Properties of unmodified and modified natural rubber/halloysite nanotubes composites

Halloysite Nanotubes (HNT) are chemically similar to clay, which makes them incompatible with non-polar rubbers such as natural rubber (NR). Modification of NR into a polar rubber is of interest. In this work, Epoxidized Natural Rubber (ENR) was prepared in order to obtain a composite that could assure filler–matrix compatibility. However, the performance of this composite was still not satisfactory, so an alternative to the basic HNT filler was pursued. The surface area of HNT was further increased by etching with acid; the specific surface increased with treatment time. The FTIR spectra confirmed selective etching on the Al–OH surface of HNT with reduction in peak intensity in the regions 3750–3600 cm−1 and 825–725 cm−1, indicating decrease in Al–OH structures. The use of acid-treated HNT improved modulus, tensile strength, and tear strength of the filled composites. This was attributed to the filler–matrix interactions of acid-treated HNT with ENR. Further evidence was found from the Payne effect being reduced to 44.2% through acid treatment of the filler. As for the strain-induced crystallization (SIC) in the composites, the stress–strain curves correlated well with the degree of crystallinity observed from synchrotron wide-angle X-ray scattering.

Download Full-text

Halloysite Nanotubes-Filled Natural Rubber Composite

10.1201/9781003220947-7 ◽

2021 ◽

pp. 135-158

Author(s):

Nabil Hayeemasae ◽

Hanafi Ismail

Keyword(s):

Natural Rubber ◽

Halloysite Nanotubes ◽

Rubber Composite

Download Full-text

Halloysite Nanotubes-Filled Natural Rubber Composite

10.1201/9781003220947-6 ◽

2021 ◽

pp. 111-134

Author(s):

Nabil Hayeemasae ◽

Hanafi Ismail

Keyword(s):

Natural Rubber ◽

Halloysite Nanotubes ◽

Rubber Composite

Download Full-text

Maleated Natural Rubber/Halloysite Nanotubes Composites

Processes ◽

10.3390/pr8030286 ◽

2020 ◽

Vol 8 (3) ◽

pp. 286 ◽

Cited By ~ 1

Author(s):

Nabil Hayeemasae ◽

Zareedan Sensem ◽

Kannika Sahakaro ◽

Hanafi Ismail

Keyword(s):

Tensile Strength ◽

Natural Rubber ◽

Large Strain ◽

Halloysite Nanotubes ◽

Maximum Torque ◽

Sem Images ◽

Filler Dispersion ◽

Dynamical Properties ◽

Improved Performance ◽

Maleated Natural Rubber

In this study, maleic anhydride (MA) grafted natural rubber (NR), known as maleated natural rubber (MNR), was melt-prepared with the MA content varied within 1–8 phr. MNR was used as the main matrix, with Halloysite Nanotubes (HNT) as a filler, in order to obtain composites with improved performance. The compounds were investigated for their filler–filler interactions by considering their Payne effect. On increasing the MA content, scorch and cure times increased along with maximum torque and torque difference. The MNR with 4 phr of MA exhibited the least filler–filler interactions, as indicated by the retention of the storage modulus after applying a large strain to the filled compound. This MNR compound also provided the highest tensile strength among the cases tested. It is interesting to highlight that MNR, with an appropriate MA content, reduces filler–filler interactions, and, thereby, enhances the HNT filler dispersion, as verified by SEM images, leading to improved mechanical and dynamical properties.

Download Full-text