Thermal, mechanical, and rheological properties of poly(ε‐caprolactone)/halloysite nanotube nanocomposites

Abstract

Naturally available halloysite nanotubes (HNTs) with hollow nanotubular structures were used as reinforcement in poly(e-caprolactone) (PCL). The PCL/HNT nanocomposites were prepared by melt mixing the polymer with as-received HNTs up to 10 wt % in an internal batch mixer. Transmission electron microscopy analysis indicated that the HNTs were dispersed uniformly on the nanoscale throughout the PCL matrix. Differential scanning calorimeter studies revealed that the PCL crystallinity was decreased in the nanocomposites, and the HNTs dispersed in the PCL matrix led to an increase in the non-isothermal crystallization temperature of the PCL. Tensile and dynamic mechanical tests showed great enhancement in strength and stiffness at low HNT content, while still maintaining the ductility of the PCL. The glass transition temperature (T g ) of the pristine PCL was substantially increased with increase in filler loading, which indicates good reinforcing effect imparted by the addition of HNT. Melt rheological studies revealed that the nanocomposites exhibited strong shear thinning behavior, and a percolated network of HNT particles was formed.

Escalating Applications of Halloysite Nanotubes

“…The maximum contact angle for the HNTs-PP composites was near to 170• with 15 wt.% 52 . But in HNTs-pectin and HNTs-PCL nanocomposites water contact angle was decreased by HNTs 16,49 . For the HNTs-HPC nanocomposite films an increase in the water contact angle was observed 49 .…”

“…The crystallinities of the HNTs-PLA composites were significantly superior to neat PLA. The HNTs-PCL nanocomposites showed higher crystallization temperatures 16 .…”

“…HNTs also improved the tensile strength and Young's modulus of the chitosan 13,14 and PVA 15 nanocomposites films. The mechanical properties of PCL 16 , PLGA nanofibers 17,18 and EPDM [19][20][21] also improved by the addition of HNTs. HNTs-PLA bionanocomposites have better properties with HNTs contents 22,23 .…”

“…HNTs can affect the crystallization behavior of PVA 15,51 , PLA 22,23 , PP 52 , PA6, PVDF 36 , and PCL 16 . The crystallization temperature of the HNTs-PVA initially increased but further loading decreases the improvement in the crystallization temperature 51 .…”

Effect of halloysite on structure and properties of melt-drawn PCL/PLA microfibrillar composites

“…In this area, application of various nanofillers (NF) leading to simultaneous reinforcement, compatibilization, and improvement of other material parameters may also be beneficial [8][9][10][11][12]. Recently, halloysite nanotubes have been successfully applied to modification of PLA [13,14] and PCL [15,16]; their advantage is dispersion even without organophilization in these polar polymers. In some cases, suitable modifications can enhance HNT efficiency [17,18].…”