14854
Initially a series of poly ( 2 - methyl - 2 - acrylamidopropanesulfonate - co - acrylic acid ) ( poly ( AMPS - co - AA ) ) ( 1 : 8 to 1 : 1 mol : mol ) , poly ( styrenesulfonate - block - acrylic acid ) ( 2 . 4 : 1 mol : mol ) , and poly ( styrenesulfonate - alt - maleic acid ) ( 3 : 1 mol : mol ) copolymers were screened for solubility in API brine at 90 degrees C .
 poly ( 2 - methyl - 2 - acrylamidopropanesulfonate - co - acrylic acid ), poly ( AMPS - co - AA ), poly ( styrenesulfonate - block - acrylic acid ), poly ( styrenesulfonate - alt - maleic acid )
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 poly ( 2 - methyl - 2 - acrylamidopropanesulfonate - co - acrylic acid ), poly ( AMPS - co - AA ), poly ( styrenesulfonate - block - acrylic acid ), poly ( styrenesulfonate - alt - maleic acid )