Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 2020

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Comparison of thermal, structural and morphological properties of poly(l-lactide) and poly(l-lactide)/ hydroxyapatite microspheres for laser sintering processes

Krokos Anna, Gazińska Małgorzata, Kryszak Bartłomiej, Dzienny Paulina, Stępak Bogusz, Olejarczyk Michał, Gruber Piotr, Kwiatkowski Ryszard, Bondyra Agnieszka, Antończak Arkadiusz

Polimery

2020

T. 65, nr 9

605--612

A comparison of poly(l-lactide) (PLLA) and poly(l-lactide)/hydroxyapatite (PLLA/HAp) biocomposite microspheres fabricated by emulsion solvent evaporation technique designed for laser sintering (LS) applications is presented. Key properties such as thermal and structural as well as geometry, size distribution and powder flowability, which are crucial for this technique, are characterized to validate the applicability of microspheres for LS. The biocomposite microspheres turns out to be more suitable for the LS process than PLLA due to the higher thermal stability, broader sintering window and higher powder flowability.

Porównano właściwości mikrosfer z poli(l-laktydu) (PLLA) i z biokompozytu poli(l-laktyd)/ hydroksyapatyt (PLLA/HAp), przygotowanych metodą emulsyjną z odparowaniem rozpuszczalnika, przeznaczonych do procesu spiekania laserowego (LS). W celu weryfikacji przydatności mikrosfer do LS scharakteryzowano kluczowe dla tej techniki właściwości: termiczne i strukturalne oraz geometrię, rozkład wymiarów i sypkość proszku. Wykazano, iż mikrosfery biokompozytowe wykazują lepsze właściwości predestynujące je do przetwarzania metodą LS niż mikrosfery PLLA, w tym większą stabilność termiczną, szersze okno parametrów spiekania i większą sypkość proszku.

Laser-modified PLGA for implants: in vitro degradation and mechanical properties

Kobielarz Magdalena, Tomanik Magdalena, Mroczkowska Katarzyna, Szustakiewicz Konrad, Oryszczak Magdalena, Mazur Anna, Antończak Arkadiusz, Filipiak Jarosław

Acta of Bioengineering and Biomechanics

2020

Vol. 22, no. 1

179--192

Irradiations of poly(lactic-co-glycolic acid) surface by CO2 laser lead to alterations of physicochemical properties of the copolymer. Effects of PLGA irradiations depend on the process parameters determining different cases of surface modification. Hence the main goal of presented studies was to define the influence of CO2 laser irradiation with different process parameters, inducing three cases of surface modification, on mechanical properties and topography of PLGA during degradation in the aqueous environment. Methods: Hydrolytic degradation of untreated and treated by CO2 laser thin specimens of PLGA was performed in distilled (demineralized) water. Mechanical properties of PLGA specimens before and during incubation were conducted in accordance with the PN-EN ISO 527-3:1998 standard. The pH of incubation solutions, topographies, masses and geometrical dimensions of specimens were controlled during the process. Results: During the hydrolytic degradation, gradual changes in failure mode were observed from ductile failure characteristic for untreated PLGA to brittle failure of incubated PLGA regardless of the case of induced modification. Tensile strength decreased with degradation time regardless of the case of surface modification with insignificant fluctuation Young’s moduli at the level of means. The pH of solutions for each case decreased and topography od specimens become smoother with incubation time. Conclusions: PLGA surface modification by CO2 laser below the ablation threshold (P1) and at the ablation threshold (P2) led to surface functionalization, however, irradiation above the ablation threshold (P3) caused marked degradation of PLGA and accelerated specimens disintegration during incubation in the aquatic environment.