Journal of University of Science and Technology Beijing
Volume 14, Number 6, December 2007, Page 1
Corresponding author: Chensha Li, E-mail: lichnsa@mail.tsinghua.edu.cn Also available online at www.sciencedirect.com
Materials
Effect of Co-polyester antistatic agent modified by carbon nanotubes
on the properties of polypropylene fibers
Chensha Li
1)
, Binsong Wang
2)
, Weizhe Lu
1)
, DazhiLi Wang
1)
, Zhi Li
1)
, Zechao Di
1)
, and Ji Liang
1)
1) Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
2) School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China
(Received 2006-12-03)
Abstract: Antistatic polymer fibers were investigated by using carbon nanotubes (CNTs) to enhance the antistatic ability of inner an-
tistatic agents based on the mechanism of attracting moisture by polar radical groups. It is indicated that the antistatic ability of the
fibers filled with composite antistatic agents that contain CNTs and organic antistatic agents was superior to that of the fibers filled
either with pure organic antistatic agents or pure CNTs. The antistatic ability of the composite antistatic agent fabricated by an in-situ
process was superior to that of the composite antistatic agent fabricated by direct dispersing CNTs in the antistatic agent carrier.
Moreover, the heat-treated CNTs could further enhance the antistatic effect compared with the initial CNTs. The antistatic effect is
significantly influenced by the content of CNTs in the composite antistatic agent.
Key words: carbon nanotube; polypropylene fiber; antistatic agent; in situ process
[This work was financially supported by the Major State Basic Research Development Program of China (No.10332020).]
1. Introduction
Polymer fibers with antistatic properties are neces-
sary to be developed because the electrostatic charge
of synthetic fibers leads to the attraction of dust, elec-
tric shocks, damages in electronic machines, and fire
hazard. When it is necessary to provide polymer fibers
with antistatic properties, the manufacturers have two
choices: either adding antistatic agents to the poly-
meric material or applying them onto its surface [1-3].
Because the inner antistatic agents are more durable
than outer antistatic agents, they become major re-
search directions of antistatic agents in plastics [4].
The classical antistatic agents are generally the “soap
like” molecules with a hydrophobic and a hydrophilic
part (fatty acid esters, ethoxylated amines, etc.), which
migrate to the surface and, by attracting a layer of wa-
ter, enhance the surface conductivity [4]. Such prod-
ucts are easy to be applied but have some important
drawbacks. They do not give volume conduction be-
neath the surface and are generally easy to be removed
and washed out, consequently limiting their effect
over time.
Permanency is an essential property in many appli-
cations. One approach is filling inorganic salts [5], by
which static charges are dissipated by the deliques-
cence of inorganic salts. The drawbacks of such ap-
proaches lie on the corrosion effect of the inorganic
salts on metallic devices. Moreover, the hand feeling
and extrinsic features of the polymer fibers may be
degraded by the filled inorganic salts. Conductive fil-
lers (carbon blacks, metallic fillers, or carbon fibers)
can also be a choice [6-7]. Mixed to the polymer ma-
trix, such fillers form a percolating, conductive net-
work inside the polymer matrix. The drawbacks lie on
large quantities of conductive fillers needed to form
transmission paths. Hence, the application range is of-
ten limited due to the reduction of the optical transpa-
rency and a decrease in mechanical properties. The
other favored type of the antistatic system is based on
a volume attracting moisture filler [8]. Added to the
polymer matrix, it forms a transmission network dur-
ing the processing. This type of antistatic system of-
fers the advantages of permanence, an ability to elim-
inate static charges, and volume conduction.
It is feasible to apply CNTs in the area of antistatic
polymers due to their nanometer diameters, unique
structure, conductance property, and high chemical
stability [9-11]. The suitable antistatic mechanism
should be considered if a study is aimed at enhancing
the antistatic ability of polymer fibers by CNTs. In this