Kaolin Surface Research Articles

H-bonding supramolecular interactions driving the dispersion of kaolin into benzoxazine: A tool for the reinforcement of polybenzoxazines thermal and thermo-mechanical properties

Abstract The network structure of polybenzoxazines is known to be supported by strong inter- and intra-molecular hydrogen bonds. Kaolin, a platelet clay mineral, possesses similar supramolecular interactions, preventing its platelets from exfoliation when mixed with polymers. In the present study, demonstration of the ability of 3,3′-ethane-1,2-diylbis(3,4-dihydro-2H-1,3-benzoxazine) (EDBZ) to assembly onto kaolin surface through hydrogen bonding is given by Fourier transform infrared spectroscopy (FTIR). Composites were subsequently prepared by a convenient solventless method, leading to high performance materials with improved thermal and thermo-mechanical properties. As the improvement of the thermo-mechanical properties could be due to a catalytic effect of the clay interlayer cations, Sepiolite – a mineral clay with a similar cation exchange capacity than kaolin but with a far lower OH group content – was used to prepared composites. Similar crosslinking kinetics of EDBZ are obtained for composites prepared with either kaolin or sepiolite. However the dispersion state of sepiolite is disastrous, whereas kaolin is finely dispersed thanks to its higher OH group content, highlighting the predominant role of H-bonding interactions onto kaolin dispersion within EDBZ.

Comprehensive study on the removal of chromate from aqueous solution by synthesized kaolin supported nanoscale zero-valent iron

A removal mechanism of chromate (Cr) by synthesized kaolin supported nanoscale zero-valent iron (K-nZVI) from aqueous solution is demonstrated. Parameters which potentially influenced the functioning of K-nZVI have been investigated as well. Based on the scanning electron microscopy, Fourier transform infrared spectroscopes, X-ray crystal powder diffraction and X-ray photoelectron spectroscopy identifications, we confirm that amorphous Fe0 core/FexOy shell nZVI can be successfully loaded into the pores and cracks, and onto the surface of kaolin. Removal efficiency of Cr by K-nZVI decreased with increasing initial pH and Cr(VI) concentration, but increased while K-nZVI dosage increased. Humic acid and phosphate had similar dual impacts on chromium removal by K-nZVI, and the inhibitory effect was obvious at high concentrations in spite of their different reaction mechanisms. In contrast, high concentrations of sulfate and nitrate could advance the chromium removal. Adsorption isotherms indicate that the removal processes are endothermic. The data obtained can be better explained with Langmuir than Freundlich model. At the conditions of 318 K and optimized pH 4.0, the maximum adsorption capacity was 33.39 mg g−1 illustrating that K-nZVI was effective for the removal of total Cr. The removal mechanism is proposed to divide into four phases, including: (1) aqueous Cr(VI) ions are captured on the surface of K-nZVI; (2) the captured Cr(VI) are partly reduced to Cr(III) accompanied by Fe0 oxidizing to Fe2+; (3) part of oxidized Fe2+ continues to reduce Cr(VI); and (4) produced Cr(III), Fe2+, and Fe3+ are formed passivation layers on the K-nZVI surface which prevent further removal of chromium and result in redundant Fe0.

Experimental studies on the desorption of adsorbed sodium poly(acrylic acid) from crude kaolin particles

