21725
The phosphate - terminated branch of PEG was synthesized via a substitution reaction of the hydroxyl end groups using phosphoryl chloride .
 Chemical: phosphate; Chemical: PEG; Chemical: hydroxyl; Chemical: phosphoryl chloride
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: phosphate; Chemical: PEG; Chemical: hydroxyl; Chemical: phosphoryl chloride