9101
Despite the potential benefits of photopolymerization-based additive manufacturing , photochemical reactions in free-radical polymerization rarely proceed to completion , leading to the accumulation of residual monomer in polymer networks .
 photopolymerization-based, additive manufacturing, photochemical, polymerization, residual, monomer, polymer
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 photopolymerization-based, additive manufacturing, photochemical, polymerization, residual, monomer, polymer