Acrylonitrile grafting cellulose

This reaction is utilized by Burrows et al. [70] to photoinitiate grafting of acrylamide, acrylic acid, methacrylamide, and acrylonitrile on cellulose triacetate in acidic aqueous solution. 

The pyrophosphate complex of Mn(II) ion was found to initiate grafting of acrylonitrile onto cellulose and its derivatives [36,37],... 

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. 

Fig. 4. UV grafting of acrylonitrile to cellulose film in dimethyl formamide solution with 10% water and 0.01 M 2,7 anthraquinone sodium disulfonate (112). — in air, C —in vacuo...

Hassanpour, S. Radiation grafting of styrene and acrylonitrile to cellulose and polyethylene. Radiat. Phys. Chem. 55, 41-45 (1999)... 

Kalf et al. studied the effect of grafting cellulose acetate and methylmethacrylate as compatibilizers on acrylonitrile butadiene rubber (NBR) and styrene-butadiene rubber (SBR) blends. Morphology studies of the samples show an improvement in interfacial adhesion between the NBR and SBR phases in the presence of the prepared compatibilizing agents. The authors also reported the samples with grafted compatibilizers showed superior crosslink density and thermal stability, as compared to the blends without graft copolymers. ... 

The role of solvent alcohol in the photosensitized copolymerization or graft polymerization of styrene with cellulose has been investigated. Photo-induced grafting of poly(styrene-a/r-acrylonitrile) to cellulose yielded a product containing hetero- and homo-polymer chains. The effects of the matrix and concentration on the rate of reaction and the products have been investigated in persulphate-initiated grafting of poly(styrene-a/t-acrylonitrile) onto cellulose. ... 

Kamel, S., Hassan, E. M., and El-Sakhawy, M. 2006. Preparation and application of acrylonitrile-grafted cyanoethyl cellulose for the removal of copper (II) ions. /. Appl. Polym. Sci. 100 329-334. 

By using this technique acrylamide, acrylonitrile, and methyl acrylate were grafted onto cellulose [20]. In this case, oxidative depolymerization of cellulose also occurs and could yield short-lived intermediates [21]. They [21] reported an electron spin resonance spectroscopy study of the affects of different parameters on the rates of formation and decay of free radicals in microcrystalline cellulose and in purified fibrous cotton cellulose. From the results they obtained, they suggested that ceric ions form a chelate with the cellulose molecule, possibly, through the C2 and C3 hydroxyls of the anhy-droglucose unit. Transfer of electrons from the cellulose molecule to Ce(IV) would follow, leading to its reduction... 

Graft copolymerization of acrylonitrile with various vinyl comonomers such as methyl acrylate, ethyl acrylate, vinyl acetate, and styrene onto cellulose derivatives using ceric ion was studied [24]. The results showed that... 

The photo-induced process of modification of cellulose and its derivatives was reported by Geacintov and coworkers [67,68]. Thus, acrylonitrile, vinyl acetate, styrene, MMA, and the binary system of styrene and AN were grafted onto cellulose and cellulose derivatives. In... 

Improvement in the solvent and oil resistance of rubbers can be achieved via grafting of acrylonitrile onto rubber [140-142] and rubber blends [143]. The careful control of the degree of grafting allows vulcanized rubber with high-mechanical properties compared with ungrafted vulcanized rubber to be obtained. Also, acid resistance [144] and resistance to microbiological attack [145,146] was improved for cellulose grafted with acrylonitrile, and increases in base resistance were also noted for MMA and a mixture of MMA and ethyl acrylate [13],... 

Partial carboxymethylation of wood pulp significantly increases its susceptibility toward grafting with acrylonitrile using the ceric ion as the initiator 146]. Studies dealing with grafting of various vinyl monomers, such as acrylonitrile, methylmethacrylate, and acrylamide, onto partially carboxymethylated cotton cellulose using tetravalent cerium as the initiator have been reported [47]. 

An effective method of NVF chemical modification is graft copolymerization [34,35]. This reaction is initiated by free radicals of the cellulose molecule. The cellulose is treated with an aqueous solution with selected ions and is exposed to a high-energy radiation. Then, the cellulose molecule cracks and radicals are formed. Afterwards, the radical sites of the cellulose are treated with a suitable solution (compatible with the polymer matrix), for example vinyl monomer [35] acrylonitrile [34], methyl methacrylate [47], polystyrene [41]. The resulting copolymer possesses properties characteristic of both fibrous cellulose and grafted polymer. 

Deters (14) grafted acrylonitrile, methyl methacrylate and vinyl chloride on cellulose and cellulose triacetate. The first two monomers were put in the reactor as liquids, the last as a gas. The results are summarized on Table 1. Vinyl chloride did not graft to cellulose (14). 

The first application of the ferrous ion-hydrogen peroxide initiation for polymerizing vinyl monomers on and into cellulose fibers has been reported by Landeias and Whewell (41) in three successive papers. They are apparently the first who applied the "anchored catalyst technique, which other people have termed "in situ polymerization to cellulose grafting. The authors internally deposited methyl methacrylate, acrylonitrile, styrene, methyl vinyl ketone and methacrylamide in amounts between 10 and 80%. No attempt had been made to determine if actual grafting had occurred. In 1961 Richards (42) studied this question in great detail. Products obtained by polymerization of acrylonitrile and of styrene in viscose rayon were acetylated. Fractionation of... 

Daniel, Moore, and Segro (49) further investigated the graft polymerization of acrylonitrile to paper. They found that in grafted products having add-ons up to 53% neither cellulose nor polyacrylonitrile could be extracted with respective solvents. 

Guzman (53) investigated the ceric ion initiated grafting of acrylonitrile, acrylamide, methyl methacrylate, styrene, vinyl acetate, methacrylate, acrylic anhydride, and isoprene to cellulose. Intense grafting was obtained with acrylonitrile, acrylamide, methacrylate and acrylic anhydride. 

In a few cases other redox systems are recommended to initiate grafting to cellulose. Asahi Chemical Industries (62) was granted a patent to graft acrylonitrile to viscose rayon fibers using ferrous sulphate and sodium formaldehyde-sulphoxylate as initiator. 

Already in 1955 Polymer Corporation (63) had applied for a patent on a process of treating naturally occurring polymeric substances or their derivatives with ozone containing inert gases and subsequently contacting the ozonized substrates with polymerizable monomers. In the presence of redox activators butadiene, acrylonitrile, and styrene were grafted onto cellulose, starch, casein, gelatin, and rubber. 

Kargin, Usmanov, and Aikhodzhaev (64) used a similar technique of ozonization to introduce hydroperoxide groups into cellulose substrates. They observed grafting of styrene to ozonized viscose tire cord even without the presence of any other initiating system imparting improved rubber-adhesion to the rayon tire cord. In a later report, Usmanov, Aikhodzhaev, and Azizov (65) described the grafting of acrylonitrile, methyl methacrylate, methylvinylpyridine, and of vinylacetate onto ozonized cellulose. 

---