E-caprolactone monomer

H,3H,5H-Oxazolo [3,4-c] oxazole-7a(7H)-methanol Oxazolo [3,4-c] oxazol-7a-yl-methanol. See Hydroxymethyl dioxoazabicyclooctane 2-Oxepanone. See e-Caprolactone monomer Oxidation base 33. Seel-Naphthol Oxide of chromium. See Chromium oxide (ic)... 

Ponolith Supra Blue RB Liq. Calcitem UV E-Caprolactone monomer... 

Pivalyl valone Pivalyn. See Pivalyl indandione Pix . See Mepiquat chloride PLA. See Poly (DL-lactic acid) Poly (lactic acid) Placcel. See e-Caprolactone monomer Placenta extract, human. See Human placental protein... 

C6H10O2 Acetyl butyryl Allyl glycidyl ether Allyl propionate e-Caprolactone monomer Cyclopentane carboxylic acid Ethyl crotonate Ethyl methacrylate 5-Hexalactone y-Hexalactone... 

Messersmith and Giannelis [20] also reported the preparation of nanocomposites by reacting protonated 12-aminolauric acid-exchanged montmorillonite with e-caprolactone monomer. The monomer ring was initially intercalated in the gaps... 

NMR Spectroscopy. H and C NMR spectra were recorded on a Bruker ARX-360 spectrometer at 360 and 90 MHz and a Bruker DPX-2S0 spectrometer at 250 and 62.9 MHz, respectively. H NMR chemical shifts (ppm) are reported downfield from 0.00 ppm using tetramethylsilane (TMS) as an internal standard. The concentrations used were -4% w/v in chloroform-d (CDCl,). C NMR spectral chemical shifts in (ppm) are referenced relative to the internal standard chloroform-d at 77.00 ppm. 4-Methyl-e-caprolactone monomer conversions were determined from the relative peak areas of H NMR signals corresponding to methyl (-CH3) protons in the polymer and the monomer at 0.93 and 0.99 ppm, respectively. 4-Ethyl-e-caprolactone monomer conversions were determined from the relative peak areas of H NMR signals corresponding to methylene (-... 

Lactide is also copolymerized with e-caprolactone monomer to produce biomaterials for the manufacture of surgical implants and drug carriers. The copolymeiization of lactide—caprolactone follows a similar reaction path as lactide—glycolide. The preference is for a random copolymer comprising of 55—70 mol% of lactide and 30—45 mol% of caprolactone for application as a pharmaceutical carrier (Bezwada, 1995). 

Figure 12. Mass spectrum of e-caprolactone monomer obtained by TG-MS...

In recent years homoleptic lanthanide(III) tris(amidinates) and guanidinates have been demonstrated to exhibit extremely high activity for the ring-opening polymerization of polar monomers such as e-caprolactone and trimethylene... 

The living nature of PCL obtained in the presence of Zn(OAl-(OPri)2)2 has been used to prepare both di- and triblock copolymers of e-caprolactone and lactic acid (42,43). Treatment of the initial living PCL with dilactide afforded a PCL-PLA diblock with M /Mn = 1.12, with each block length determined by the proportions of the reactants, i.e., the ratio of [monomer]/[Zn]. While the living diblock copolymer continued to initiate dilactide polymerization, it failed to initiate e-caprolactone polymerization. To obtain a PCL-PLA-PCL triblock, it was necessary to treat the living PCL-PLA-OAIR2 intermediate with ethylene oxide, then activate the hydroxy-terminated PCL-PLA-(OCH2CH2)nOH with a modified Teyssie catalyst (Fig. 5). 

Ring-opening polymerization of 2-methylene-l,3-dioxepane (Fig. 6) represents the single example of a free radical polymerization route to PCL (51). Initiation with AIBN at SO C afforded PCL with a of 42,000 in 59% yield. While this monomer is not commercially available, the advantage of this method is that it may be used to obtain otherwise inaccessible copolymers. As an example, copolymerization with vinyl monomers has afforded copolymers of e-caprolactone with styrene, 4-vinylanisole, methyl methacrylate, and vinyl acetate. 

The relative rates of polymerization of a series of substituted e-caprolactones initiated by (246) demonstrate that methyl groups, particularly adjacent to the acyl oxygen, retard polymerization.757 In addition, the rate of polymerization of the parent unsubstituted CL at 25 °C was found to be 4 x 102 times greater than L-LA at 70 °C. The slower propagation of LA is usually attributed to coordination of the nearest inserted carbonyl of the polymer chain to the A1 center, leading to formation of a stable 5-membered chelate, which hinders monomer uptake.758... 

