Degree of grafting

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],... 

Polymer Degree of grafting (mmol/100 g) % 0 to total C % Si to total C... 

Greco et al. [50] studied the effect of the reactive compatibilization technique in ethylene propylene rubber-polyamide-6 blends. Binary blends of polyamide-6-ethylene propylene rubber (EPR) and a ternary blend of polyamide-6-EPR-EPR-g-succinic anhydride were prepared by the melt mixing technique, and the influence of the degree of grafting of (EPR-g-SA) on morphology and mechanical properties of the blends was studied. 

Figure 8 Charpy resilience (R) as a function of test temperature for PA-6 homopolymer and PA-6-EPR binary blends with increasing degree of grafting (DG), 0-0%, -0.6%, A-2.4%, and B-4.5% DG. Source Ref. 61.

Notes q is the degree of grafting N is the number of grafted PMBA chains. 

In summary, the attributes of the elastomer that contribute to the enhanced impact strength of a plastic in plastic mbber blend include the type of mbber, plastic to mbber ratio, particle size, particle size distribution, cross-Unk density, and degree of grafting, if any. Molecular weight and molecular weight distribution of the plastic also exert some influence. For example, for high-impact PS, the optimal molecular weight of PS is between 170,000 and 220,000. The dispersity index is... 

The y-radiation-induced grafting of diethylene glycol dimethacrylate and its mixture with (3-hydroxy ethyl methacrylate in ethanol-water systems onto silicone rubber has been reported [ 164]. The grafting yield increases as the radiation dose, concentration of monomer and concentration of transfer agent increase. At the same radiation dose, the degree of grafting decreases, as the dose level increases. However, at the same dose rate, the grafhng level increases with radiation dose. 

The effect of propylene content on the EB radiation grafting of AA onto EPR to obtain hydrophilic elastomers has been investigated. Degree of grafting has been found to increase with the addition of alcohol (methanol and 1-propanol) into water as solvent for grafting which occurs easily in EPR of lower propylene content of 22% [376]. 

Fig. 24. LS at zero concentration for solutions of ny-lon-6/acrylic acid copolymers prepared by radiation grafting1 os The degrees of grafting are (a) 0.038, (b) 0.056, (c) 0.123...

After the irradiation, the surface of the film was wiped with a soft cloth wetted with acetone, dried under vacuum at 40°C for 10 hours and weighed. The degree of grafting (Dg) was determined by the equation (1). 

---