S Propiolactone

Materials. PCL and polypropiolactone (PPL) were prepared by ring opening polymerization of e -caprolactone ( ) and S -propiolactone respectively in benzene in a nitrogen atmosphere at 60 C with a di-... 

The reaction has been extended to a synthesis of terpenes from / -methyl-/S-propiolactone, available by hydrogenation of ketene dimer.9 Example ... 

Photopolymerization of acrylamide by the uranyl ion is said to be induced by electron transfer or energy transfer of the excited uranyl ion with the monomer (37, 38). Uranyl nitrate can photosensitize the polymerization of /S-propiolactone (39) which is polymerized by cationic or anionic mechanism but not by radical. The initiation mechanism is probably electron transfer from /S-propiolactone to the uranyl ion, producing a cation radical which propagates as a cation. Complex formation of uranyl nitrate with the monomer was confirmed by electronic spectroscopy. Polymerization of /J-propiolactone is also photosensitized by sodium chloroaurate (30). Similar to photosensitization by uranyl nitrate, an election transfer process leading to cationic propagation has been suggested. 

The acidity function has been used in analyzing the kinetic data on acid-catalyzed reactions in concentrated solutions. Longhand Purchase found that the rate of hydrolysis of /S-propiolactone in concentrated aqueous solutions of H2SO4 and HCIO4 is first-order in lactone and proportional to ho. The over-all reaction is... 

The conpling constant of the AA BB portion of bisphenol A-neopentyl glycoltereph-thalate copolyesters (20) was determined in the presence of Pr(fod)3". The compositional tetrads of a 3,3 -dimethylbisphenol A-phenolphthalein copolyterephthalate (21) were resolved in the presence of En(fod)3 . The meso and racemic dyads of a poly(/l-snbstitnted- S-propiolactone) were distinguishable in the NMR in the presence of Eu(dpm)3". The H and NMR spectra of ethylene-vinyl acetate copolymers were assigned on the basis of two-dimensional NMR methods and lanthanide-induced shift data in the presence of Eu(fod)3". ... 

Long and his co-workers (Long, Dunkle, and McDevit, 75) have used the acidity function to decide whether or not a water molecule is present in the activated complex in the acid-catalyzed hydrolysis of 7-butyro-lactone. They found no correlation with Ho and therefore conclude that the water molecule is present in the activated complex. This is in contrast to their findings for the hydrolysis of /S-propiolactone. Paul (76) has studied the decomposition of trioxane in mixtures of perchloric acid and sodium perchlorate at constant perchlorate concentration (6 M) and found good correlation with the acidity function as determined by Harbottle (77). 

Diketene also is widely employed as a natural and synthetic fiber cross-linking agent, wood preservative and paper-sizing agent. Both it and /S-propiolactone have wide application as chemical intermediates. The synthetic applications of diketene for the synthesis of aromatic, heterocyclic and aliphatic compounds is exceptionally extensive (74ACR265). 

In a new method of carboxyethylatiotf a ketone (3) is converted into the morpholine enamine (4), and this is heated with /S-propiolactone to effect condensation... 

Table III. Rate Constants for the Polymerization of C -Ethyl-( -n-butyl-S-propiolactone Initiated by TEAB in DMSO...

Even carboxylate ions can serve as active centres of )S-propiolactone polymerization [316]. Cationic polymerization is characterized by the formation of an oxonium transition salt generated by the reaction of an active centre with an exo- or endocyclic oxygen atom. The reaction mode depends on the kind of initiator and monomer [317]... 

Draw a short section of the polymer obtained from anionic polymerization of )S-propiolactone. 

Catalytic systems for ring-opening of lactones have also been studied with mechanistic interpretation of the reaction in the case of soluble aluminium-zinc and cobalt-aluminium-oxoalkoxides. Insertion into the aluminium alkoxide bonds by monomer is su ested. These systems have been employed to synthesize lactone block copolymersvia living ring-opening polymerization in homogeneous oi anic phase. c-Caprolactone/)S-propiolactone block copolymers were obtained in a quantitative manner only in the presence of dissociated catalyst. 

Previous investigations in this laboratory (1 ) and elsewhere (2) have shown that polyesters prepared from chiral o,o-disubstTtuted-s-propiolactones by the following reactions ... 

One purpose of the present investigation was to obtain some additional information on structure-crystallinity relationships in this family of polymers by the preparation of stereoregular isotactic polyesters from a single asymmetric isomer of the chiral monomer that is, from an optically-active a,a-disubstituted-s-propiolactone. Because the polymerization reaction mechanism operates through scission of the alkyl-oxygen bond and does not involve bond reorganizations at the asymmetric center, it was fully expected that polymerization of the optically-active monomer... 

Surface active agents /8-Methylene- S-propiolactone United States 2,585,537 1952 DuPont... 

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