Annals of Warsaw University of Life Sciences - SGGW

Structural formulas of antioxidants (propyl gallate, etoxyquin and 2,4,5trihydroxybutyrophenone)
are presented in Fig. 1.
C
H 3
CH 2
O
CH 3
N
H
HO
HO
etoxyquin
CH 3
CH 3
OH
O
10
O
propyl gallate
CH 2
CH 2
HO
HO
CH 3
O
OH
CH 2
CH 2
2,4,5 - trihydroxybutyrophenone
Fig. 1. Structural formulas of antioxidants (propyl gallate, etoxyquin and 2,4,5-trihydroxybutyrophenone)
Accelerated ageing tests in air atmosphere
At the beginning non extracted and extracted pinewood from sapwood zone, cellulose
and cellulose with antioxidant (PG, THBP, EQ) were placed in desiccator with phosphorus
pentaoxide (P2O5) (anhydrous conditions). In this vessel samples were submitted to
accelerated ageing tests. Ageing tests were carried out in thermal chamber (KC 100/200,
Elkon company) at 130ºC. Samples were collected after 15 days and were prepared to FT-IR
analysis.
Accelerated ageing tests in nitrogen atmosphere
In this studies cellulose samples and samples of cellulose with antioxidant (PG, THBP,
EQ) were used only. They were placed in desiccator with P2O5. Vacuum pump was used to
remove the air to 6.6 mbar, then desiccator was filled with the nitrogen. The procedure was
repeated three times. After that, samples in desiccator were submitted to accelerated ageing
tests. Ageing tests were also carried out in thermal chamber (KC 100/200, Elkon company) at
130ºC. Samples were also collected after 15 days and were prepared to FT-IR analysis.
FT-IR analysis
Preparation of cellulose samples to analysis
Heat-treated (after 15 days) and untreated (control) cellulose samples were ground to
homogeneous powder. Disintegrated samples were embedded in potassium bromide (KBr)
pellets and were submitted to FT-IR analysis.
CH 3