Polycaprolactones polymerization

The PCL Intravaginal Insert, which is a T-shaped delivery system comprising a single-mold polycaprolactone polymeric insert impregnated with progesterone that is manufactured by injection molding at very low molding temperatures (around 80 C). 

Polycaprolactone polymerization was also performed solvent-free (bulk) in the parallel synthesizer, under similar conditions. In the absence of solvent (toluene), the reaction resulted in a viscous polymer solution that could not be stirred well by shaking. As a result, polymerization leads to low molecular weight polymers (Figure 3.7). 

Commercial end functional polymers have been converted to alkoxyamincs and used to prepare PKO-Worri-PS.040 The hydroxyl group of alkoxyamine 284 was used to initiate ring-opening polymerization of caprolactonc catalyzed by aluminum tris(isopropoxide) and the product subsequently was used to initiate S polymerization by NMP thus forming polycaprolactone-Wodr- P8.641 The alternate strategy of forming PS by NMP and using the hydroxyl chain end of the product to initiate polymerization of caprolactonc was also used. 

Surfactants are prepared which contain carboxylic acid ester or amide chains and terminal acid groups selected from phosphoric acid, carboxymethyl, sulfuric acid, sulfonic acid, and phosphonic acid. These surfactants can be obtained by reaction of phosphoric acid or phosphorus pentoxide with polyhydroxystearic acid or polycaprolactone at 180-190°C under an inert gas. They are useful as polymerization catalysts and as dispersing agents for fuel, diesel, and paraffin oils [69]. 

Preparation and characteristics of ABA type polycaprolactone-b-polydimethyl-siloxane block copolymers have been recently reported 289). In this study, ring-opening polymerization of e-caprolactone was achieved in melt, using a hydroxybutyl terminated PSX as the initiator and a catalytic amount of stannous octoate. Reactions were completed in two steps as shown in Reaction Scheme XIX. 

The neutral fats used in the preparation of the hydrophobic core of the several liposphere-vaccine formulations described here included tricaprin and tristearin, stearic acid, and ethyl stearate. The phospholipids used to form the surrounding layer of lipospheres were egg phosphatidylcholine and dimyristoyl phosphatidylg-lycerol. Polymeric biodegradable lipospheres were prepared from low molecular weight polylactide (PLA) and polycaprolactone-diol (PCL). 

All liposphere formulations prepared remained stable during the 3-month period of the study, and no phase separation or appearance of aggregates were observed. The difference between polymeric lipospheres and the standard liposphere formulations is the composition of the internal core of the particles. Standard lipospheres, such as those previously described, consist of a solid hydrophobic fat core composed of neutral fats like tristearin, whereas, in the polymeric lipospheres, biodegradable polymers such as polylactide or polycaprolactone were substituted for the triglycerides. Both types of lipospheres are thought to be stabilized by one layer of phospholipid molecules embedded in their surface. 

Composite rocket propellants are two-phase mixtures comprising a crystalline oxidizer in a polymeric fuel/binder matrix. The oxidizer is a finely-dispersed powder of ammonium perchlorate which is suspended in a fuel. The fuel is a plasticized polymeric material which may have rubbery properties (i.e. hydroxy-terminated polybutadiene crosslinked with a diisocyanate) or plastic properties (i.e. polycaprolactone). Composite rocket propellants can be either extruded or cast depending on the type of fuel employed. For composite propellants which are plastic in nature, the technique of extrusion is employed, whereas for composite propellants which are rubbery, cast or extruded techniques are used. 

Controlled block copolymerization of olefins with polar monomers was performed with a lanthanide complex by the successive polymerization of hexene (or pentene) and methylmethacrylate (or caprolactone). Polyhexene-block-poly(methyl methacrylate), polyhcxcnc-fo/ock-polycaprolactone, poly-pentene-fc/ock-poly(methyl methacrylate), and polypentene-Wock-polycapro-lactone were synthesized using a lanthanide complex as initiator [140-143]. 

Ring-Opening Polymerization Polylactic Acid, Polyglycolic Acid, and Polycaprolactone... 

