Synthesis and real-time 1 H NMR kinetic studies on the living anionic copolymerization of 4-trimethylsilylstyrene (4TMSS), an electronically intricate monomer, are reported. Statistical copolymers of 4TMSS with styrene (S) and isoprene (I) with M n up to 50 kg mol −1 were synthesized and analyzed with respect to dispersity, comonomer composition, and glass-transition temperatures, T g . Access to well-defined di-and triblock copolymers ensured comprehensive synthetic control. Real-time 1 H NMR kinetic measurements unraveled an enthralling gradient microstructure (r 4TMSS = 2.76; r S = 0.087 and r I = 3.28; r 4TMSS = 0.15) in the copolymers. The sequence distribution provided by a tandem MALDI-MS 2 study validated an enhanced reactivity of 4TMSS in comparison to styrene in cyclohexane at room temperature. Furthermore, the kinetics of 4TMSS homopolymerization revealed detailed mechanistic insights. The possibility to tailor T g and hydrophobicity of the copolymers by varying the 4TMSS content provides a promising approach to design copolymer-based materials for high-end applications, for example, in gas separation membranes.

A facile synthesis using a Grignard reaction was employed to prepare the silicon containing functional monomer 4-allyldimethylsilylstyrene (4ADSS). Detailed studies regarding the living nature of anionic polymerization of 4ADSS and its polymerization via the styrene vinyl bond in cyclohexane at room temperature were conducted, and P4ADSS samples with M n up to 80 kg mol–1 were accessible. This evidences that the 4ADSS structure disables undesired proton transfer side reactions, as known for the carbon-based analogue functional monomer 4-but-3-enyl-styrene. Real-time 1H NMR kinetics of the statistical copolymerization of 4ADSS with styrene (r 4ADSS = 3.55; r S = 0.047) revealed a remarkable gradient microstructure in the resulting copolymers. Based on this observation, a library of well-defined gradient copolymers P(4ADSS-co-S) with M n in the range of 5–50 kg mol–1 was synthesized, varying 4ADSS content. A comprehensive discussion regarding the glass transition temperatures (T g) of the synthesized homo- and copolymers is presented. Furthermore, thiol–ene click reactions at the pendant allyl moiety of P(4ADSS-co-S) were explored to introduce functional groups. Likewise, P(4ADSS-co-S) copolymers were subjected to hydrosilylation reactions, and the impact of the introduced siloxane moieties on the glass transition of the resulting copolymers is presented. Both thiol–ene reactions as well as hydrosilylation of the P(4ADSS-co-S) copolymers proceeded quantitatively. Consequently, copolymerization of 4ADSS provides access to a wide range of polystyrene-based functional materials with specific applications using versatile post-polymerization chemistry.

Motivated by the need for sustainable, bio-based materials, the living anionic polymerization of the under-explored terpene monomer β-ocimene (Oc) was investigated for the first time. Homopolymers with M n up to 50 kg mol −1 of the Oc isomeric mixture (E:Z = trans:cis = 70:30) were synthesized in cyclohexane and analyzed with respect to molecular weight control, dispersity, microstructure, and glass transition temperature, T g . Employing styrene as a comonomer, diblock copolymers, and a series of statistical copolymers with M n up to 20 kg mol −1 with varying comonomer compositions offered the opportunity to tailor the glass transition of the copolymers. Real-time 1 H nuclear magnetic resonance (NMR) kinetics indicated a remarkably divergent reactivity of the trans and cis isomers. This unveiled the unique observation that the homopolymerization of Oc is in fact a copolymerization of the cis and trans isomers, which one might name as "stereo-copolymerization" (r trans = 3.16; r cis = 0.32). Kinetic studies of the statistical copolymerization of the Oc isomeric mixture with styrene revealed an astonishingly contradictory reactivity of the two isomers (r trans < r cis ). The reactivity differences of the cis and trans isomers in the polymerization were utilized to isolate the individual isomers for the first time. Subsequently, they were independently homo-and copolymerized with styrene. The complex mechanism of these polymerizations and the rather high polymer dispersities (Đ ≈ 1.6−2) are discussed using various kinetic models supported by density functional theory modeling. The surprisingly different behavior of the two isomers with styrene was validated experimentally via a 1 H NMR-monitored chemical titration.