{TAIL ~ The polyethylene glycol diamine} has {HEAD ~ the formula} NH2 x CH2 CH2 NH2, where x ranges from 2 to 6, and at least one of the dicarboxylic acids is an aromatic discarboxylic acid 
{ TAIL ~ The polyethylene glycol diamine } has { HEAD ~ the formula } NH2 x CH2 CH2 NH2 , where x ranges from 2 to 6 , and at least one of the dicarboxylic acids is an aromatic discarboxylic acid
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