21382
Three chemical modifications increased the glass transition temperature of the polymer : ( a ) substitution of n - butyl by t - butyl groups , ( b ) reduction of the dimethylaminoethyl methacrylate ( DMAEMA ) content , and ( c ) incorporation of a bulky isobornyl repeating unit .
 Chemical: n - butyl; Chemical: t - butyl; Chemical: dimethylaminoethyl methacrylate; Chemical: DMAEMA; Chemical: isobornyl
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: n - butyl; Chemical: t - butyl; Chemical: dimethylaminoethyl methacrylate; Chemical: DMAEMA; Chemical: isobornyl