Liquefaction of untreated wood can also be achieved at a lower temperature of 150°C and at atmospheric pressure in the presence of a catalyst [12]. Phenolsulfonic acid, sulfuric acid, hydrochloric acid, and phosphoric acid were used as catalysts. In this acid catalyst method, phenols and polyhydric alcohols can also be used for the coexisting organic solvents. Phenol, cresol, bisphenol A and F, and so forth are successfully adoptable as the phenols. Polyethylene glycols, polyether polyols (epoxide additionally reacted polyether polyol, polyethylene terephthalate polyol) have been found to liquify wood resulting in polyol solutions [13]. Liquefaction of wood in the presence of -caprolactone, glycerin, and sulfuric acid has also been accomplished. It was confirmed in this case that liquefaction and polymerization, the latter of which produces polycaprolactone, take place in the reaction system at the same time [14]. Besides the wood material, it has become apparent that trunk and coconut parts of palm, barks, bagasse, coffee bean wastes, and used OA papers can also be liquified [15]. 

A similar approach uses the co-polymerization of ethylene with 5-ethylidene-2-norbornene, followed by hydroboration/oxidation of the unreacted vinyl group. The hydroxylic functions in the co-polymer are then converted into -OAlEt2 groups and used as catalysts for -caprolactone polymerization, thus leading to poly(ethylene-fo-ENB)-graft-polycaprolactone co-polymers.600... 

Examples of high polydispersity ratios and bimodal distributions have been previously rationalized by heterogeneous reaction conditions. Tirrell et al.(19) found Mw/Mn values well over 2.0 and low molecular weight shoulders in slow, low temperature RIM polymerized urethanes based on polycaprolactone diols. Xu et al. 

The divalent samarium complex 159 was studied as an initiator in the polymerization of -caprolactone (Scheme 8) [98]. The catalytic reactions at room temperature within 1 h afforded the corresponding polycaprolactones in high yields (92-95%). A strong dependence of the polymer molecular weights on the concentration of... 

The extruder can be used for a variety of polymerizations even if no preformed polymer is present.89 These include the continuous anionic polymerization of caprolactam to produce nylon 6,90 anionic polymerization of capro-lactone 91 anionic polymerization of styrene 92 cationic copolymerization of 1,3-dioxolane and methylal 93 free radical polymerization of methyl methacrylate 94 addition of ammonia to maleic anhydride to form poly(succin-imide) 95 and preparation of an acrylated polyurethane from polycaprolactone, 4,4 -methylenebis(phenyl isocyanate), and 2-hydroxyethyl acrylate.96 The technique of reaction injection molding to prepare molded parts is slightly different. Polyurethanes can be made this way by... 

Immobilized CALB has frequently been applied in the literature as a catalyst for polymerization of aliphatic polyesters, polycarbonates, polyurethanes and their copolymers. In the present work on CALB catalyzed polymerization, the ring opening of e-caprolactone to polycaprolactone was selected as the model polymerization reaction (Figure 3.3). This model reaction has been well established in the literature [24-27] as an example of a polymerization reaction that can be successfully catalyzed by immobilized lipases (see also Chapter 4). Polymer synthesis and characterization was performed in four steps (i) polymerization (ii) separation (iii) purification and (iv) characterization. 

Figure 3.3 Ring opening polymerization of e-caprolactone to polycaprolactone (PCL).

Compatible Polyblends. When the polymeric materials are compatible in all ratios, and/or all are soluble in each other, they are generally termed polyalloys. Very few pairs of polymers are completely compatible. The best known example is the polyblend of polyCphenylene oxide) (poly-2,6-dimethyl-l,4-phenylene oxide) with high-impact polystyrene (41). which is sold under the trade name of Noryl. It is believed that the two polymers have essentially identical solubility parameters. Other examples include blends of amorphous polycaprolactone with poly(vinyl chloride) (PVC) and butadiene/acrylonitrile rubber with PVC the compatibility is a result of the "acid-base" interaction between the polar substituents (1 ). These compatible blends exhibit physical properties that are intermediate to those of the components. 

U.S. Pat. No. 6,274,652 [127] discloses a biodegradable composite material comprising bacterial cellulose in a powdery state and a polymeric material such as poly-hydroxybutyrate, polyhydroxyvalerate, polycaprolactone, polybutylenesuccinate, polyethylenesuccinate, polylactic acid, polyvinylalcohol, cellulose acetate, starch, and other biodegradable polymers. 

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