Ring-opening Polymerization ROP

At the same time, ring-opening-polymerization (ROP) processes, which dominated the phosphazene field for decades [38], tend now to be substituted by polycondensation reactions. These seem to be more feasible and reproducible, easier to carry out, and able to guarantee predictable MWs and MW distributions for these materials [10]. 

By using a combination of RAFT and ring opening polymerization (ROP), (polyethylene oxide) methyl ether)(polystyrene)(poly(L-lactide) 3-miktoarm star terpolymers have been successfully synthesized [182]. The synthetic approach involved the reaction of the cw-functionalized - OH group of the poly(ethylene oxide) methyl ether with maleic anhydride under conditions where only one hydroxyl group can be esterified (MPEO). The double bond... 

The high level of interest in the ring-opening polymerization (ROP) of cyclic esters (lactones) stems from the biocompatibility and biodegradability of their polymers. Resorbable aliphatic... 

The hybrid polymer 140 is generated by a thermal ring-opening polymerization (ROP) process (Scheme 10).300,301 Polymers containing three-coordinate sul-fur(IV) are generally hydrolytically sensitive even when the chloro substituents are replaced by phenoxy groups.302... 

Fig.3A-D. Use of ring-opening polymerization (ROP) for neobiopolymer synthesis A General mechanism of cationic ROP. B Okada s use of cationic ROP to generate polymers with carbohydrate substituents at the terminus. C General mechanism for anionic ROP. D Okada s application of anionic ROP to generate carbohydrate-substituted polymers... 

See also ROM polymers Ring-opening metathesis polymerization (ROMP) reaction, 20 413 Ring-opening polymerization (ROP), 24 271, 29 816-817, 23 702,... 

A similar ring-opening polymerization (ROP) with ethylene oxide forming poly(ethyl-ene oxide) forms a noncarbon backbone via a chainwise kinetic process ... 

Aliphatic polyesters occupy a key position in the field of polymer science because they exhibit the remarkable properties of biodegradability and biocompatibihty, which opens up a wide range of applications as environmentally friendly thermoplastics and biomaterials. Three different mechanisms of polymerization can be implemented to synthesize aliphatic polyesters (1) the ring-opening polymerization (ROP) of cyclic ketene acetals, (2) the step-growth polymerization of lactones, and (3) the ROP of lactones (Fig. 1). 

Previously, PLAs were obtained via condensation of lactic acid by heating and driving off water, which produced a gummy polymeric material of ill-dehned molecular weight and microstmcture [6]. Ring-opening polymerization (ROP) of dilactones, pioneered by Carothers in 1932 [7], was the hrst initiative for an... 

In addition to step and chain polymerizations, another mode of polymerization is of importance. This is the ring-opening polymerization (ROP) of cyclic monomers such as cyclic ethers, acetals, amides (lactams), esters (lactones), and siloxanes. Ring-opening polymerization is of commercial interest in a number of systems, including the polymerizations of ethylene oxide... 

Aldonolactones serve as suitable monomers for the generation of homo- and copolymers, especially through ring-opening polymerization (ROP). Among them are the carbohydrate-analogs of s-caprolactone, i.e., aldono-1,6-lactones. The first example of such derivatives and further ROP was reported by Galbis and co-workers [61], see also chapter, Synthetic polymers from readily available monosaccharides ... 

Scheme 14 Ring-opening polymerization (ROP) of acetylated aldono-1,5-lactones...

A kinetic study of the ring-opening polymerization (ROP) of trimethylene carbonate similarly afforded AG at 383 K of 101.9 kj mol-1, a value which was very close in energy to that found for the production of poly(TMC) from oxetane and C02. Hence, based on these experimental findings, the formation of polycarbonate from the oxetane and C02 coupling reaction was shown to occur via two different or concurrent pathways-that is, the intermediacy of TMC formation, and the subsequent polymerization and/or direct enchainment of oxetane and C02 (Figure 8.16). The presence of small amounts of ether linkages in the copolymer also supported this conclusion. 

In 1992, Suzuki et al. reported palladium catalyzed, ring-opening polymerization (ROP) of a cyclic carbamate. The polymerization was proposed to be an in situ multibranching process. 

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