Polyesters functionalized polymers

Terminal-functionalized polymers such as macromonomers and telechelics are very important as prepolymer for construction of functional materials. Single-step functionalization of polymer terminal was achieved via lipase catalysis. Alcohols could initiate the ring-opening polymerizahon of lactones by lipase catalyst. The lipase CA-catalyzed polymerizahon of DDL in the presence of 2-hydroxyethyl methacrylate gave the methacryl-type polyester macromonomer, in which 2-hydroxyethyl methacrylate acted as initiator to introduce the methacryloyl group quanhtatively at the polymer terminal ( inihator method ).This methodology was expanded to the synthesis of oo-alkenyl- and alkynyl-type macromonomers by using 5-hexen-l-ol and 5-hexyn-l-ol as initiator, respechvely. 

In vitro synthesis of polyesters using isolated enzymes as catalyst via non-biosynthetic pathways is reviewed. In most cases, lipase was used as catalyst and various monomer combinations, typically oxyacids or their esters, dicarboxylic acids or their derivatives/glycols, and lactones, afforded the polyesters. The enzymatic polymerization often proceeded under mild reaction conditions in comparison with chemical processes. By utilizing characteristic properties of lipases, regio- and enantioselective polymerizations proceeded to give functional polymers, most of which are difficult to synthesize by conventional methodologies. 

End-functional polymers were also synthesized by lipase-catalyzed polymerization of DDL in the presence of vinyl esters [103,104]. The vinyl ester acted as terminator ( terminator method ). In using vinyl methacrylate (12.5 mol % or 15 mol % based on DDL) and lipase PF as terminator and catalyst, respectively, the quantitative introduction of methacryloyl group at the polymer terminal was achieved to give the methacryl-type macromonomer (Fig. 12). By the addition of divinyl sebacate, the telechelic polyester having a carboxylic acid group at both ends was obtained. 

Keywords Aliphatic polyester Biodegradable polymer Functionalized polymer Lactone Living polymerization Macromolecular engineering Ring-opening... 

Blanquer S, Tailhades J, Darcos V, Amblard M, Martinez J, Nottelet B, Coudane J (2010) Easy synthesis and ring-opening polymerization of 5-Z-Amino-8-valerolactone new degradable amino-functionalized (co)polyesters. J Polym Sci A Polym Chem 48 5891-5898... 

Phenolic, epoxy, urea, melamine, and polyester (alkyd) polymers are cross-linked (thermoset) plastics. They are solvent-resistant and are not softened by heat. Unlike the thermoplastic step reaction polymers, which are produced by the condensation of two difunctional reactants, these network polymers are produced from reactants at least one of which has a degree of functionality higher than two. 

There is considerable promise for the synthesis of useful functionalized fluorocarbon materials using other direct fluorination techniques (46), such as the fluorination of pendant polyesters and polymers containing pendant acyl fluoride units. 

The saturated analogue of MDI, 4,4 -dicy-clohexyl methane diisocyanate, has found limited use as an aiphatic isocyanate in adhesives. This material is known by a variety of names including Desmodur W (Bayer), hydrogenated MDI (or HMDI or Hl2MDI), reduced MDI (RMDI), and saturated MDI (SMDI), It is a low-viscosity liquid with a fairly high vapor pressure, so it too must be handled with care. In adhesive compositions, the diisocyanate usually is used to make an isocyanate functional prepolymer by reacting excess diisocyanate with a hydroxyl or amine functional polymer such as a polyester diol. 

An example of the type of condensation polymers which could be synthesized is the polyester condensation polymer of controlled molecular weight and terminal functionality illustrated in the following equation (10) ... 

In order to introduce a functional group, a first route is based on the conversion of polyesters or polymers bearing pendant ester groups into the corresponding polyenolates, followed by reaction with a judiciously substituted electrophile. A second strategy is the direct polymerization of an acrylate or a methacrylate substituted by a functional group. 

Apart from natural materials, oxidoreducates have been used to modify synthetic polymers. For example, using peroxidase, poly(4-hydroxystyrene) has been functionalized with aniline while poly(p-phenylene-2,6-benzobisthiazole) has been rendered more hydrophilic [22, 23]. Other authors have demonstrated that phenolics can be covalently bound to amino-functionalized polymers by using laccase resulting in increased fire resistance [13]A large number of scientific reports are available on enzymatic functionalization of poly(alkyleneterephthalate)s. Polyester fibers account for 73% of all synthetic fibers on the market with an annual production of approx. 27 million tons [24]. Similarly, polyamides and polyacrylonitriles have significant market shares. In contrast to natural polymers discussed above, hydrolases have shown higher potential for modification of these synthetic materials than oxidoreducates. 

Many different NLO chromophore-functionalized polymers have been investigated, including polymethacrylates, polystyrenes, poly(acrylamides), polyurethanes (PU), polyquinolines, polyesters, polyethers, and polyamides [4,70,71]. In the next sections, more attention will be paid to high-7g polymers such as polyimides and polycarbonates. 

Alditols polyols are readily renewable, inexpensive and harmless to the environment. By incorporation of polyols into aliphatic polyesters, functional linear or hyperbranched polymers can be prepared with specific biological activities and/or that respond to environmental stimuli. Polyesters with carbohydrate or polyol repeat units in chains have been prepared by chemical methods. " In some cases, the reaction conditions led to hyperbranched polymers (HBPs). The highly branched architecture of HBPs leads to unusual mechanical, rheological and compatibility properties. " These distinguishing characteristics have garnered interest for their use in numerous industrial and biomedical fields. Chemical routes to linear polyol-polyesters require elaborate protection-deprotection steps ". Furthermore, condensation routes to hyperbranched polymers generally require harsh reaction conditions such as temperatures above 150 C and highly acidic catalysts ". ... 

Condensation polymers are classified as polyesters, polyamides, polyurethanes, and ether polymers, based on the internal functional group being ester (-COO-), amide (-CONH-), urethane (-OCONH-), or ether (-0-). Another group of condensation polymers derived by condensation reactions with formaldehyde is described under formaldehyde resins. Polymers with special properties have been classified into three groups heat-resistant polymers, silicones and other inorganic polymer, and functional polymers. Discussions in all cases are centered on important properties and main applications of polymers. 

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