Masatsugu Mochizuki

Studies on biodegradable poly(hexano-6-lactone) fibers. Part 3. Enzymatic degradation in vitro (IUPAC Technical Report)

Poly(hexano-6-lactone) (PCL*) fibers were enzymatically degraded by a hydrolase in vitro. The extent of degradation of PCL fibers was examined by weight loss, mechanical properties loss such as tensile strength and ultimate elongation decreases, and visual observations by scanning electron microscopy. The in vitro degradation of PCL fibers was carried out using a lipoprotein lipase (Lipase-PS) as a hydrolase. The kinetic study on the weight loss of PCL fiber accompanying the enzymatic degradation suggested that the degradation of PCL fibers gradually takes place from the surface, not bulk degradation. The rate of degradation was found to depend on draw ratio and crystallinity of the PCL fibers. The strength loss of PCL fibers in the course of degradation took place faster than the weight loss of PCL fibers. Sonic velocity measurements as well as dynamic mechanical properties of PCL fibers were also examined as a function of weight loss of sample fibers with Lipase-PS treatments. It was shown that sonic velocity and value of loss tangent d changed steeply for undrawn PCL fiber in the first step with enzymatic digestion.

Studies on Biodegradable Poly(Hexano-6-Lactone) Fibers. Part 2: Environmental Degradation

Poly(hexano-6-lactone) (PCL*) fibers were degraded under environmental conditions, including soil burial, sea water exposure, and activated sludge exposure. The extent of degradation was examined by weight loss, mechanical properties loss such as tensile strength and ultimate elongation decreases, and visual observations by scanning electron microscopy. The rate of degradation was found to depend on draw ratio and crystallinity of the PCL fibers with surface erosion of amorphous regions more readily than crystalline regions. The life time of highly-drawn PCL fibers when exposed to soil burial and seawater was evaluated from the view point of environmental applications. In terms of degradation mechanism of PCL fiber breakdown biodegradation seems to be the dominant reaction, that is hydrolysis reaction catalyzed by enzyme secreted by microorganisms.

Studies on the biodegradable poly(hexano-6-lactone) fibers 1. Structure and properties of drawn poly(hexano-6-lactone) fibers (Technical Report)

IResearch and Development Center, Unitika Ltd., 23, Uji-Kozakura, Uji, Kyoto 61 1, Japan *National Institute of Materials and Chemical Research, Tsukuba, bar& 305, Japan 31nstitute of Chemistry, Academia Sinica, Beijing 100080, China 4Changchun Institute of Applied Chemistry, Academia Sinica, Changchun, Jilin, China 5Research Institute for Advanced Science and Technology, Osaka Prefecture University, Sakai, Osaka 593, Japan 6Department of Material Chemistry, Kyoto University, Yoshida, Sakyou-ku, Kyoto 606-01, Japan ’4-1-5 Midoridai, Kawanishi, Hyogo 666-01, Japan

Biodegradable Fibers Made from Truly-Biodegradable Thermoplastics

The term “biodegradable fibers” has different meanings for different people. In this review, this term is used to refer widely to fibers which will degrade in biological environment, including any environment where in vivo or in vitro biological or biochemical processes are occurring, regardless of the degradation mechanisms.