TMO copolymerization

TMO Copolymerization With Saturated Epoxides. Copolymerizing TMO with ethylene oxide (EO) in an 80 20 weight ratio with the chelate catalyst gave a water-soluble product (90% of the total) which contained only 8% TMO (Run 2, Table II). On the basis of an ideal copolymerization, the EO is estimated to enter the copolymer in this fraction approximately 70 times more readily than does the TMO. This result confirms that alkylene oxides polymerize much more readily than oxetanes with the chelate catalyst. A small amount (10% of the Total) of a water-insoluble copolymer containing 44% TMO was obtained. This result indicates that the chelate catalyst contains some sites which give more favorable copolymerization. One possible explanation is that the unfavorable copolymerization of TMO at the major sites is due to steric hindrance which reduces the ability of TMO to coordinate at this site. 

The first coordination polymerization of an oxetane, trimethylene oxide (TMO), occurs readily, much like propylene oxide (PO), with the Et3Al-H20-acetyl acetone catalyst at 65 C., to give high molecular weight polymer (n jjj up to 12). TMO copolymerizes with epoxides with this coordination catalyst. For example, TMO copolymerized well with allyl glycidyl ether (AGE) which was about seven times more reactive than TMO, in contrast to the PO-AGE copolymerization in which both monomers are of equal reactivity. 

A 96-4 TMO-AGE copolymer prepared under conditions to make it reasonably uniform gave an interesting sulfur-curable elastomer. Preliminary vulcanizate data on this elastomer show good tensile and tear properties, a low Tg (-75 C.), high resilience, and good heat resistance. Further development of this family of interesting elastomers requires a lower cost route to TMO. Copolymerizations of TMO with other epoxides and oxetanes as well as the polymerization of other oxetanes are also described. 

The trend was studied and verified, for instance, for reactions catalysed by transition metal, organo- and enzyme catalysts entrapped in ORMOSIL prepared by copolymerization of tetramethoxysilane (TMOS) and the modifying co-precursor methyltrimethoxysilane (MTMS). It has been correlated with the encapsulation itself but also with the structure of the sol-gel matrix, namely the hydrophobicity-lipophilicity balance (HLB) and the textural properties of the materials.9... 

The copolymerization of TMO and epichlorohydrin (ECH) with the chelate catalyst and a 50 50 weight ratio charge is more favorable (Run 3, Table II) again, two fractions, both rubbery in nature, were obtained which differed in solubility and composition. Thus, the chelate catalyst again appears to contain at least two different copolymerization sites. It is significant that these two monomers, which probably have similar steric requirements, do copolymerize better, thus adding credence to the earlier proposal that steric restrictions at certain sites affect... 

A copolymer of TMO with butadiene monoxide (BMO) was also made by using the same procedure as in the large sample method for TOO-AGE (Run 6, Table II). Since ffllO gives ideal copolymerization with PO, as does AGE, with the chelate catalyst, it was assumed that the system which worked with TOO-AGE would work with TMO-BMO. 

TMO was also copolymerized with an unsaturated oxetane, 3,3-bis(allyloxymethyl)oxetane (BAIU) (Run 3, Table III). This work was done with the Et3Al-0.5H2O catalyst. This copolymerization appears to be a nearly perfect one. 

The copolymerization of PO with BCMO using the chelate catalyst (Run 8, Table III) at 30°C. indicates that the PO enters the copolymers about thirtyfold more readily than does BCMO, based on ideal copolymerization. This result is similar to our findings on the copolymerization of TMO with ethylene oxide. 

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