So far, many studies have focused on the development and application of aliphatic polyesters such as PLA [1-3], PGA [41,42], and PCL [43,44], Figure 2 shows the structures of their monomers lactides (LAs), glycolide (GA), e-caprolactone (CL), and some typical comonomers. 

It should be mentioned that when a hexa(hydroxyl) initiator is used for the lipase catalyzed polymerization of s-CL, only one hydroxy function is active [100]. This leaves five remaining OH groups for polymerization of new or another monomers. Comb poly(e-CL)s have also been prepared [101, 102] starting from a copolymer of e-CL and 5-ethylene ketal-e-caprolactone as shown below ... 

Pitt et al. [65], and more recently, Albertsson et al. [73], have prepared chemically cross-linked aliphatic polyesters by ROP of the corresponding cyclic ester monomers in the presence of Y,y -bis(e-caprolactone)-type comonomers (Scheme 17). The cross-linked films displayed different swelling behaviors, degradability, and elastomeric properties depending on the nature of the lactone and composition of the comonomers feed. 

Besides the investigation of stereoisomers, the degradation of copolymers with E-caprolactone [24, 28, 29], 5-valerolactone [24, 28, 29], y-butyrolacton [30] and D,L-lactide [31] were also studied. The trends are found to be independent of the co-monomer. Co-monomer units within the polymer lead to an increase of degradation rate up to ten times that of natural PHB. The reason for this finding is the change of crystallinity within in the synthetic material, which could by proved by various DSC measurements of different copolymers and compositions. 

Basko M, Kubisa P (2006) Cationic copolymerization of E-caprolactone and L,L-lactide by an activated monomer mechanism. J Polym Sci A Polym Chem 44 7071-7081... 

Liu M, Vladimirov N, Frechet JMJ (1999) A new approach to hyperbranched polymers by ring-opening polymerization of an AB Monomer 4-(2-hydroxyethyl)-e-caprolactone. Macromolecules 32 6881-6884... 

The first enzymatic polymerizations of substituted lactones were performed by Kobayashi and coworkers using Pseudomonas fluorescens lipase or CALB as the biocatalyst [90-92]. A clear enantiopreference was observed for different lactone monomers, resulting in the formation of optically active polymers. More recently, a systematic study was performed by Al-Azemi et al. [93] and Peelers et al. [83] on the ROP of 4-alkyl-substituted CLs using Novozym 435. Peelers et al. studied the selectivity and the rates as a function of the substituent size with the aim of elucidating the mechanism and the rate-determining step in these polymerizations. Enantio-enriched polymers were obtained, but the selectivity decreased drastically with the increase in substituent size [83]. Remarkably for 4-propyl-e-caprolactone, the selectivity was for the (R)-enantiomer in a polymerization, whereas it was S)-selective in the hydrolysis reaction. Comparison of the selectivity in the hydrolysis reaction (Fig. 10b) with that of the polymerization reaction (Scheme 8a) revealed that the more bulky the alkyl substituent, the more important the deacylation step becomes as the rate-determining step. 

Here we discuss dispersion polymerizations that are not related to vinyl monomers and radical polymerization. The first one is the ring-opening polymerization of e-caprolactone in dioxane-heptane (30). A graft copolymer, poly(dodecyl acrylate)-g-poly(e-caprolactone), is used as a stabilizer. The polymerization proceeds via anionic or pseudoanionic mechanism initiated by diethylaluminum ethoxide or other catalysts. The size of poly(caprolactone) particles depends on the composition of stabilizer, ranging from 0.5 to 5 i,m. Lactide was also polymerized in a similar way. Poly(caprolactone) and poly(lactide) particles with a narrow size distribution are expected to be applied as degradable carriers of drugs and bioactive compounds. 

The ease of synthesis of oxepan-2-one (e-caprolactone 78) on a commercial scale has led to its use as a monomer in the production of poly-e-caprolactone. The latter polymer has been widely used as an additive and plasticizer. Over the last decade a large number... 

More recently Teyssie determined the rate constants in the polymerization of e-caprolactone (eCL) initiated with aluminium alkoxides, believing that the covalent species are the only ones responsible for propagation [4]. For the same monomer Yamashita estimated tentatively rate coefficients of propagation using an anionic initiator [ ]. Lenz in his studies of substituted g-propiolactones (gPL) observed peculiar influence of structure on reactivity that can have its origin in the multiplicity of ionic structures involved [fi]. 

---