Grafting rate, solvent effects

Solvent Effects on Grafting Rate and Surface Properties. 

There are a number of important factors that must be considered before applying gamma radiation-induced grafting. These factors include the radiation sensitivity of the polymer/monomer system, radiation dose and dose rate, type and concentration of inhibitor, type of solvent or diluent, and monomer concentration. The effect of such parameters on the grafting efficiency during mutual grafting is given below. 

Table Base Solvents (S) 4. Summary of Solvent Film 0PP, Monomer AM, S - 0PP BP 3 + S interaction reaction Effects on Surface Photografting. Sensitizer BP, Irradiation at 366nm. Surface Rate of Proposed structure concentration grafting of grafted 0PP film of polyAM ...

The parameters which predominantly influence the acid effect in radiation grafting of styrene monomer to polyethylene film are the structure of solvent, the concentration of monomer and the dose rate. Because these three variables are inter-related, it is difficult to predict, a priori, the conditions required to yield an optimum in grafting. In this respect the type of solvent used is particularly important. 

Variables affecting the homopolymer yields in acid have been examined and include radiation dose, dose-rate and concentration of monomer in solvent. Water is shown to have a different effect to acid. M values on all homopolymers from the above runs are lower in acid than in neutral solution. The significance of the molecular weight data in grafting and homopolymerisation is discussed especially with respect to possible commercial applications of the graft copolymers of cellulose. 

The preparation of pol)rmeric catalysts and substrates containing imidazole groups and nitro-phenyl esters, respectively, grafted onto crosslinked polystyrene beads has been described and the effects of the acyl chain length in the substrate in the aqueous alcohol solvent systems on the rate of hydrolysis of 3-nitro-4-acyloxybenzoic acid substrates catalyzed by insoluble catalysts were determined. 

The effects of solvents on the rates of initiation can have considerable implications for radiation grafting. This v as clearly shown for the grafting of styrene to cellulose acetate in solution (4). The use of pyridine with a 0 compared with cinethyl... 

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