Suitable monomers for use as the first ethylenically unsaturated monomer containing {TAIL ~ a carboxyl acid} in above step a) include acrylic acid, methacrylic acid, ethylacrylic acid, crotonic acid, propiolic acid, styrene carboxyl acid, {HEAD ~ maleic anhydride}, and fumaric acid, etc 
Suitable monomers for use as the first ethylenically unsaturated monomer containing { TAIL ~ a carboxyl acid } in above step a ) include acrylic acid , methacrylic acid , ethylacrylic acid , crotonic acid , propiolic acid , styrene carboxyl acid , { HEAD ~ maleic anhydride } , and fumaric acid , etc
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH