3037
Four graft lengths were investigated , and the molar masses of the four free polymers ( 21 <= M ( n ) <= 100 kDa ; 1 . 07 <= D ( M ) <= 1 . 26 ) , i . e . the polymers subsequently employed in the grafting - to reaction , were shown to be in the same range as the molar masses of the polymers grafted from the surface ( 23 <= M ( n ) <= 87 kDa ; 1 . 08 <= D ( M ) <= 1 . 31 ) .
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Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
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