RAFT Copolymerization of Styrene and Maleic Anhydride with Addition of Ascorbic Acid at Ambient Temperature

Abstract

A novel method for RAFT copolymerization of styrene (St) and maleic anhydride (MAh) at ambient temperature using ascorbic acid (Asc) as an initiator is reported. Various experimental conditions including reaction component, monomer composition, the amount of Asc, and temperature were investigated in terms of monomer conversion, molecular weight, and molecular weight distribution. In this system, the copolymer of styrene/maleic anhydride (SMA) with well-regulated molecular weight and low molecular weight distribution (Mw/Mn=1.30) was obtained, and the conversion of monomer was 70.4% after 12 hours at 25°C. The NMR spectra demonstrated that the copolymer synthesized possesses a strictly alternating structure. Furthermore, the proposed mechanism adapted to the RAFT copolymerization of St and MAh initiated by Asc at ambient temperature is presented. Using this new methodology, it is possible to achieve well-defined SMA under mild conditions by RAFT copolymerization.

Through-Space Charge-Transfer Thermally Activated Delayed Fluorescence Alternating Donor–Acceptor Copolymers for Nondoped Solution-Processable OLEDs

“…RAFT copolymerization using DDMAT as a chain-transfer agent and AIBN as initiator was chosen as a method to obtain donor–acceptor alternating copolymers due to the high efficiency of this system in controlling the radical copolymerization of a wide range of monomers. , In addition, this technique allowed us to prepare well-defined homopolymers from D1 and D2 with controlled molecular weight (up to M n = 20,000 g mol –1 ) and relatively low polydispersity ( Đ < 1.5) . The copolymerization of synthesized donor and acceptor monomers proceeded at a much faster rate than the homopolymerization of the corresponding donor monomer, which is consistent with the concept of charge-transfer-complex (CTC) formation. ,,, In fact, the rate of copolymerization of D1 and A1 is about 12 times higher than that of homopolymerization of D1 : k p, app = 6.16 and 0.51 h –1 for copolymerization and homopolymerization, respectively (Figure a).…”

“…On the other hand, with rare exceptions, these polymers were synthesized using a conventional radical polymerization technique that results in high polydispersity and significant structural heterogeneity from one polymer chain to another or by ring-opening metathesis polymerization leading to the contamination of polymers by heavy metal. − Aiming at overcoming the above-mentioned limitations of TADF polymers, we proposed a new synthetic strategy toward TSCT polymers consisting of the preparation of alternating donor–acceptor copolymers with a nonconjugated structure, where donor ( D ) and acceptor ( A ) side groups will be located close enough to enable through-space π–π interaction between them. It is known that perfectly alternating copolymers could be easily obtained through the copolymerization of styrenes as donor monomers with maleic anhydride or N-substituted maleimides as acceptor monomers as a result of the specific interaction between these monomers leading to the formation of a charge-transfer complexes. − Alternating copolymerization of styrene–maleimide pairs could be performed in a living fashion by exploiting the reversible addition–fragmentation chain-transfer (RAFT) mechanism, giving access to well-defined copolymers without any contamination by traces of metals. − …”

Співполімери Малеїнового Ангідриду І Стиролу Та Іонообмінні Плівочні Матеріали На Їх Основі

“…Останніми роками зростає інтерес до розробки методів синтезу SMA та аналогів, що дозволяють контролювати будову і довжину макромолекулярних ланцюгів. У цьому напряму метою досліджень є визначення впливу умов полімеризації на макромолекулярну структуру співполімерів, контроль молекулярної маси (ММ), молекулярно-масовий розподіл, кінетику процесу [3][4][5][6], гідрофільно-гідрофобні властивості полімерів [7].…”

Influence of RAFT Agent on the Mechanism of Copolymerization of Polypropylene Glycol Maleinate with Acrylic Acid

“…Reactions between reactive macroradicals with a chain transfer agent enable the formation of a new potential center for subsequent chain growth. Thus, the polymerizing system contains both growing macroradicals and "dormant" macromolecules, which at a certain moment can split off the radical and continue the growth of the polymer chain, which together gives rise to the so-called "pseudo-living" polymerization process [11,12].…”