Mechanical properties
Mechanical properties were determined for suits obtained by wet phase
inversion using a PVP blowing agent and those obtained using nanofibers.
The obtained results were compared with the properties measured for a
suit with PLA without the use of a blowing agent (Table 4). Stress
curves of scaffoldings obtained without blowing agent both from PLLA and
from PCL were characteristic for durable, hard materials, with yield
stress. [60]
A higher Young’s modulus was observed in scaffolds without porophores
with PLLA (271.7 ± 17.1 MPa) than with PCL (48.2 ± 3.3 MPa) (Fig. 8). It
was similar in the case of maximum stress where a higher value (9.46 ±
0.59 MPa) was obtained for PLLA than for PCL (5.68 ± 0.85 MPa). In
contrast, scaffolds made of PCL (647.6 ± 91.6%) showed a higher maximum
relative elongation than PLLA (77.2 ± 5.3%). All scaffolds tested
exhibited excellent mechanical properties (E> 10 MPa),
while scaffolds made of PLLA were more flexible than those made of
PCL.[61] PLLA scaffolds with PVP (124.5 ± 20.8 MPa) and PCL
scaffolds with PVP (8.7 ± 1.3 MPa) were smaller Young’s modulus.
All scaffolds obtained with the participation of nanofibers had a stress
curve characteristic for elastic materials without a yield
point.[60] In PLLA scaffolds obtained with the addition of non-woven
fabric made of gelatin, Young’s modulus was 231.6 ± 70.4 MPa, the
maximum stress was 7.31 ± 0.07 MPa, and the maximum strain was 6.1 ±
0.7%.
Table 4 Comparison of mechanical properties of selected suits
that best meet the requirements for cartilage tissue regeneration.