Random and graft copolymers

Inui K, Okumura H, Miyata T, and Uragami T. Characteristics of permeation and separation of dimethyl acrylamide-methyl methacrylate random and graft copolymer membranes for a benzene/cyclohexane mixture. Polym Bull 1997 39 733-740. 

Four different forms alternating, block, random, and graft copolymers (see Text Fig. 19.14)... 

SYNTHETIC RANDOM AND GRAFT COPOLYMERS FOR UTILIZATION IN ENHANCED OIL RECOVERY—SYNTHESIS AND RHEOLOGY... 

A series of random- and graft-copolymers of acrylamide with varying molecular weights, shapes, ionic densities, and hydrogen-bonding capabilities have been synthesized and characterized. 

Nakano et al [160] prepared a copolymer of poly(vinyl acetate) and methacrylic acid by irradiation at 200 kHz. From measurements of viscoelasticity and from differential thermal analysis, it was concluded that the copolymer was of the block type. The glass transition temperature of this block copolymer was surprisingly reported to be much lower than those of random and graft copolymers. 

For copolymers, as a general rule, the more irregular and random the repeat unit arrangements, the greater is the tendency for the development of noncrystallinity. For alternating and block copolymers there is some likelihood of crystallization. However, random and graft copolymers are normally amorphous. 

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