Investigation of the Optical and Structural Properties of Bio-polymeric Fibers

Abstract

This thesis contains four chapters

Chapter one concerned with a general introduction and previous studies on the interferometric methods used for investigating the optical properties of fibers and brief information about the tissue, biomaterial, and surgical suture.

The second chapter was about techniques used for studying the optical properties and geometrical parameters of fibers. These techniques are multiple-beam Fizeau fringes in transmission, and laser diffraction method.

The third chapter has two main parts: The effect of thermal treatment on the physical properties of Novafil surgical suture and determination of its dispersion parameters. This chapter contains the result of experimental works that produced from the thermal treatment done on Novafil surgical suture. Samples of Novafil surgical sutures, which are Polybutester monofilaments, were thermally annealed at temperatures ranging from 50-130 ℃ for two different durations of 60 and 120 min. The thermal treatment carried out under fixed end conditions. The optical and structural properties of the tested sutures, such as their refractive indices, birefringence, polarizability, dielectric constant and dielectric susceptibility, determined by using multiple-beam Fizeau fringes in transmission, from the resulting data, there was a marked increase in the molecular orientation and crystallization process with annealing for 120 min, and this means a new reorientation of Novafil suture molecules was performed, which will improve the mechanical properties of the sutures. Also, this improvement is essential for these biodegradable materials to widen their medical use and develop their clinical results. Dispersion behavior plays a critical role in the characterization and performance of polymeric material. The interaction between light and matter leads to refraction effects. The refractive index varies with the variation of the incident light wavelength because of these interactions. This variation gives rise to the dispersion properties of Novafil surgical suture. Finally, the relation between the refractive index of Novafil surgical suture and the wavelength of the incident light investigated. The optical properties of fibers depend on the arrangement of the chain molecules.

In the last chapter, the mechanical properties of Novafil surgical suture which depend intensely on the degree of orientation determined by studying the influence of draw ratio on the direction of sutures and the accompanying changes with it; From the data produced in this chapter, some notes can be obtained: The stress-strain curve of Novafil surgical suture exhibited non-linear deformation behavior in which the strain rises at an increasing rate as the stress is raised and takes a J-shaped stress-strain curve. The molecular chains become more oriented as the drawing process continues. As the drawing process progressed, the fringe shifts deformed, and the suture samples become thinner, this means that there is a change in the arrangement of molecules inside the suture material and their refractive indices. The involvement of opto-mechanical data and stress-strain relationships would provide surgeons with needed criteria for better suture selection. Besides, polymer scientists would have a common ground for the future development of suture's properties.