16572
Utilizing tin ( II ) bis ( 2 - ethylhexanoate ) , aluminum salan , and aluminum salen catalysts , the copolymers were synthesized through the ring - opening polymerization of d - , l - , rac - , or a blend of l - and rac - lactide using monomethoxy - poly ( ethylene glycol ) as a macroinitiator .
 Chemical: tin ( II ) bis ( 2 - ethylhexanoate ); Chemical: aluminum salan; Chemical: aluminum salen; Chemical: l - and rac - lactide; Chemical: monomethoxy - poly ( ethylene glycol )
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: tin ( II ) bis ( 2 - ethylhexanoate ); Chemical: aluminum salan; Chemical: aluminum salen; Chemical: l - and rac - lactide; Chemical: monomethoxy - poly ( ethylene glycol )