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This research paper describes a general method to synthesize functional polymers using a combination of atom transfer radical polymerization and hydrosilation. Methyl methacrylate (MMA) was copolymerized with (4-vinylphenyl)dimethylsilane (VPDS) in toluene via atom transfer radical polymerization (ATRP). The presence of a silyl hydride bond was proven using MALDI-ToF, NMR and IR spectra. The ability of the copolymer to undergo hydrosilation reaction was confirmed by reacting it with allyl alcohol. The expected molecular weight increase of the final polymer after functionalization was in agreement with the observed molecular weight. This method can be used to control both the type and quantity of functionalization by varying the amount of VPDS in the monomer feed.

An efficient method for the synthesis of well-defined cyclic polystyrenes using anionic polymerization, silicon chloride linking chemistry, and metathesis ring closure has been developed. The macrocycle precursor, α,ω-bis(4-pentenyl)polystyrene, was formed by 4-pentenyllithium-initiated polymerization of styrene, coupling of α-pentenylpoly(styryl)lithium (PLi) with dimethyldichlorosilane to form α,ω-bis(4-pentenyl)polystyrene (Mn = 4600 g mol−1) and reaction of excess PLi with ethylene oxide to facilitate purification. Cyclization of the purified α,ω-bis(4-pentenyl)polystyrene was performed in dichloromethane under mild conditions using a Grubbs catalyst, bis(tricyclohexylphosphine)benzylidine ruthenium(IV) chloride, as a metathesis ring-closure agent. In contrast to prior work, no fractionation is required to obtain the pure product. Both the divinyl precursor and resulting macrocycle were characterized by SEC, MALDI-TOF mass spectrometry (MS) and NMR. The macrocycle was unambiguously distinguished from its precursor using the fragmentation patterns from tandem mass spectrometry (MS2) experiments. The results show that the macrocyclic precursor, α,ω-bis(4-pentenyl)polystyrene, was of high purity and that the cyclization was highly efficient.

A series of [60]fullerene (C60)-containing poly(ethylene oxide)-block-polystyrene (PEO-b-PS) with various numbers and different locations of C60 along the polymer chains were designed and synthesized via a combination of “click” chemistry and living/controlled polymerization techniques such as anionic polymerization, atom transfer radical polymerization, and reversible addition–fragmentation chain transfer polymerization. One C60 was tethered either to the end of a PS block (PEO-b-PS-C60) or at the junction point between PS and PEO blocks [PEO-(C60)-PS]; while multiple C60s could be attached randomly along the PS block (PEO-b-PS/C60). The reaction conditions were carefully controlled to ensure a quantitative C60 functionality at precise locations in the case of PEO-b-PS-C60 and PEO-(C60)-PS and to avoid crosslinking in the synthesis of PEO-b-PS/C60. The results have implications in the precision synthesis of fullerene polymers in general. These C60-containing diblock copolymers possess different composition, diverse architecture, and high fullerene functionality. They can serve as model “shape amphiphiles” for the construction of complex hierarchical structures via the interplay between C60–C60 aggregation and block copolymer self-assembly/micro-phase separation.

This paper reports the design and synthesis of fluoroalkyl-functionalized polyhedral oligomeric silsesquioxane (FPOSS)-based shape amphiphiles with two distinct topologies: (i) mono-tethered FPOSS-poly(e-caprolactone) (PCL) and (ii) FPOSS tethered with two polymer chains possessing different compositions, namely, polystyrene (PS) and PCL, denoted as PS–(FPOSS)–PCL. The synthetic strategy features an efficient “growing-from” and “click-functionalization” approach. From a monohydroxyl-functionalized heptavinyl POSS, a PCL chain was grown via ring opening polymerization (ROP) of e-caprolactone; subsequent thiol–ene “click” chemistry with 1H,1H,2H,2H-perfluoro-1-decanethiol allowed the facile introduction of seven perfluorinated alkyl chains onto the POSS head. Similarly, PS–(FPOSS)–PCL was synthesized from a PS precursor bearing both hydroxyl group and heptavinyl POSS at the ω-end, which was prepared by living anionic polymerization and hydrosilylation. The compounds were fully characterized by 1H NMR, 13C NMR, FT-IR spectroscopy, MALDI-TOF mass spectrometry, and size exclusion chromatography. The introduction of perfluorinated molecular cluster into polymers is expected to make them surface-active while the interplay between crystallization and fluorophobic/fluorophilic bulk phase separation in these shape amphiphiles shall lead to intriguing self-assembly behavior and novel hierarchical structures. This study has demonstrated FPOSS as a versatile building block in the construction of shape amphiphiles and established a general and efficient method to introduce such fluorous molecular clusters into polymers.

The relative stabilities of several methoxycarbenium ions have been determined directly via a stepwise equilibration method.