The introduction of ANS into the XNBR latex dispersion
increased the dispersion stability due to an increase of molecular repulsion between both colloidal species. However, the tensile
strength of the latex films filled with ANS decreased, but increased
in films elongation at break. These phenomena are related to the
formation of the starch crystal region, which provide molecular
flexibility to deform upon stress, but prevent the formation of a
rubber coalesce region in the cured XNBR latex film. The result
also indicates that the ANS/XNBR latex films aged faster than the
control XNBR latex films due to the thermo-oxidative ageing in
the XNBR latex macromolecules and the pyrodextrination process
of starch chain. Digital microscope images show the formation of
starch crystal region on the ANS/XNBR latex surfaces, as well as
the characteristics of the microbial colony infection on the films.
The images show that the ANS/XNBR latex films could support the
growth of a microbial colony during the biodegradation test. SEM
images depicted the presence of a microbial strain in the cracking region of the biodegraded ANS/XNBR latex films which further
support the claim for the feasibility of the ANS/XNBR latex films to
biodegrade. The incorporation of ANS into the XNBR latex increased
the films T which indicate that higher thermal energy is needed
to degrade the materials. This is due to the introduction of the acrylonitrile functional group which provides further resistance for the
films against thermal deterioration.
Acknowledgements
The authors would like to acknowledge the support from
Synthomer (M) Sdn. Bhd for providing the XNBR X6322 latex,
the financial assistance from Universiti Sains Malaysia through
a research grant (grant no.: 203/PBAHAN/6740016) and the laboratory equipment provided by the School of Materials and
Mineral Resources Engineering, Engineering Campus, Universiti
Sains Malaysia.
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