Hydrolytic degradation behaviors of poly(p-dioxanone) in ambient environments

Abstract

The effects of temperature and relative humidity on the hydrolytic degradation of poly(p-dioxanone) (PPDO) were investigated. The hydrolytic degradation behaviors were monitored by tracing the changes of water absorption, mechanical and crystalline properties, molecular weight and its distribution, surface morphologies, as well as infrared absorption peaks and hydrogen chemical shifts during the degradation. It is found that the water absorption increases whilst the intrinsic viscosity, tensile strength and elongation at break decrease as the temperature or relative humidity increases. With degradation time growing, the molecular weight drops and its distribution broadens. The crystallinity of PPDO has a tendency to increase at first and then to decrease, while the crystalline structure is not significantly changed. At the same time, some cracks are observed on the surface and keep growing and deepening. All results show that temperature plays more significant roles than relative humidity during the degradation. The analyses of Fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy reveal that the degradation of PPDO is a predominant hydrolysis of ester linkages.

The influence of coexisted monomer on thermal, mechanical, and hydrolytic properties of poly(p‐dioxanone)

“…After 4 weeks, the cracks of PPDO/6PDO become much wider although it just appears on the surface of PPDO. The cracks appear on the surface of PPDO degradation samples have also been reported previously . As we known, PDO in PPDO/PDO mixture can leach out of the mixtures and dissolve in the solution, and it can convert to monomer acid which can catalyze the hydrolysis during the degradation process further.…”

“…Apparently, PPDO/PDO mixtures display a higher degradation rate. It has been reported that the temperature and relative humidity influence the hydrolytic degradation of PPDO . The increasing in crystallinity of PPDO is a consequence of the hydrolytic chain scission of unstable ester bonds and can be explained by the “cleavage‐induced crystallization” mechanism .…”

“…It has been reported that the temperature and relative humidity influence the hydrolytic degradation of PPDO. 37 The increasing in crystallinity of PPDO is a consequence of the hydrolytic chain scission of unstable ester bonds and can be explained by the "cleavage-induced crystallization" mechanism. 38 The degradation of PPDO first begins in the amorphous region and could be attacked easily by water, leading to a decrease in molecular entanglement; further these short segments could organize themselves to crystals at 37 8C above the T g of PPDO, therefore the crystallinity of PPDO first increases.…”

Sentry Bioconvertible Inferior Vena Cava Filter: Study of Stages of Incorporation in an Experimental Ovine Model

“…The tendency toward hypercoagulability in the sheep model was noted, and the investigators also noted that the sheep anatomy provided a greater challenge than in humans for deployment, due to extreme bending of the introducer sheath imposed by the groin geometry. The rate of hydrolysis of the PPDO filament is directly dependent on temperature, and human blood temperatures are lower than ovine blood temperatures [ 39 ]. Therefore, bioconversion times in an ovine model are not representative of device opening times in vitro, and while X-rays were performed during the animal studies to understand the process of bioconversion, the data collected were not used to establish the time to opening of the device.…”