Page 63 - 00. Complete Version - Progress Report IPEN 2014-2016

Application of Ionizing Radiations | Progress Report 63

silicon dioxide may be viable alternative fill- 1.5 billion fruits
er for replacing talc as mineral filler in poly- by year in a culti-
amide 6 compounds. Thus, this work contrib- vated area of 2.7
utes to minimizing environmental problems million hectares,
by enabling the use of colloidal silicon diox- but the coconut
ide in the productive process. husk fiber has
not been used
Investigation of the effect of ionizing radiation much for indus-
on composites based on biodegradable trial applications.
Figure 25. Scanning Electron Mi-
polymers and coconut fiber Moreover, when croscopy (SEM) image of PCL:PLLA
considering an 20:80 (w:w) 10% of acetylat-
ed coconut fiber composite.
Product development and improvement has a application in
crucial role to play in the further development the medical field, it is necessary that the prod-
of the biodegradable polymers market. Bio- ucts are sterilized and, ionizing radiation is
degradable polymers can be found in a wide widely used to sterilize medical and surgical
range of end use markets. Continued progress devices. In this research, blends and compos-
in terms of product development and cost re- ites based on two commercial polymers: poly
duction is required before they can effectively (ε-caprolactone), PCL, and poly (lactic acid),
compete with conventional plastics for main- PLLA, and coconut fiber have been studied.
stream applications. And, the addition of natu- Samples were irradiated with gamma rays
ral fibers to polymer blends can lead to physical from 60Co source and, electron beam from
properties improvement and also can dimin- Dynamitron Accelerator, with radiation doses
ish cost. Additionally, it will reduce the amount ranging from 10 kGy up to 1 MGy. The non-ir-
of agribusiness waste disposal in the environ- radiated and irradiated samples were studied
ment. In Brazil, coconut production is around using several analytical techniques and char-
acterization assays that allowed understand-
ing their properties in order to enable their
Figure 26. Cytotoxicity results of PCL, PLLA
and composites with coconut fiber. application as precursors for medical and sur-
gical devices. Thermal processing used to ob-
105
tain composites and previous acetylation by
chemical treatment of coconut fibers contrib-
101 uted to the bioburden reduction. Furthermore,
reducing initial bioburden it was possible to
diminish radiation doses needed to perform
98
sterilization. Enzymatic and soil degradation
were not negatively affected by radiation pro-
94 cessing. Even though fiber incorporation to
the polymer blend slightly reduced degrada-
tion process, composites continued degrading
90 through time. Artifacts produced by means of
PCL 0k Gy PCL / PLLA 0 kGy PLLA 0 kGy bienda 10% acet 0kGy PEAD the materials studied here can be radiation
bienda 10% unt 0kGy
processed with doses up to 100 kGy without
prejudice of their biodegradability. Cytotox-
icity In vitro results of lixiviate indicated that