Effect on grafting reactions

The dose rate affects both the yield and chain length of the grafted material. Air has a detrimental effect on grafting since it inhibits the reaction, which is consistent with other radiation-induced free radical reactions. Increasing the temperature of fhe graffing sysfem increases the yield. This is very likely because raising the temperature increases the diffusion rate of the monomer into the substrate. ... 

Table V. Effect of Initiator Concentration on Grafting Reaction with BPO as Initiator...

Table VII. Effect of Reaction Time on Grafting Reaction...

The same authors (5) showed also in another work that the presence of larger amounts of lignin in bisulfite pulps may have a favourable effect on grafting polyacrylonitrile using the cellulose xanthate-hydrogen peroxide redox system to initiate the copolymerization reaction. The plots of the total conversion as well as of polymer loading show a minimum centered around approximately 15% of lignin. 

Two polysaccharides isolated from the tissue cultures of ginseng and cultivated ginseng root caused, at a concentration of 20 and 40 mg/kg i.v. injection, a marked increase in spleen weight, enhanced the carbon clearance rate in mice and significantly promoted the production of serum specific antibody hemolysins as well as the IgG level in mice. They also enhanced DTH of footpad induced by SRBC in mice, but had no effect on graft-versus-host-reaction (GVHR) in mice [69]. 

The grafting of acrylonitrile and styrene on poly(e-caprolactam) was carried out in the liquid state [24, 37]. The more important parameters were monomer concentration and the milling time. In order to separate the effect of total liquid and of monomer concentration, the reactions were also conducted in solution. Monomer concentration in the range 25-100% had only a minor effect on the reaction (see Fig. 5.8) caused by milling 48 hr at 20°C,... 

Cotton linters and viscose grade wood pulp were grafted with acrylamide using the xanthate method. The effects of monomer concentration, reaction time, hydrogen peroxide concentration, reaction temperature, and liquor ratio on the grafting process were studied. Optimum conditions for the grafting reaction were established [26]. 

The effect of the reaction temperature on the grafting process is discussed. Upon increasing the reaction temperature from 15°C to 40°C the grafting decreases from 30.7% to 29.1% and from 30.0% to 28.5% for cotton linters and viscose wood pulp, respectively. This can be... 

The structural effect of alkyl groups such as methyl, ethyl, and -butyl on the Rp is small. Alkyl 4-methyl-phenylcarbamate can be chosen as a model compound for the hard segment of poly(ether-urethane) (PEU). This group can initiate grafting reaction with Ce(IV) ion and the grafting site was proposed at the hard segment of PEU [3,15] as shown in Scheme (1). 

DWORJANYNETAL. Effects of Additives on Grafting and Curing Reactions 113... 

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