BackgroundThe controlled stability and fluidity of highly concentrated kaolin dispersion is a crucial problem when kaolin is used in industry due to the charge heterogeneity of its surface. To solve the common industrial problems of dispersions prepared at high solid loadings in terms of their rheological behavior, some organic and inorganic dispersing agents have to be added into the system to modify the particle surfaces. ObjectiveAdsorption and desorption behaviors of sodium poly(acrylic acid) (NaPAA) on the surface of kaolin particles were investigated to elucidate the adsorption mechanism of the PAA–kaolin dispersion system within the scope of the rheology and the colloidal stability. We also investigated the structural changes in the kaolin particles due to the extraction of Si4+ and Al3+ ions when a dispersing agent was used. MethodKaolin dispersions were prepared using NaPAA, and investigated in terms of the adsorption and desorption behaviors, the rheological and the electrokinetic properties and the extracted Al3+ and Si4+ ions from the particles. ResultsAs expected, PAA was strongly adsorbed on the positively charged alumina sites of the particles. According to the results obtained in the experiments of adsorption density, viscosity, ζ-potential and the dissolution of metal ion measurements for the adsorption/desorption, a strong and irreversible adsorption was observed between PAA and the surface of the kaolin surface, indicating the existence of unbreakable chemical bonds. This is due to the adsorption of negatively charged carboxylic acid groups (–COO−) from the PAA onto the positive alumina sites on the edges of the kaolin surface by electrostatic attraction. Due to the negative charge, no adsorption was observed on the silica surface of the particles within the working pH range of 5.3 to 8.4. ConclusionThe adsorption mechanism of PAA–kaolin interaction is attributed to chemical adsorption with the formation of chemical bonds between the charged carboxylic acid groups (–COO−) of the polymer and the alumina sites on the edges of the kaolin.

Immobilization of copper ions laden kaolin waste: influence of thermal treatment on its immobilization in cement paste

This work aims to study the influence of thermal treatment of Cu2+ laden kaolin wastes on its immobilization efficiency in cement paste. Compressive strength and toxicity characteristic leaching procedure (TCLP) of 5–20 % kaolin waste blended cement pastes were tested. X-ray diffraction (XRD) results illustrate that adsorption of Cu2+ ions modify the crystal structure of kaolinite mineral. Fourier transform infrared (FTIR) results indicate that the adsorption sites on the kaolin surface that were occupied with free water molecules have been replaced with Cu2+ ions adsorbed from aqueous solutions. The thermal treatment of kaolin waste improves fixation ratio of Cu2+ in cement pastes containing up to 20 % of thermally treated waste. This is due to: pozzolanic activity of calcined kaolin, conversion of leachable adsorbed Cu2+ ions into encapsulated unleachable phase that does not retard the hydration of cement as well as adsorption of much of leachable Cu2+ ions on surfaces of hydration products and occlusion in its lattice structure as illustrated from XRD, FTIR, thermogravimetric, scanning electron microscopy and TCLP results. The fixation ratio of Cu2+ in cement paste blended with 20 % of thermally treated kaolin waste, reaches maximum value of about 97 % compared to 82 % for cement paste blended with 20 % of untreated kaolin waste.

Competitive Adsorption of Lead and Copper by Kaolin

Due to the potential of kaolin as an adsorbent for removal of heavy metals from solution, the competitive adsorption of Lead (Pb) and Copper (Cu) by kaolin was investigated to provide further understanding on the binding behaviors and capacities of these two metals onto kaolin. The Langmuir and Freundlich isotherms were applied to further explain the competition between the metals. Three different solutions were used, each at concentrations 10, 20, 30, 45, 60 and 75mg/L: single-metal solution of Pb (Pb-Only), single-metal solution of Cu (Cu-Only), and solution of both metals at the same concentrations (Binary solution). The kaolin adsorbed Pb about twice more than Cu, both for the binary solution and for the single-metal solutions. This correlated well with predictions of maximum adsorption capacity (Q) for kaolin, where Q for Pb was about twice as much as that for Cu, both in the binary solution and in the single-metal solution. Competition from Cu in binary solution reduced Pb adsorption by 9%, while Cu rather increased by 4.1%, relative to their respective adsorptions in Pb-Only and Cu-Only, respectively. However, during competitive adsorption in the binary solution, the relative proportions of adsorbed Pb increased by 11.4% as the initial metals concentration increased from 10 – 75mg/L, while that of Cu reduced by the same proportion. This was explainable by their respective separation factors (RL), which indicated higher favorability of kaolin for Pb than for Cu. Furthermore, bonding energy (KL) of Pb unto kaolin during competition was about 2.5 times that of Cu, and was likely able to cause Pb to displace Cu from kaolin surface. This study reveals greater adsorption capacity of kaolin for Pb than for Cu, and could provide the basis for future projects/studies that would employ kaolin in Pb and Cu removal.

