The effect of MWCNT on dynamic mechanical properties and
crystallinity of in situ polymerized polyamide 12
Iran Polymer and Petrochemical Institution,
Pazhouhesh Blvd., Pazhouhesh Science Park,
Km 15, Tehran‐Karaj Highway, Tehran, Iran,
Shervin Ahmadi, Iran Polymer and
Petrochemical Institution Pazhouhesh Blvd.,
Pazhouhesh Science Park, Km 15, Tehran‐
Karaj Highway, Tehran, Iran, 1497713115.
This work aims at investigating the dynamic mechanical properties of in situ anionic
ring opening polymerized polyamide 12 in the presence of multi‐walled carbon nano-
tubes (MWCNT). According to the dynamic mechanical thermal analysis results, the
addition of only 0.1 wt.% of MWCNTs led to 30% enhancement in modulus at room
temperature which exhibited improved mechanical behavior of the nanocomposites.
Test results showed that by the presence of 1.2% wt MWCNTs, the modulus is
almost doubled, and it did not show any tangible changes by the addition of more
nanotubes. Also, the effect of different frequencies on the viscoelastic behavior was
investigated in order to determine the thermal transitions occurred in the synthesized
nanocomposites. After that, the crystallinity of the samples has been studied using
differential scanning calorimetry and X‐ray diffraction data in order to investigate
the effect of MWCNT content on the crystals' dimension.
crystallinity, dynamic mechanical thermal analysis, in situ polymerization, multi‐walled carbon
nanotubes, polyamide 12
Aliphatic polyamides are engineering plastics. An important difficulty
during the usage of such polyamides is their hydrophilic character.
This feature is provided by the amide linkage. Increasing the number
units inhibits this matter.
They bring together good process-
ability and thermal stability, and also they are highly available in the
market. Commercially available polymers, such as Nylon (polyamide)
12 (PA12), rises, which can be easily produced by ring‐opening
polymerization of Laurolactam monomer.
PA12, the lowest water absorbing Polyamide, is associated with
excellent resistance towards solvents, abrasion, and environmental
stress cracking and high processability.
Polyamides (PA 12 and 11)
are often used as pressure sheaths for flexible pipes in oil exploration,
along with polyvinylidene fluoride and polyethylene.
Several additives, such as fillers, can be dispersed in the matrix, in
order to improve the mechanical properties of polyamide 12.
nanocomposites exhibit also reduced permeability to gases, enhanced
thermal stability, and improved stiffness and deformation properties.
One of the key research topics in the field of polymer materials is to
enhance the mechanical properties of polymers by incorporation of
The final properties of polymer composites depend on
both material composition and morphology obtained.
Multi‐walled carbon nanotubes (MWCNTs) are unique nanostruc-
tured materials indicating remarkable physical, mechanical, and
which make them attractive for many applica-
tions such as polymer composites.
The prospect of obtaining high‐
performance MWCNT‐based polymeric nanocomposites has attracted
the efforts of researchers.
MWCNTs have been successfully
compounded with different thermoplastic
ces through different conventional polymer processing technology.
There are varieties of nanocomposite materials which are normally
manufactured based on the applications.
According to the
acceptable performance of carbon nanotube (CNT), the synthesis of
nanocomposites based on polymer‐CNT is becoming increasingly
There are many studies carried on polymer‐CNT nano-
composites. The commercial products of polyamide 6 or polyamide
12 reinforced with MWCNT are available for applications such as
Received: 15 December 2017 Revised: 20 February 2018 Accepted: 22 March 2018
2134 Copyright © 2018 John Wiley & Sons, Ltd. Polym Adv Technol. 2018;29:2134–2146.wileyonlinelibrary.com/journal/pat