STUDY OF THE
DISPERSION CAPABILITY OF AN IN-SITU BUBBLE STRETCHING METHOD USED FOR PREPARING
POLYMER NANOCOMPOSITES
Daming Wu *, Xiuting
Zheng, Qingyun Meng, Fuhua Zhu
P.R. China
Abstract
In-situ Bubble Stretching (ISBS) has been shown
to be an effective method for dispersing aggregated nanoparticles
in polymer melts. By using the fast expansion of bubbles under certain
conditions, a stretching rate as high as 
and elastic oscillations on the bubble wall can be obtained,
and this is effective in the dispersion of the aggregated nanoparticles.
In this paper, the dispersion capability of ISBS was simulated using a
mathematical model taking into account the foaming conditions and the
properties of the polymers. FE-SEM measurements indicate that Mg(OH)2
nanoparticles in an LDPE located 35 μm away from the bubble surface can be dispersed to a
size of 100 nm, which is identical to the simulation. Upon removing the bubbles
by grinding, no re-agglomeration of the nanoparticles
was observed. The mechanical strength of the LDPE/nano-Mg(OH)2
composites prepared by ISBS, followed by removal of the bubbles reaches a
maximum when 15 phr of nano-Mg(OH)2
was added. Compared to the pure LDPE, the increase in the tensile strength can
be as high as 65%.
Keywords: in-situ bubble stretching, dispersion, distribution