Synthesis of block and grafted copolymers containing spacer‐linked chromophore based on cellulose and polyethylene glycol

Abstract

A series of block copolymers from hydroxylterminated cellulose triacetate (HCTA) and cellulose triacetate (CTA) with polyethylene glycol (PEG) were prepared. To activate terminal acid groups in the polyethylene glycols, acid groups were first converted to the acetyl groups with chlorination reaction. In the second series, the cellulose triacetate, having fully substituted acetate groups, was hydrolyzed by the acid catalyst method by using acetic acid and small percentages of water. Then cellulose derivatives containing 4-(4-nitrophenylazo)-1-naphthol (Magneson II) as a chromophore and long hydrocarbon side chains were prepared. The compound 4Ј-bromobutoxy-4-(4-nitrophenylazo)naphthalene was first synthesized from 4-(4-nitrophenylazo)-1-naphthol and 1,4-dibromobutane. The alkylated chromophore reacted with prepared cellulosic and oligocellulosic copolymers in the solution of dimethyl sulfoxide to produce cellulose ethers having the desired chromophore. Polymers containing a mixture of alkyl side chains were also prepared by the addition of 1-bromododecane to the reaction mixture. The above method was used for the preparation of (dodecyl) [4Ј-butoxy-4-(4-nitrophenylazo)naphthalene] (CTA-co-PEG2000) and (dodecyl) [4Ј-butoxy-4-(4-nitrophenylazo)naphthalene] (HCTA-co-PEG2000). The structure of products was determined by FTIR, 1 H-NMR spectroscopy, GPC, and the intrinsic viscosity measurement.

Synthesis, morphology, and melting behavior of poly(ether ether ketone) of different molecular weights

“…5). From the function d = λ X‐ray /2sin θ,43 the interplanar crystal spacing was obtained as 0.472, 0.430, 0.388, and 0.310 nm, respectively. It should be noted that the 2θ of the peaks of the WAXD reflection were not influenced by the molecular weight indicating that the crystal structure type remained the same despite the changes of the molecular weight.…”

“…Intrinsic viscosities of PEEK products were obtained by measurements with Ubisch viscometer of 0.9–1.0 mm and a series of operations 8, 42, 43. Intrinsic viscosity in this article was measured at 25°C on a solution of the polymer in concentrated sulfuric acid of density 1.84 g/cm 3 , said solution containing 0.1 g of polymer per 100 cm 3 of solution.…”

Nanoparticles Based on Modified Polysaccharides

“…Modified celullose have received wide applications for the stabilization of disperse systems, in particular suspensions and emulsions (Namazi and Rad, 2004). The most important types of associating polymers are water-soluble amphiphilic polymers, notably block or graft copolymers, with hydrophobic blocks or grafts.…”

Preparation of the new derivatives of cellulose and oligomeric species of cellulose containing magneson II chromophore

“…A modified method reported in literature was employed. 34 CTA (250 mg, 0.003 mmol) was dissolved in a solution of DMSO 30 mL and water 0.5 mL under nitrogen. After stirring at room temperature for 1 h, the powder NaOH was added (12.5M excess relative to the three substitution sites per glucose unit).…”