4764
The selected polymer is poly ( lactic ) acid ( PLA ) , which is a biodegradable thermoplastic polyester derived from corn starch and is one of the most common polymers in the FFF process .
 polymer, PLA, thermoplastic, polyester, starch, polymers, FFF
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:
 polymer, PLA, thermoplastic, polyester, starch, polymers, FFF