α-gamma-butyrolactone methacrylate (GBLMA), and 3-hydroxy-1-adamantyl methacrylate (HAdMA), were used as monomer components and 2-cyanoprop-2-yl-1-dithionaphthalate (CPDN) was used as the chain transfer agent (CTA). In both polymerizations, the order of monomer reactivity was GBLMA>HAdMA>>EAdMA. This caused a composition gradient in RAFT polymerization as well as composition inhomogeneity in FRP. The polymers prepared by RAFT polymerization had lower molecular weight distributions and more uniform compositions. The improvement in molecular weight distribution and composition uniformity of the polymers prepared by RAFT polymerization should be beneficial for the ArF lithography process.

A series of branched polymers for chemically amplified resists (CARs) were prepared through the reversible addition–fragmentation chain‐transfer (RAFT) copolymerization of three monomers with lithographic functionalities and an acid‐cleavable dimethacrylate monomer. The three monomers with lithographic functionalities were 2‐ethyl‐2‐adamantyl methacrylate, α‐γ‐butyrolactone methacrylate, and 3‐hydroxy‐1‐adamantyl methacrylate. The acid‐cleavable monomer was 2,5‐dimethyl‐2,5‐hexanediol dimethacrylate (DMHDMA), and 2‐cyanoprop‐2‐yl‐1‐dithionaphthalate was used as a chain‐transfer agent. Because DMHDMA contains two methacrylate groups, it induced the branched structures of the polymers. The degree of branching could be controlled by the molar fraction of DMHDMA in the monomer mixtures. The size and structure of the polymers obtained after hydrolysis were very close to those of linear polymers prepared by RAFT copolymerization with the same amount of reagents, only without the acid‐cleavable monomer. A preliminary lithography test using an argon fluoride source demonstrated that the acid‐cleavable branched polymers could be promising candidates for CAR materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

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