Polymers, epoxide functionalized

An alternate way to make block copolymers involving PDMS blocks 124,125) is to have these chains fitted with epoxide functions at chain end, and to react them with a vinylic or dienic polymer carrying terminal COOH functions. Sequential addition of monomers has also been used, the ring opening polymerization of the cyclic trimer (D3) being initiated by the anionic site of a living polymer126). 

The total theoretical heat of polymerization assuming conversion of all the epoxide functions to polymer was calculated to be 85 J/g. This was calculated from heats of reaction for cycloaliphatic epoxide monomers of 94.5 KJ/mol. 

A miktoarm star copolymer carrying one PS arm and two polypropylene oxide) arms126 was prepared by the method given in Scheme 56. Living PS chains were end-capped with one unit of DPE, to reduce the reactivity of the chain end, followed by the addition of epichlorohydrin to produce the epoxide functionalized polymer. It was shown by SEC analysis and chemical titration that the epoxide content of the final product was 95 wt %. The desired functionalized... 

In another work, improvement of polymerization reactivity of epoxides was attempted [148]. Styrene monomers were modified with epoxide functions that are inert toward radicallic species, and then polymerized in the presence of azobisiso-butyronitrile (AIBN). The polymers, ultimately, were cross-linked by sulfonium salt induced photopolymerization of the epoxide groups (Scheme 11.45) [148]. Kinetic results indicate that polymers containing silicon in their pendant group has the highest cross-linking reactivity. 

A number of hydroxylated water soluble polymers were examined as coreactants with polymer 52 in the absence of calcium alginate, and were judged on the basis of the rate of gel formation and the physical properties of the gel These polymers included sodium alginate, polyvinyl alcohol, and copolymers of HEMA with MAA. Of the polymers tested, best results were obtained with polymer 10a, a copolymer of HEMA with a mole fraction of about 10% MAA, which rapidly produced an elastic gel on exposure to polymer 52 in solution. Simple condensation of the carboxyls in polymer 10a with the epoxide functionality was ruled out as a competing reaction due to the measurable but slow reaction between polymer 52 and poly methacrylic acid. It is, therefore, likely... 

Since there are multiple reactive sites on the epoxide-containing polymers, some crosslinked copolymer may result if the acid-containing polymer is functionalized at both ends. The proportion of crosslinked copolymer formed also depends upon blend composition and processing conditions. An example is also included in this section where a compatibilizing copolymer is postulated to form by reaction between acidic phenolic end-groups on polycarbonate and epoxide groups grafted to PP [Zhihui et al., 1997]. 

Tonhauser C, Frey H (2010) A road less traveled to functional polymers epoxide termination in living carbanionic polymer synthesis. Macromol Rapid Commun 31 1938-1947... 

Bazzar M, Ghaemy M, Alizadeh R. Novel fluorescent light-emitting polymer composites bearing 1,2,4-triazole and quinoxaline moieties reinforcement and thermal stabilization with silicon carbide nanoparticles by epoxide functionalization. Polym Degrad Stab 2012 97(9) 1690-703. 

Despite a number of investigations, the efficient synthesis of co-epoxide-functionalized polymers in hydrocarbon solution with lithium as counterion at room temperature had not been reported. Takenaka et developed an efficient synthesis of epoxide-functionalized polystyrenes and poly-isoprenes by terminating the corresponding living polymeric anions with (2-bromoethyl)oxirane at -78 °C in THE as shown in eqn [27]. Termination of either PSLi or PlLi by inverse addition to 2-3 equivalents of (2-bro-moethyl)oxirane reportedly produced the corresponding epoxy-functionalized polymers in quantitative yields as determined by NMR and TLC-FID chromatography. However, the requirements of -78 °C and THF as solvent limit the usefulness of this procedure. 

As a general overview, crucial for tailoring applications of suberin monomers in polymer synthesis, it can be concluded that Cl8, followed by C22 monomers, are the dominant aliphatic compounds and that most of them are carboxylic acids, bearing at least one aliphatic-OH functionality. Additionally, the 9,10-epoxide functionality is also very common. 

Plasticizers are typically di- and triesters of aromatic or aliphatic acids and anhydrides. Epoxidized oil, phosphate esters, hydrocarbon oils, and some other materials also function as plasticizers. In some cases, it is difficult to discern if a particular polymer additive functions as a plasticizer, a lubricant, or a flame retardant. 

Most plasticizers are used with polyvinyl chloride (PVC). Some go into such plastics as cellulosics, nylon, polyolefins, and styrenics. Plasticizers are typically di- and tri-esters of aromatic or aliphatic acids and anhydrides. Epoxidized oil, phosphate esters, hydrocarbon oils, and some other materials also function as plasticizers. In some cases, it is difficult to discern whether a particular polymer additive functions as a plasticizer, lubricant, or flame retardant. The most popular plasticizers are the phthalates, followed by the epoxies, adipates, azelates, trimeflitates, phosphates, polyesters, and others. There are a number of discrete chemical compounds within each of these categories. As a result, the total number of plasticizers available is substantial. 

Various approaches have been undertaken for reactive compatibilization of poly-amide/ABS alloys. Maleic anhydride can be grafted to the ABS. Styrene maleic anhydride (SMA) copolymers have been employed as compatibilizers for polyamide/ABS blends. SMA and SAN copolymers are miscible when the AN and maleic anhydride (MA) contents are equal. The impact strength of these blends has been found to be sensitive to the amount and composition of the SMA copolymer. Addition of SMA to SAN/polyamide blends was found to enhance the tensile and impact properties of these blends. Imidized acrylic polymers have been used as compatibilizers for nylon-6/ABS blends. Glycidyl methacrylate and methyl methacrylate (GMA/MMA) copolymers are used as compatibilizing agents. The epoxide functionality in GMA is capable of reaction with polyamide end groups. GMA/MMA copolymers can be shown to be miscible with SAN over the range of AN content of ABS. Styrene/GMA copolymers have been reported to be used as compatibilizers for polymer pairs such as... 

The epoxidation of diene-based polymers is advantageous because it provides active sites along the polymer chains for further modification. Furthermore, introducing an epoxide functional group to unsaturated polymers can help improve abrasion resistance, adhesive strength, and heat stability. Epox-idized polymers can be prepared by polymerizing epoxidized monomers however, this method typically results in many side reactions. Numerous reports have focused on the epoxidation of diene-based polymers with... 

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