Magnetic modification of acid-activated kaolin: Synthesis, characterization, and adsorptive properties

Maghemite (γ-Fe2O3) nanoparticles were synthesized onto the surface of acid-activated kaolin (AAK), prepared by calcination and acid activation of a coal bearing kaolin, by immobilizing an Fe–urea complex ([Fe(NH2CONH2)6](NO3)3) and subsequent calcination. The obtained samples were characterized by X-ray diffraction (XRD), N2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS), vibrating sample magnetic measurements, and transmission electron microscopy (TEM). The results confirm the formation of ferromagnetic γ-Fe2O3 nanoparticles, approximately 18nm in size, onto the AAK surface. The obtained γ-Fe2O3/AAK nanocomposite has a high Brunauer–Emmett–Teller (BET) surface area of 99.4m2/g and possesses ferromagnetic characteristics with a maximum magnetization of 26.5emu/g. The adsorption ability of γ-Fe2O3/AAK nanocomposite was investigated using methylene blue (MB) as a typical pollutant. Owing to its high surface area, the γ-Fe2O3/AAK nanocomposite showed higher removal efficiency for MB than for parent kaolin, with a maximum adsorption capacity of 50.2mg/g. The adsorption kinetics of MB fit well with the pseudo-second-order kinetic model, and the equilibrium data can be well described by the Langmuir adsorption model.

Mechanochemical modification of kaolin surfaces for immobilization and delivery of pesticides in alginate-chitosan composite beads

The surface modification with poly(methyl hydrosiloxane) (PMHS) using a grinding method as a pesticide carrier had been successfully achieved. The characteristics of the modified kaolin were represented by Fourier transform infrared, X-Ray diffraction, BET specific surface area measurements, laser particle size analysis, transmission electron microscopy and contact angle measurement. Subsequently, immobilization of acetamiprid onto clay’s surface was carried out by means of freeze-drying technology. And the drug-loaded clays were encapsulated in alginate-chitosan composite beads by extrusion into calcium chloride solution. The composite beads showed regularly spherical shapes and uniform sizes with diameters of 1.44 ± 0.24–1.75 ± 0.19 mm. The immobilization and release of acetamiprid were carried out to examine the effect of the modified kaolin on the properties of the composite bead. The results showed that the intensive force of superfine pulverization during the grinding process was effective to increase the specific surface areas of the modified kaolin with particle size reduction. The modified kaolins as promising carrier materials had improved the drug loading rate and encapsulation efficiency from 4.15 and 42.01 % for alginate-chitosan composite beads to 6.02 and 82.95 %, which were higher than 4.33 and 54.29 % for SA-CS-kaolin composite beads, respectively. The controlled-release formulation containing the modified kaolin had shown slow and sustained release properties to promote the efficient use of organic pesticide to reduce pollution effect on the environment.

Removal of five selected pharmaceuticals by coagulation in the presence of dissolved humic acids and kaolin

Coagulation behaviour of five pharmaceuticals, i.e. acetaminophen (ACE), carbamazepine (CBZ), 17β-estradiol (E2), naproxen (NAP) and diclofenac (DCF), was investigated through jar tests in deionized water, tap water, kaolin containing water and humic acid containing water, respectively, using aluminium sulphate as a coagulant. The effects of dissolved humic acids (DHAs) and kaolin on the removal efficiency of these compounds were studied particularly. The results showed that neither ACE nor CBZ was removed effectively (less than 10%), indicating that compounds with low hydrophobicity (log Kow < 3) are difficult to be removed in coagulation process. In deionized water, DCF achieved the highest removal efficiency due to its relatively strong hydrophobicity. However, in tap water, the removal efficiencies of these pharmaceuticals were much lower than those in deionized water except E2 and CBZ. In the presence of humic acid, the removal efficiencies of acidic pharmaceuticals (NAP and DCF) were much higher than those of neutral pharmaceuticals (ACE, CBZ and E2), especially with high dosage of DHA. The maximum removal efficiencies of NAP and DCF reached 61 and 59%, respectively. In terms of E2, its removal efficiency decreased surprisingly with increasing dosage of DHA. The presence of kaolin enhanced the removal efficiencies of E2, NAP and DCF because they were more readily adsorbed onto the surface of kaolin. DHA and kaolin improved the removal of certain pharmaceuticals during coagulation process.

