Degradation of PGA, prepared by reactive extrusion polymerization, in water, humid, and dry air, and in a vacuum
- PDF / 1,120,109 Bytes
- 11 Pages / 584.957 x 782.986 pts Page_size
- 82 Downloads / 167 Views
Degradation of PGA, prepared by reactive extrusion polymerization, in water, humid, and dry air, and in a vacuum Shuliang Chen1 , Xin Zhang2, Mingyang He2, Jinchun Li1,a) 1 School of Materials Science and Engineering, Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials, Changzhou University, Changzhou 213164, China 2 College of Petrochemical Engineering, Jiangsu Key Laboratory of Green Catalytic Materials and Technology, Changzhou University, Changzhou 213164, China a)Address all correspondence to this author. e-mail: [email protected]
Received: 2 December 2019; accepted: 26 May 2020
Polyglycolide (PGA) materials have been widely used in the medical field, but the degradation mechanism in the natural environment is still unclear. High-viscosity PGA was prepared by using twin-screw reaction extrusion polymerization. The mass and intrinsic viscosity of PGA samples, the pH of the solution surrounding the PGA samples in water, and the number of degradation products resulting from the degradation of the PGA samples were studied under different conditions and at different temperatures. PGA does not degrade at 70 °C in either dry air or in a vacuum. Infrared spectroscopy (FTIR) and differential spectroscopy revealed that the PGA samples in water at 70 °C for 40 days had a substantially reduced mass and substantially altered thermal behavior when compared with the control sample (undegraded PGA sample). The degradation of the PGA samples in humid conditions at 70 °C was similar to the degradation of the samples in water at 70 °C. The results of this study indicate that water and water vapor (moisture) in the natural environment are the main causes of PGA degradation, and higher temperatures accelerate the degradation process, which shortens the shelf life and life of PGA.
INTRODUCTION With the wide-spread application of polymer materials, the “white pollution” it causes has become one of the most significant environmental problems affecting the survival and development of human beings [1]. The discovery and application of polyglycolide (PGA) is one method to solve the issues of “white pollution” caused by polymer materials [2]. PGA, also known as polyglycolic acid, is a crystalline polyester material with high structural crystallinity, excellent mechanical properties, biocompatibility, and it is biodegradable [3, 4]. In recent years, there have been many studies on how to synthesize PGA [5, 6, 7]. Different PGA research groups point out that traditional synthetic methods have many shortcomings. Due to the influence of the purity, price, and yield of the raw material glycolide, and the more complicated synthesis method and longer synthesis process time, it is difficult to obtain a higher intrinsic viscosity value for PGA. Low intrinsic viscosity PGA, prepared by traditional synthetic methods, is mainly
© Materials Research Society 2020
used in medical applications. Examples are bone scaffolds, biological scaffolds, and surgical sutures [8, 9, 10]. The latest process for synthesizing PGA uses glycol
Data Loading...
