Properties and applications of nanoclay reinforced open-porous polymer composites Elif Y€ uce, 1 E. Hilal Mert , 1 Sinan S ¸en, 1 Semih Saygı, 2 Nevim San 2 1 Faculty of Engineering, Department of Polymer Engineering, Yalova University, Yalova 77100, Turkey 2 Department of Chemistry, Yildiz Technical University, Davutpasa Campus, Istanbul 34220, Turkey Correspondence to: E. H. Mert (E - mail: hmert@yalova.edu.tr) ABSTRACT: Open-porous nanoclay reinforced polymer composites were prepared via high internal phase emulsion templating using 1,3-butanediol dimethacrylate and surface modified montmorillonite (SM-MMT). Organophilic clay was obtained by using a reactive intercalant—quaternary cocoamine salt having a styryl group—for surface modification of MMT. The clay modification resulted in not only intercalated silicate layers but also nanoclay particles compatible with the continuous phase of the emulsions. It was found that increasing clay amount leads to formation of hierarchical porous structure accompanied with larger cavities and interconnected pores. In this respect, cavity size of the resulting composites was found to be altered between 6.78 and 8.82 lm. On the other hand, as compared to bare composites, addition of clay particles increased compressive modulus of the resulting materials from 26.4 to 72.5 MPa. The adsorption capacities of the porous composites for methyl violet 2B were investigated by batch experiments and discussed as a function of their SM-MMT loading. It was determined that, the dye adsorption of the composites increased with increasing nanoclay amount in the polymer matrix. Thus, the adsorption percentage of the composite loaded with 7 wt % nanoclay was found to be as high as 88%. V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45522. KEYWORDS: adsorption; clay; mechanical properties; morphology; porous materials Received 6 January 2017; accepted 9 July 2017 DOI: 10.1002/app.45522 INTRODUCTION High internal phase emulsion (HIPE) templated polymers (polyHIPEs) are known to have an advantage for easy prepara- tion of monoliths, 1,2 beads, 3,4 and membranes, 5,6 exhibiting well-defined hierarchical open-porous structures. HIPEs are concentrated emulsions where higher than 74 vol % of the emulsion contains the internal phase. 7,8 In most cases, deionized water is used as the internal phase while continuous phase con- sists of monomers. The polymerization of the continuous phase results in highly porous and interconnected crosslinked poly- meric foams—polyHIPEs. 9 Depending on their hierarchical porosity, easy control of pore sizes, permeability, and low den- sity, polyHIPEs offer advantages in many fields especially in adsorption, 1,4,10–12 ion exchange, 13,14 chromatography, 15,16 catal- ysis, 17,18 and tissue engineering. 19–21 However, their insufficient mechanical properties such as brittleness and chalkiness origi- nated from porous morphology prevent their use in major industrial applications. 22,23 PolyHIPEs were first prepared and patented by the Unilever researchers, Barby and Haq in 1985 from water-in-oil (w/o) HIPEs of styrene (St) and divinylbenzene (DVB). 8 Then, scientists applied several approaches to enhance mechanical properties of polyHIPEs such as by using different monomers that give flexibility and durability to the structure, increasing the crosslinking ratio, adding a suitable reinforcer to continuous phase and increasing the density of material. 22–26 In this respect, silica nanoparticles, 22,23 titania nanoparticles, and carbon nano- tubes 27,28 have been used to reinforce different polyHIPE matri- ces. Among them, montmorillonite and bentonite clays have been mostly used reinforcers for the preparation of high strength polyHIPE foams. For instance, Pakeyangkoon et al. prepared polyDVB polyHIPEs filled with porous clay particles by using organomodified bentonite and reported that presence of layered silicate in the polymer matrix resulted in improved compressive stress and Young’s modulus of the material up to 84% and 137%, respectively. 29 Abbasian and Moghbeli reported polyHIPE nanocomposites from HIPEs having styrene/acryloni- trile/organoclay and revealed that adding 3 wt % of hydrophilic organoclay to the polymer matrix improved crush strength sig- nificantly. 30 Recently, Alikhani and Moghbeli reported polyHIPE nanocomposite foams from the polymerization of organically modified montmorillonite containing vinylbenzyl chloride/ divinylbenzene (VBC/DVB) HIPEs. 13 In this study, they showed V C 2017 Wiley Periodicals, Inc. WWW.MATERIALSVIEWS.COM J. APPL. POLYM. SCI. 2017, DOI: 10.1002/APP.45522 45522 (1 of 10)