Synthesis, treatment, and application of a novel carbon nanostructure for removal of fluoride from aqueous solution

In this research, a new carbon nanostructure was prepared by chemical vapor deposition method on the surface of kaolin disks. Cyclohexanol and ferrocene were respectively used as carbon source and catalyst. In order to enhance the adsorption capacity of carbon nanostructure for fluoride adsorption, the disks were treated with 1M KOH at reflux conditions. The scanning electron microscopy image showed that “sword like” nanostructures with 70nm in diameter and 7030nm in length were formed on the surface of kaolin. The Infrared spectra of the treated sample revealed that the hydroxyl and carboxyl groups were produced on the surfaces. The surface functional groups were determined by the Boehm titration. Adsorption experiments indicated that removal of fluoride by the treated sample was pH dependant and under optimized condition 230.61 meq/g of F− was adsorbed, which was beyond of the capacity of the earlier studied adsorbents.

Control of inhalable particulate lead emission from incinerator using kaolin in two addition modes

Particulate lead emission control by kaolin was performed in a fluidized bed incinerator at 850–1000°C. The inhalable particulate lead was sampled after a cyclone by a low pressureimpactor. The lead capture process is proposed as three steps: 1) after capture the kaolin particle reacts with lead vapor to form PbO·Al2O3·2SiO2, then 2) lead nanoparticles from homogeneous nucleation of lead vapor conglutinate onto the melting surface of kaolin, and 3) simultaneously, fine particles containing lead conglutinate onto coarse kaolin particles. The kaolin was added in two modes: 1) mixing with solid fuel, and 2) injecting with secondary air. Compared with mode one, kaolin injection caused a much higher concentration of kaolin in the flue gas which led to the capture characteristic difference between two modes. The optimum temperature for mode one to achieve the maximum capture efficiency of submicron lead was 950°C. The optimum kaolin addition proportion for mode two to achieve the maximum capture efficiency was 3%. Overall, kaolin injection is a more effective mode to control submicron lead emission over the temperature range from 850°C to 900°C, while kaolin mixed with the fuel is a simple mode and is more effective at 950°C.

Surface modification of calcined kaolin with toluene diisocyanate based on high energy ball milling

The surface of calcined kaolin particle was modified with toluene diisocyanate (TDI) by using high energy ball milling. The prepared hybrids were characterized by FT-IR, MAS NMR, thermal analysis (TGA-DSC), static water contact angle (CA), apparent viscosity and transmission electron microscopy (TEM). FT-IR and MAS NMR spectra demonstrated that TDI molecules were chemically anchored to kaolin surface after modification. The results of thermal analysis showed that the maximum grafting ratio reached up to 446.61% when the mass ratio of TDI/kaolin was 0.5:1.0, and CA measurements revealed that the resultant hybrids exhibited strong hydrophobicity (148.82°). Apparent viscosity and TEM were employed to examine the dispersion properties of blank and modified kaolin particles in poly (dimenthylsiloxane) matrix. The results illustrated that the dispersion stability depended strongly on the grafting ratio of TDI, neither too low nor too high achieved uniform and stable dispersion, and the favorable grafting ratio was obtained when the mass ratio of TDI/kaolin was 0.2:1.0. Further modification of TDI/kaolin (mass ration of TDI/kaolin, 1.0:1.0) particles with bis(aminopropyl)-terminated-poly(dimethylsiloxane) (APS) was also investigated. TEM evidenced that the dispersion properties of the obtained TDI/APS/kaolin particles were remarkably improved in octamethyl cyclotetrasiloxane compared with the original TDI/kaolin particles.

