ABSTRACT:The deterioration behavior of cellulose acetate (CA) films (degree of substitution ϭ 2.5) was examined in hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions of various concentrations to determine acid and base catalytic effects in heterogeneous systems at room temperature. With concentrations of 0.5N HCl and 0.01N NaOH and higher, the physical properties of the films changed. The films, recovered after 1-10 days of immersion, were slightly opaque and rubbery from swelling in the solutions before drying. They became brittle and shrank when they dried. For HCl immersion, the weight change of a film depended on the HCl concentration and the immersion time. With 6.0N HCl, the film shape was broken, and a fine powder was deposited in the solution with a recovery of 53.8 wt %. The infrared spectrum of this deposit indicated that it was completely deacetylated cellulose. For NaOH immersion, although the weight change depended on the NaOH concentration, the weight loss reached 40 -50% within the first 24 h, and it was constant with respect to the immersion time and base concentration in 0.5N NaOH or NaOH of a higher concentration. The infrared and gel permeation chromatography analyses showed that this deterioration mainly depended on the deacetylation of CA.
The complex [ MoH,(dppe),] (1 ) (dppe = Ph,PCH,CH,PPh,) reacted with ally1 carboxylates RCO,CH,CH=CH, (R = H, Me, Et, Pr", But, CH,=CMe, or Ph) in benzene upon irradiation with a high-pressure mercury lamp to give [MoH(O,CR) (dppe),] (2), together with propene and H, .Reaction pathways comprising the oxidative addition of the ally1 carboxylates involving allyloxygen bond cleavage are proposed on the basis of the results obtained with substituted allylic esters. The complexes (2) were characterized spectroscopically as having pentagonal-bipyramidal structures in solution. The similar reaction of complex (1 ) with ally1 formate led t o selective cleavage of the formic C-H bond to give ultimately the known cis-[Mo(CO),(dppe),] via (2; R = H).
For binary blend films of cellulose acetate (CA) and various polymers, the elution behavior of the polymers from the CA films in different environments (i.e., soil, water) was examined. For the CA film containing poly-(ethylene glycol) (PEG), the PEG eluted to the periphery of the film completely. On the other hand, polyvinylpyrrolidone blended with CA remained in the CA film. A CA film containing acrylic acid was prepared, and this film was heated. The elution of acrylic acid was inhibited by its polymerization. These results suggested that the internal polymers were capable of remaining in the CA film by polymer entanglement. Second, we examined the deacetylation and biodegradation behavior of CA films containing polymers with a phosphoric acid moiety in the side chain, such as poly(2-hydroxyethyl methacrylate phosphoric acid ester)[poly(HEMA-P)]. Poly(HEMA-P) had the ability to deacetylate the CA, and the biodegradation rate of the CA films containing poly(HEMA-P) increased in comparison with that of the nonadditive CA films. The elution of internal 2-hydroxyethyl methacrylate phosphoric acid ester was inhibited by the copolymerization with 2-hydroxyethyl methacrylate or crosslinking. In the case of both 2-hydroxyethyl methacrylate phenyl phosphoric acid ester and 10-methacryloyloxydecyl dihydrogen phosphate, the acetonesoluble polymers were obtained by radical polymerization in a mixture of acetone and water.
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