| abstract |
Sequenced polymers are made by, first, the homopolymerization of a given quantity of the monomer in the presence of a radical catalyst, such as benzoylperoxide or oxidn. reduction catalyst such as NaHSO3, then adding to the reaction mixt. a quantity of a second monomer, continuing the reaction by copolymerization of the two monomers, then eliminating from the mixt. the residue of the first monomer, and continuing by homopolymerization of the second monomer. The prod. has a structure similar to AAA...AAA...BAB...ABA.. BBB...BBB. The residue of the first monomer is removed by a solvent which is immiscible with the reaction mixt. and is not a solvent for the second monomer. One of the monomers is lipophilic and the other is hydrophilic. The reaction does not require low temp. and is relatively simple. Used for making cosmetic prods. such as moisturizing cream, fluid creams, brilliantines and sun-tan cream. |