22681
We examined this hypothesis by using alginate and poly ( acrylic acid ) ( PAA ) modified with a controlled number of methacrylic groups as model inflexible and flexible cross - linkers , respectively .
 Chemical: poly ( acrylic acid ); Chemical: PAA; Chemical: methacrylic
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: poly ( acrylic acid ); Chemical: PAA; Chemical: methacrylic