Poly-n-butyraldehyde

Other polyaldehydes, such as poly-n-butyraldehyde, can also be obtained as amorphous polymer with cationic initiators, although an increase in the bulkiness of the side chain facilitates the formation of stereoregular polymers or at least increases the regularity of the polymer. 

Internal friction measurements have also been carried out on amorphous poly acetaldehyde and showed a main amorphous transition at -18° C. Poly-n-butyraldehyde had a transition at room temperature (Figure 1). 

Table VII. Solvents for Acetate End-Capped Poly-n -Butyraldehyde...

Figure 5. Solution viscosity vs. end group relationship for poly-n-butyraldehyde. The inherent viscosity was measured in 0.5% tetrahydronaphthalene at 140° C.

Cold pressed wafers (0.2mm.) of completely acetate, end-capped, and refined poly-n-butyraldehyde samples were used for the infrared determinations... 

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.

The selective hydrogenation of an olefinic bond in crotonaldehyde gives n-butyraldehyde in presence of a suitable catalyst n-butyraldehyde reacts with poly (vinyl alcohol) to form poly (vinyl butyral) which is used as an interlayer for safety glass as well as for coating fabrics and for injection-moulding compositions. Butyraldehyde also finds use in making oil-soluble and alcohol-soluble resins. Butyraldehyde is a raw material for the manufacture of butyric acid and butyric anhydride... 

Poly(vinyl butyral) prepared by reacting PVA with n-butyraldehyde finds wide application as the interlayer in safety glass and as an adhesive for hydrophilic surfaces (128). Another example is the reaction of PVA with formaldehyde to form poly(vinyl formal), used in the production of synthetic fibers and sponges (129). 

Today the installed hydroformylation capacity worldwide is more than 7.5 Mio tons per year (Baerns et al., 2006). The most important feedstock is propene, with the products n-butyraldehyde and iso-butyraldehyde (Scheme 6.14.3). The most important single product from propene hydroformylation is 2-ethyl-l-hexanol (>50% of the n-butyraldehyde production), the aldol condensation product obtained from n-butanal, which is an important plasticizer alcohol. After esterification with phthalic anhydride, dioctyl phthalates plasticizers are obtained that are used mainly in poly(vinyl chloride) plastics. 

Other aldehydes used for the synthesis of phenolic polycondensates include butyraldehyde, furfural or chloral. Efficient AO, e.g. polycondensate 129, were prepared with sulfur containing aldehydes [161]. Linear polycondensates of phenols and aldehydes were tested as AO in mineral oils, PE, PP, poly (ethylene-co-propylene), PS, PA and/or diene based rubbers [159, 162]. Cyclic phenolic condensates, calixarenes (130) posses interesting properties. Calixarenes were synthesized from 4-acyl-, 4-methyl-, 4-tm-butyl- or 4-phenylphenol in alkaline catalysed processes. Cycles containing 4 to 7 phenolic units were formed and tested as AO in PE or PP [163,164], Nickel(II) salt of 130 (R = lerf-butyl, n = 1)... 

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