New Hybrid Materials Based on Modified Halloysite and Unsaturated Polyester Resin

Abstract

New hybrid materials based on unsaturated polyester resin and modified halloysite with different coupling agents were synthesized. The effect of functional groups grafted on the surface of halloysite against the properties of the final hybrids was studied using different characterization methods. The results of dynamic mechanical analyses showed that the glass transition temperature value of hybrids was strongly influenced by the halloysite modifier type. The concentration of halloysite and the modifier agent type influence the thermal stability of final hybrid materials.Keywords Halloysite; Hybrid materials; Unsaturated polyester resin; X-ray photoelectron spectroscopy INTRODUCTIONRecently the halloysite nanotubes (HNT) were used as nanofillers in polymer matrices and monomers such as linear low density polyethylene (LLDPE), polystyrene, polypropylene, epoxy resin, elastomers, natural rubber and ethylene propylene diene monomer (EPDM) .HNT represents a natural clay with a chemical structure similar with the kaolin minerals but with a distinct morphology. HNT exhibit different morphology depending on the soil from which they are extracted. The most interesting morphology of HNT is hallow nanotubular structure characterized by 20-50 nm in diameter and several hundreds nanometers in length [1] .As other layered silicates, halloysite in the natural state exhibits a high hydrophilic behavior and therefore a low compatibility with polymer matrix like epoxy resins, unsaturated polyester resins. In the case of layered silicates like montmorillonites which exhibit high cationic exchange capacity (CEC) value the compatibilization step of inorganic compound with organic matrix was done by a cationic exchange process between silicate and protonated

Functionalization of Porous Clay Heterostructures with Silane Coupling Agents

“…The modification of PCH with silane coupling agents (APTES and GPTMS) was highlighted by the apearance of new peaks at 2927 cm -1 (APTES) and 2951 cm -1 (GPTMS) attributed to the streaching vibrations of C-H from CH 2 groups of the coupling agents. Similar results were reported for various inorganic clays (halloysite, montmorillonite, kaolinite, MCM) modified with silane coupling agents [9,[14][15][16].…”

Preparation of halloysite nanotubes supported 2-mercaptobenzimidazole and its application in natural rubber

“…Typically, the outer diameter and inner diameter of HNTs are about 10-50 nm and 5-20 nm, respectively, while the length of HNTs is about 0.5-2 lm. HNTs are an environmentally-friendly natural inorganic nanometer material [2], which has been widely used in polymers as inorganic filler to promote the properties of polymeric materials [3][4][5][6][7][8][9][10][11][12][13]. Accordingly, the dispersion of particulate nano-fillers in polymer matrix and the filler-rubber interaction are two critical factors in determining the ultimate performance of polymer/HNTs nanocomposites.…”

“…Halloysite nanotubes (HNTs) are one of a few natural nanomaterials, which are a type of natural silicates with nanotubular particles. Chemically similar to kaolin, HNTs have a molecular formula of Al 2 Si 2 O 5 (OH) 4 ÁnH 2 O. The nanotubular structure is evolved by rolling up the layers of kaolinite under natural conditions.…”

Halloysite Containing Thermoset Nanocomposites via Free Radical Photocrosslinking Polymerization

“…Halloysite-epoxy nanocomposites with improved particle dispersion were reported by Deng et al [38] and Ye et al [39] The results demonstrated that blending epoxy with 2.3 wt% halloysite nanotubes increased the impact strength by four times without scarifying flexural modulus, strength, and thermal stability. Indeed, Garea et al [40] used HNTs to improve the properties of unsaturated polyester resin (UPR). They modified HNTs with two coupling agents, triethoxyvinylsilane and γ-aminopropyltriethoxysilane.…”

“…Indeed, Garea et al. [ 40 ] used HNTs to improve the properties of unsaturated polyester resin (UPR). They modified HNTs with two coupling agents, triethoxyvinylsilane and γ‐aminopropyltriethoxysilane.…”