Carbonate functional polymer synthesis

Webster, D. C., and Crain, A. L. Synthesis and Applications of Cyclic Carbonate Functional Polymers in Thermosetting Coatings, Progress in Organic Coatings (2000) 275-282. 

Limited information exists in the literature, however, on the homo- or copolymerization of vinyl ethylene carbonate, 1 (VEC or 4-ethenyl-l,3-dioxolane-2-one) for the preparation of cyclic carbonate functional polymers. A few comments regarding polymerization of VEC are given in an early patent [9], In the only reported study of the copolymerization behavior of VEC, Asahara, Seno, and Imai described the copolymerization of VEC with vinyl acetate, styrene, and maleic anhydride and determined reactivity ratios [10. Their results indicated that VEC would copolymerize well with vinyl acetate, but in copolymerizations with styrene, little VEC could be incorporated into the copolymer. VEC appeared to copolymerize with maleic anhydride, however the compositions of the copolymers was not reported. Our goal was to further explore the use of VEC in the synthesis of cyclic carbonate functional polymers. 

Olefin metathesis, an expression coined by Calderon in 1967,1 has been accurately described in Ivin and Mol s seminal text Olefin Metathesis and Metathesis Polymerization as the (apparent) interchange of carbon atoms between a pair of double bonds (ref. 2, p. 1). This remarkable conversion can be divided into three types of reactions, as illustrated in Fig. 8.1. These reactions have been used extensively in the synthesis of a broad range of both macromolecules and small molecules3 this chapter focuses on acyclic diene metathesis (ADMET) polymerization as a versatile route for the production of a wide range of functionalized polymers. 

There have been very few reports of polysilanes containing a carbon functional group such as unsaturated groups directly attached to the silicon main chain. This appears to be due to the difficulties in synthesis and characterization due to instability of these compounds. These polymers are expected to show significant differences to conventional polysilanes in their properties due to the interaction of main-chain cr-electron and side-chain 7r-electron systems. 

The copolymers of carbon monoxide with olefins are of considerable importance from several different standpoints. These include the low price and ready availability of carbon monoxide, the enhanced photodegradability of the copolymers, and their easy chemical conversion to other classes of functionalized polymers. This review summarizes the chemistry involved in the synthesis, characterization, degradation and the derivatization of the copolymers. In addition, work on the spectral characterization of the copolymers have been cited. 

More industrial polyethylene copolymers were modeled using the same method of ADMET polymerization followed by hydrogenation using catalyst residue. Copolymers of ethylene-styrene, ethylene-vinyl chloride, and ethylene-acrylate were prepared to examine the effect of incorporation of available vinyl monomer feed stocks into polyethylene [81]. Previously prepared ADMET model copolymers include ethylene-co-carbon monoxide, ethylene-co-carbon dioxide, and ethylene-co-vinyl alcohol [82,83]. In most cases,these copolymers are unattainable by traditional chain polymerization chemistry, but a recent report has revealed a highly active Ni catalyst that can successfully copolymerize ethylene with some functionalized monomers [84]. Although catalyst advances are proving more and more useful in novel polymer synthesis, poor structure control and reactivity ratio considerations are still problematic in chain polymerization chemistry. 

Here, we shall focus on ruthenium-catalyzed nucleophilic additions to alkynes. These additions have the potential to give a direct access to unsaturated functional molecules - the key intermediates for fine chemicals and also the monomers for polymer synthesis and molecular multifunctional materials. Ruthenium-catalyzed nucleophilic additions to alkynes are possible via three different basic activation pathways (Scheme 8.1). For some time, Lewis acid activation type (i), leading to Mar-kovnikov addition, was the main possible addition until the first anfi-Markovnikov catalytic addition was pointed out for the first time in 1986 [6, 7]. This regioselectiv-ity was then explained by the formation of a ruthenium vinylidene species with an electron-deficient Ru=C carbon site (ii). Although currently this methodology is the most often employed, nucleophilic additions involving ruthenium allenylidene species also take place (iii). These complexes allow multiple synthetic possibilities as their cumulenic backbone offers two electrophilic sites (hi). 

However, less conjugated monomers such as vinyl acetate, vinyl chloride, and ethylene are still difficult to polymerize in a controlled way by metal-catalyzed polymerizations. This is most probably due to the difficulty in activation of their less reactive carbon-halogen bonds. The following sections will discuss these aspects from the viewpoint of the monomers listed in Figure 11. Functional monomers will be discussed later in another section, Precision Polymer Synthesis. 

Yu, F. Zhuo, R. Synthesis, characterization, and degradation behaviors of end-group-functionalized poly(trimethylene carbonate)s. Polym. J. 2003, 35 (8), 671-676. 

One of the most widely used methods for the synthesis of cyclic polymers of controlled size and narrow dispersity is based on the end-to-end chain coupling of a,co-difunctional linear polymer precursors in highly dilute reaction conditions. This method offers a series of significant advantages it may be used both for polymers with in-chain reactive functions and for systems having no functional groups in their backbone such as saturated carbon-carbon bond polymers. The absence of potentially... 

Carbon-based polymer nano composites represent an interesting type of advanced materials with structural characteristics that allow them to be applied in a variety of fields. Functionalization of carbon nanomaterials provides homogeneous dispersion and strong interfacial interaction when they are incorporated into polymer matrices. These features confer superior properties to the polymer nanocomposites. This chapter focuses on nanodiamonds, carbon nanotubes and graphene due to their importance as reinforcement fillers in polymer nanocomposites. The most common methods of synthesis and functionalization of these carbon nanomaterials are explained and different techniques of nanocomposite preparation are briefly described. The performance achieved in polymers by the introduction of carbon nanofillers in the mechanical and tribological properties is highlighted, and the hardness and scratching behavior of the nanocomposites are also discussed. 

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