Synergistic effect of plasma‐modified halloysite nanotubes and carbon black in natural rubber—butadiene rubber blend

Abstract

Halloysite nanotubes (HNTs) were investigated concerning their suitability for rubber reinforcement. As they have geometrical similarity with carbon nanotubes, they were expected to impart a significant reinforcement effect on the rubber compounds but the dispersion of the nanofillers is difficult. In this work, HNTs were surface-modified by plasma polymerization to change their surface polarity and chemistry and used in a natural rubber/butadiene rubber blend in the presence of carbon black. The aim of the treatment was to improve the rubber-filler interaction and the dispersion of the fillers. A thiophene modification of HNTs improved stress-strain properties more than a pyrrole treatment. The surface modification resulted in a higher bound rubber content and lower Payne effect indicating better filler-polymer interaction. Scanning electron microscopy measurements showed an increased compatibility of elastomers and fillers. As visualized by transmission electron microscopy, the thiophene-modified HNTs formed a special type of clusters with carbon black particles, which was ultimately reflected in the final mechanical properties of the nanocomposites. The addition of HNTs increased loss angle. Figure 9. Temperature dependence of the (a) storage modulus (E 0 ) and (b) loss tangent (tan d) of the crosslinked rubber. ARTICLE WWW.MATERIALSVIEWS.COM WILEYONLINELIBRARY.COM/APP

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

“…In some cases, suitable modifications can enhance HNT efficiency [17,18]. However, the evaluation of the structure-directing potential of HNT in polymer [19][20][21][22][23] is in its infancy stage, especially in comparison with that of oMMT [24][25][26][27]. Although the application of PLA and other high performance polyesters in the form of short reinforcing fibres [28,29] in polymer-polymer composites could be a radical alternative to the use PCL/ PLA blends, a significant limitation of this method is the difficult dispersion of compliant fibres in the polymer matrix and their relatively poor adhesion to it [30].…”

A review: role of interfacial adhesion between carbon blacks and elastomeric materials

“…Prior to the plasma treatments, CFs were washed with trichloroethylene and drophobic polymers and improve their wettability and adhesion. It is generally known that the introduction of oxygen-containing polar functional groups on the CB surface by oxygen plasma treatment increases the interfacial adhesion between CBs and organic elastomers, such as butyl rubber (BR), NR, and NBR, which is polar rubber [67][68][69]. Table 1 shows the oxygen content of the CB surface in terms of O 1S /C 1S ratio after plasma surface treatment.…”

“…Plasma gases used for the surface treatment of polymers can be classified into inactive gases, such as argon, helium, and nitrogen, and active gases, such as ammonia and carbon tetrafluoride. For each type of gas, the surface is modified by the introduction of specific functional groups on the surface [67][68][69].…”

Halloysite nanotubes-polymeric nanocomposites: characteristics, modifications and controlled drug delivery approaches

“…2b) Grafting silanes via condensation between the hydrolyzed silanes and the surface hydroxyl groups of the HNTs [40] Increase the interfacial adhesion of the HNTs γ-glycidoxypropyltrimethoxysilane; 3-(trimethoxysilyl)propyl methacrylate [7,22] Surface modifier (introduce double bonds onto the surface of HNTs to form sites for polymerization) [45,46] Acid and heat activation Dehydroxylation of the structural aluminol groups: decrease of the adsorption capacity for cationic drug; HNTs becomes amorphous Structural rearrangement: changes in the pore structure and surface properties; remove the physically bounded water [18] Table II -Examples of purification, modification and functionalization process of halloysite nanotubes (HNTs).…”