Result and discussion
1. Characterization of DSNR
Fig.1. shows FT-IR spectra of NR and DSNR. It can be seen that extra absorption peaks at 1030, 1069 and
1279 cm
-1
were observed in DSNR. This indicates the phosphate groups which is present in the epoxidized natural rubber
molecules, as shown in Table 1. This proves the successful of the chemical reaction between ENR and dibutyl phosphate
to incorporate dioxaphospholane into the NR molecues.
Table 3
IR absorption bands characteristic of dioxaphospholane formation (Derouet
et al
, 2001)
Wavelength (cm
-1
)
Group
Literature values (cm
-1
)
1283
1064
1032
977
(RO)
3
P(O)
C-O-P
P(O)CH
2
R
P(O)CHR
2
1286-1258
1080-990
1042-987
1018-950
Fig. 1. FT-IR spectra of NR and DSNR.
2. Thermal stabilities
Thermal stabilities of NR, ENR and DSNR were characterized by TGA under nitrogen atmosphere, as
result shown in Fig. 2. It can be seen that NR, ENR and DSNR exhibited degradation temperatures (T
d
) of
approximately 374, 380 and 392
o
C, respectively. Therefore, the DSNR exhibited the maximum degradation temperature
because of dioxaphospholane groups attached in the NR molecules.
NR
DSNR
