title: Monitoring the degradation process of biopolymers by ultrasonic longitudinal wave pulse-echo technique.
abstract: A non-destructive ultrasonic longitudinal wave pulse-echo technique was utilized to monitor the degradation process of three biodegradable polymers: poly(glycolic acid) (PGA), poly(L-lactic acid) (PLLA) and 50:50 poly(D,L-lactide-co-glycolide) (PDLLG). The degradation processes of PGA and PLLA, which have different molecular structure, were also studied by differential scanning calorimetry (DSC). The degradation processes of PDLLG specimens prepared by different methods were characterized by the ultrasonic wave technique and gel permeation chromatography (GPC). The resulting acoustic and thermal properties indicate that PLLA and PGA exhibit distinctly different degradation behavior, whereas the acoustic properties and molecular weight of PDLLG are sensitive with preparation methods. The present study demonstrates that ultrasonic wave technique provides a powerful tool in detecting the property changes of biodegradable polymers prepared with different manufacturing process and that the degradation behavior of biodegradable polymers can be closely monitored by ultrasonic technique.
authors.affiliation: Department of Chemical Engineering, University of Southern California, Los Angeles, CA 90089-1211, USA.
authors.forename: Hsueh-Chang
authors.initials: HC
authors.lastname: Wu
authors.forename: Fu-Wen
authors.initials: FW
authors.lastname: Shen
authors.forename: Xuan
authors.initials: X
authors.lastname: Hong
authors.forename: Wenji V
authors.initials: WV
authors.lastname: Chang
authors.forename: Howard
authors.initials: H
authors.lastname: Winet
mesh_terms: D000162:Acoustics; D001672:Biocompatible Materials / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002845:Chromatography; D003460:Crystallization; D019344:Lactic Acid / Q000737:chemistry; D011091:Polyesters; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D001672:Biocompatible Materials; D001704:Biopolymers; D011091:Polyesters; D011108:Polymers; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)