Sn octoate

Schwach, G., Coudane, J., Engel, R., Vert, M., 1996. Zn lactate as initiator of OL-lactide ring opeiung polymerization and comparison with Sn octoate. Polymer Bulletin 37, 771-776. 

We see that the two amine catalysts, DABCO and N-ethylmorpholine, are added in the amount of about 1 % based on the polyol component, while the amoimt of Sn-octoate is 0.15%. While DABCO is a balanced catalyst, which promotes both gelation and foaming, N-ethylmorpholine favors open cell formation. The surfactant has multiple role, to lower surface tension and facilitate division of cells, and since it is a separate phase, to act as a nucleant. Increasing the amount of surfactant gives finer cells with thinner walls until the limit is reached above which it causes foam collapse. Density of flexible foams is usually between 30 and 80kg/m. Density of the polyurethane itself is about llOOkg/m. ... 

The kinetics of IPN formation was studied for the system PU/cross-linked PMMA [260]. PU was formed from POPG MM 2000 and from aromatic triisocyanate adducts in the presence of catalyst (Sn octoate). The PMMA network was synthesized by radical copolymerization of MMA and trimethy-lolpropane trimethacrylate using AIBN as initiator. First, the PU network was formed at room temperature and then at 223 K the second network was polymerized. The effect of all components of one of the networks was studied on the gelation of the other. The effect of the catalyst Sn octoate on the PMMA gel formation consisted in a decrease in the rate of gelation from 180 to 30 min. At the same time, the PMMA network components do not influence the PU network formation. The first effect was explained by the increase of the viscosity of the reaction medium, leading to an increased rate of PMMA formation in the presence PU components due to a smaller termination constant according to the equation [261] ... 

It was established [262] that the catalyst Sn octoate does not exert any effect on the initiator decomposition rate, but enhances the polymerization rate of monomer and comonomer due to polarization of double bonds, making addition of radicals easier as a result, the rate of PMMA formation increases. The possibility of chemical bond formation between PU and the PMMA network was also discussed. One should never forget such a possibility because of the possible chain transfer to another polymer. Two components of the PU network—POPG and triisocyanate adduct—both containing mobile hydrogen atoms, are present in the reaction medium. Because this atom may be shipped off by a radical, the possible reaction may be presented as consisting of two stages ... 

Homogeneous catalysis by lin compounds is also of great indusirial importance. The use of SnCU as a Friedel-Crafts catalyst for homogeneous acylation, alkylation and cyclizaiion reactions has been known for many decades. The most commonly used industrial homogeneous tin catalysis, however, are the Sn(ll) salts of organic acids (e.g. acetate, oxalate, oleale, stearate and ocToate) for the curing of silicone elasloniers and, more importantly, for the production of polyurethane foams. World consumption of tin catalysts for the.se Iasi applications alone is over 1000 tonnes pa. 

Two different mechanisms have been proposed for the ROP of (di)lactones depending on the nature of the organometalhc derivatives. Metal halides, oxides, and carboxylates would act as Lewis acid catalysts in an ROP actually initiated with a hydroxyl-containing compound, such as water, alcohol, or co-hydroxy acid the later would result more hkely from the in-situ hydrolysis of the (di)lac-tone [11]. Polymerization is assumed to proceed through an insertion mechanism, the details of which depends on the metal compound (Scheme la). The most frequently encountered Lewis acid catalyst is undoubtedly the stannous 2-ethylhexanoate, currently referred to as stannous octoate (Sn(Oct)2). On the other hand, when metal alkoxides containing free p-, d-, or f- orbitals of a favo-... 

For a better understanding of the probe behavior in PDMS networks it was necessary to investigate the fluorescence behavior of a probe covalently bonded to a soluble polydimethylsiloxane chain. Therefore, a dialkoxysilane containing 4-piperidinobenzoic acid ester was allowed to react with a hydroxyl-terminated polydimethylsiloxane giving a soluble polymer with a covalently bonded probe at the main chain. This reaction occurs in the presence of Sn(II) octoate. The reaction scheme is drawn in Fig. 4. It was shown by GPC (UV detection) and NMR spectroscopy that the probe reacted with the hydroxyl groups of the polydimethylsiloxane chains. 

Stannous octoate (Sfannoos 2-ethylhexanoate), Sn[OOCCH(C2Hs)CH2CH2CH2-CH3]2. MoI. wt. 405.11. Suppliers Albright and Wilson Metal and Thermit Corp. (Catalyst T9) ROC/RTC. 

Positive ion MALDI-TOF mass spectrometry of macromolecules prepared by ring-opening polymerization of e-caprolactone with tin(II) octoate [Sn(Oct)2], in the presence of R OH (water or alcohol) as co-initiator, revealed that there is a sizeable population of macromolecules having Sn atoms in the chains, either linear and/or cyclic ones ... 

Kricheldorf, H.R., and Kreiser-Saunders, I., Polylactones 31. Sn (lI)octoate-initiated Polymerization of L-Lactide. A Mechanistic Study. 1995, Boettcher, C. Polymer, 36 1253... 

SIUIO. SeeSorbitanoleate SMS. See Sorbilan stearate Sn-(ll)-ethylhexanoate. See Stannous octoate Soap clay. See Bentonite Soda lye. See Sodium hydroxide Soda mint See Sodium bicarbonate Soda niter Soda nitre. See Sodium nitrate Sodium acid carbonate. See Sodium bicarbonate Sodium acid phosphate. See Sodium phosphate... 

Synonyms Sn-(ll)-ethylhexanoate Stannous 2-ethylhexanoate Stannous-2-ethylhexoate Tin octoate Tin-(ll)-octoate Empiricail CjsFIsoQiSn Formula Sn(C8H,sQ2)2... 

Ethylhexanediol 2-Ethyl-1,3-hexanediol 2-Ethylhexane-1,3-diol 2-Ethylhexanediol-1,3. See Ethyl hexanediol Ethyl hexanoate. See Ethyl caproate Sn-(ll)-ethylhexanoate. See Stannous octoate 2-Ethylhexanoic acid a-Ethylhexanoic acid. 

Hydroxyl-substituted bipyridine Ru-centered complexes have also been used to promote the ROP of c-caprolactone and lactide in the presence of starmous octoate, Sn(Oct)2. ... 

However, ROP promoted by organometallics like tin(II) octoate (Sn(Oct)2) represents the most privileged synthetic pathway as it overcomes the major drawbacks of the polycondensation process in terms of release of by-products and use of high temperatures, and can be carried out in solution as well as in bulk, that is in the absence of solvents. Due to the presence of two chiral centres, LA exists as optically active D,D-lactide (u-LA) or L,L-lactide (l-LA)... 

Coordination-insertion polymerization has been extensively used for preparing polymers such as polyesters and polyphosphoesters with well-defined molecular profiles. The most widely used polyesters such as polylactic acid (PLA) and poly (lactic-co-glycohc acid) (PLGA) are produced on industrial scale by following the coordination-insertion polymerization method catalyzed by tin(II)bis (2-ethyUiexanoate) (Stannous octoate, Sn(Oct)2). Other metal alkoxides containing free p-, d-, or/-orbitals such as Mg-, Ti-, Zr-, Fe-, A1-, Y-, Sm-, and Zn-alkoxides are also widely used as the catalyst for this type of polymerization [61]. 

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