Feasible Synthesis of TiO2 Deposited on Kaolin for Photocatalytic Applications

AbstractThe aim of the present study was to synthesize a photocatalyst on the basis of TiO2 with kaolin as the support material. Properties such as layered structure and a suitable particle size of kaolin could be beneficial in the production of a high-quality and relatively cheap photocatalyst on an industrial scale. Homogeneous hydrolysis with urea as a precipitation agent and kaolin as support material was used to obtain a kaolin surface covered with TiO2. Samples were characterized by means of X-ray powder diffraction, infrared and Raman spectroscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller surface area, and Barrett-Joyner-Halenda porosity determination. Photocatalytic activity was assessed by a Reactive Black 5 azo dye discoloration in a water suspension and by acetone decomposition on a thin layer of sample in a gas phase. The characterization confirmed that the well crystallized TiO2 was distributed effectively over the whole surface of a kaolin substrate, and photocatalytic tests revealed that the active surface layer of titania particles on kaolin performed well, suggesting that kaolin acts as a suitable support.

The effect of new ferrite/kaolin pigment on the properties of acrylonitrile–butadiene rubber composites

This work presents the preparation of rubber compounds containing new ferrite pigment for making new elastomeric magnetic composites with good properties and high savings. The pigment incorporated in this work is a new ferrite/kaolin core–shell pigment which contains a thin shell of ferrites not exceeding 10–15% of the whole pigments deposited on kaolin surface representing the core and comprises 85–90% of the pigment. These pigments have concomitant savings and are advantageous of combining the properties of both its components and overcoming their deficiencies. The evaluation of these new magnetic fillers influence on curing characteristics, physical–mechanical and magnetic properties will be estimated; these rubber ferrite composites have the advantage of easy mouldability and flexibility. Also, the effect of loading on the cure characteristics, physical–mechanical and magnetic properties of these rubber ferrite/kaolin composites will be evaluated. The study showed that, the tensile strength and elongation at break of the composites increased up to 50 parts per hundred rubber (phr) of ferrite and then decreased at higher loading whereas the hardness was increased gradually with increasing of ferrite/kaolin loadings. The magnetic tests showed that the saturation magnetization (Ms) and not the coercivity (HC) is the dominant factor which affects the energy loss in the rubber composites.

Filler-nanocellulose substrate for printed electronics: experiments and model approach to structure and conductivity

Composites made of inorganic filler particles and cellulose nanofibres can be applied as substrates for printed electronics. We have studied the structural properties of these substrates both experimentally and with particle-level modeling approach. Our model describes the skeleton structure formed by pigment particles of varied shapes and size distributions. Nanocellulose is assumed to fill voids of the structure. The model simulations predict quite well the relative changes in measured density, porosity and roughness for kaolin and precipitated calcium carbonate (PCC) pigments. Measured roughness turns out to be higher for kaolin than for PCC. Yet, the measured conductivity of printed lines on kaolin surface is higher than the conductivity on the PCC surface. The simulations reveal a more open surface pore structure for PCC than for kaolin, which leads to stronger absorption of the silver ink, and thus explains the differences in the measured conductivities.

Novel Ag/Kaolin Nanocomposite as Adsorbent for Removal of Acid Cyanine 5R from Aqueous Solution

Ag/kaolin nanocomposite was prepared by reduction of Ag+ ion with ethanol at alkaline condition on kaolin surface. Nanocomposite was characterized by FTIR, XRD, TEM, and BET methods. Results showed the Ag/kaolin composite has particle size 50 nm. The surface area was increased from kaolin to Ag/kaolin from 1.0215 to 7.409 m2 g−1, respectively. Ag/kaolin nanocomposite was used for adsorption of acid cyanine 5R (AC5R) from aqueous solution. The effect of parameters such as contact time, pH, and mass of nano composite has been investigated. The maximum percentage of adsorption of AC5R was found at pH 3 and contact time of 60 min. The higher percentage removal of AC5R by Ag/kaolin than kaolin can be attributed to catalytic activity of Ag on the surface of kaolin. The experimental data was fitted by pseudo‐second‐order kinetic model. The adsorption isotherm data could be well interpreted by Langmuir isotherm model. From the results of thermodynamic study, the adsorption process of AC5R onto Ag/kaolin nanocomposite was spontaneous and endothermic process. The process is clean and safe for purifying of water pollution.

