Aldehyde poly

The linear dependence of the optical activity on temperature has been observed by Pino and co-workers (116) and by Goodman and co-workers the latter demonstrated that in the case of poly-(R)-3.7-dimethyl-l-octene (43) like in the case of poly-aldehydes (7), the absolute value of the ratio —Jy increases by decreasing the wavelength... 

Di-poly Aldehydes (and ketones) FFAP QF-I, Porapak-Q, Porapak-QS Apiezon L, M carbowax 400, 750, 1000, 1500, 1540 di-n-butyl phthalate diethylene glycol succinate ethylene glycol succinate Hallcomid M18 squalene tricresyl phosphate 1,2,3-tris (2-cyanoethoxy) propane Ucon series... 

We started our investigation in 1957 and worked out initially reliable methods for preparing amorphous atactic polyacetaldehyde (16). Soon thereafter we discovered crystalline isotactic poly aldehydes (49, 51). Detailed studies of polymerization conditions, polymer structures, and stabilization of the polymers followed. 

Subsequently, and independently from us, Furukawa (17, 18, 19, 21) and Natta (34, 36) also succeeded in preparing amorphous and crystalline poly-aldehydes. 

Table IV gives an example of our own work on the polymerization of a number of higher aldehydes. Potassium triphenylmethoxide—a soluble initiator—polymerized a number of higher aldehydes to crystalline isotactic poly aldehydes. Table V lists a number of alkali alkoxides and other related compounds used as initiators for the n-butyraldehyde polymerization. Neither the type of the alkoxide nor the cation is of any great importance for the polymerization rate, the polymer yield, and stereoregularity of the resulting polyaldehyde as long as the initiator is adequately soluble in the reaction mixture.

Most isotactic polyaldehydes are insoluble at room temperatures but are soluble at elevated temperatures in some solvents. We have studied the gel point, which is a measure of polymer solubility. A number of poly aldehydes were investigated in tetrahydronaphthalene polyformaldehyde has the highest gel point observed—namely, about 200° C. For the series of unbranched polyaldehydes the gel point decreases with the increasing length of the aliphatic side chain (Table VI) and parallels the melting points of the polymer. 

Poly-cyanides and iso-cyanides Poly-hydroxy compounds or poly-acid alcohols Poly-aldehydes... 

K.Y. Lee, K.H. Bouhadir, D.J. Mooney, Degradation behavior of covalently cross-linked poly (aldehyde guluronate) hydrogels. Macromolecules 33 (1) (2000) 97-101. 

As illustrated by the example of dicyclopentadiene, non-conjugated double bonds can be hydroformylated like isolated olefins, but rapid conjugation prior to the hydroformylation may prevent the formation of the expected poly-aldehydes. In the hydroformylation of 1,5-cyclooctadiene with unmodified Co or Rh catalysts, the main product was formyl cyclooctane [88]. In contrast, cycloheptatriene was formylated twice. The amount of triformylcycloheptanes did not exceed 10%. 

Acrolein and acrylic acid were copolymerized in aqueous H2O2 solution at 60 to 90 °C to form poly(aldehyde carbon acids). The Cannizzaro reaction took place if an aqueous... 

Bouhadir, K.H., Hausman, D.S., Mooney, D.J., 1999. Synthesis of cross-linked poly(aldehyde guluronate) hydrogels. Polymer 40, 3575-3584. 

Lee KY, Alsberg E and Mooney DJ. 2001. Degradable and injectable poly(aldehyde guluronate) hydrogels for bone tissue engineering. / Biomed Mater Res 56(2) 228-233. 

From a fundamental physico-chemical point of view, a need exists to compare polyphosphazenes directly with closely related structural analogues in other areas of polymer chemistry. For example, valuable comparisons could be made between polyphosphazenes on the one hand and poly(organosiloxanes) or poly(aldehydes) on the other. Unfortunately, such direct comparisons are not yet possible. The structural analogue of poly(dimethylsiloxane), i.e. [NP(CH3)2]n> not yet been synthesized. Polysiloxanes with alkoxy, aryloxy, or amino residues as the sole side groups are not available. No polyphosphazenes have yet been prepared with two hydrogen atoms on each phosphorus to provide a comparison with poly(oxymethylene). Thus, many synthetic challenges still remain. 

Poly(aldehydes) general Extraction Boiling acetone, diisopropyl Amorphous -t- crystalline 2368... 

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