Cotton substrates, graft

This is a report of a study to use depolymerization or degradation and polymerization reactions within the rf reactor to advantage in the formation of new polymers and to Investigate the relative contributions of rf produced particles (electrons and ions) and of rf produced uv light in the Initiation of graft polymerizations on cotton substrates. 

A vapor phase grafting process based on the ozonization of polymer films and fabrics followed by a treatment with vapors, such as acrylonitrile, dichloroethylene, and vinyl acetate, has been patented by Polyplastic (66). Also cotton fabrics can be used as substrates. 

The selective oxidation of cellulose to dialdehyde by sodium periodate is well known. It has been postulated by Criegee (74) and by Waters (73) that this reaction proceeds by a free radical mechanism. Toda (76) and Morimoto, Okada, Okada, and Nakagawa (77) have concluded that sodium periodate oxidation should initiate graft polymerization. They succeeded in grafting methyl methacrylate and acrylonitrile onto cellulose substrates, such as rayon and paper. A similar procedure is recommended in a patent of Chemische Werke Huels (78) to graft vinyl monomers onto cotton, polyethylene oxide, copolymers of vinyl chloride-vinyl acetate, and others. 

It was reported that the oxidative thermal degradation of the grafted fiber depended on the amount of grafted polymer and on the structure of the cellulose substrate (cotton cellulose, rayon, etc.). 

As it is well established, polymer brushes on flat substrates can be treated to a first approximation as a linear string of blobs of equal size [2]. On the other hand, in the case of a brush grafted on a curved surface (convex or concave), the theoretical analysis of the system is somewhat more complicated than the case of flat surfaces, and that is because the surface curvature leads to the modification of the available space for each grafted chain. Following the classic theoretical analysis of Daoud and Cotton for star polymers [3], brushes on curved surfaces can be envisioned as an array of concentric shells of blobs that have variable size as we move away from the... 

Some of the historical background to this variety of approaches and an account of the most recent improvements have been reviewed in other components of this symposium publication. Here we characterize the biological performance of only that method based upon the procedure described by Sun and Xu in a series of reports and US Patent 5,822,357 In it, grafted heterocyclic ring compounds, hydantoins, serve as chlorine stabilizers covalently linked to the cellulose substrate, with the latter represented by cotton, wood pulp or even on wood surfaces themselves. 

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