ИЗУЧЕНИЕ ПРОЦЕССА КРИСТАЛЛООБРАЗОВАНИЯ ВОСКОВ В РАСТИТЕЛЬНЫХ МАСЛАХ ПРИ ВВЕДЕНИИ ЗАТРАВОЧНЫХ МИНЕРАЛЬНЫХ ДОБАВОК

Studying of waxes crystal formation process in the presence of kaolin is represented an actual problem. The question of working off procedure of activation of the specified mineral additive to increase its sorption ability to waxes is considered. As activating agents the sodium percarbonate and phosphoric acid solutions were used . The activated kaolin was introduced into linen and olive oils, and also an oil of a thistle in quantity of 0,2% in weight at the mass relation to waxes equal 1 : 1. It is revealed, that nucleating of wax crystals in oils can be continued during all period of crystallisation or till 6 hours. Activation of kaolin by sodium percarbonate allows to obtain larger crystals in comparison with its gradual treatment by percarbonate of sodium and phosphoric acid. The obtained result is a consequence of growth of number of the basic electron-donating centres on a surface of kaolin positively effected on the collaterally proceeding sorption of phosphorated substances of vegetable oils. Final treatment of kaolin by phosphoric acid results to increase of unit concentration of crystals in vegetable oils that testifies in favour of increase of number of the primed centres in system as the medium size of crystals drops. It is shown, that the effect of alkaline and acid-basic activation of the mineral additive can be appeared also in ratio of components of a pigment complex of vegetable oils and free aliphatic acids (≈ 20–25% is extracted).

Impact of Various Parameters Over the Adsorption of Polyvinylpyrrolidone onto Kaolin

The adsorption of water-soluble polymer, polyvinylpyrrolidone having molecular mass 9.1 ± 1.43 × 103Kg mole−1 on kaolin has been investigated. The effect of different parameters like pH, molecular mass of polymer and pre-heat treatment on the adsorption of PVP has been deliberated. The 20.7% decrease in adsorption in pH ranging from 2–10 have been found, which was an indication of the fact that with the increase in pH the kaolin surfaces sites charge amount and ultimately sign changes. Maximum adsorption was observed at pH 5.6 that was also molecular mass dependent. By increasing the pretreatment temperature, the amount of polymer adsorbed was also increased. However, above the specific temperature adsorption of PVP was decreased and attributed to decrease in specific surface area of kaolin.

Natural Rubber/ Organoclay Nanocomposite from Tea (&lt;i&gt;Camellia &lt;/i&gt;&lt;i&gt;S&lt;/i&gt;&lt;i&gt;inensis&lt;/i&gt;) Seed Oil Derivative

Sodium salt of tea seed oil (TSO-Na) was organomodified with kaolin (China clay). The organo-kaolin was characterized by determining the FTIR and XRD. Results indicated that TSO-Na was successfully intercalated onto the kaolin surface. Nanocomposite of rubber copolymer with tea seed oil organomodified kaolin was prepared by incorporating 5phr organo-kaolin. The mechanical testing of the rubber vulcanizate involved the determination of tensile and tear property. The performance characteristics showed that there was considerable improvement in the tensile strength, tear strength and elongation at break properties of the organoclay filled vulcanizate compared to the unmodified polymer. Scanning electron microscopy (SEM) studies revealed that the incorporation of 5phr organoclay has remarkable effect on the failure mechanism of the NR filled vulcanizate. This is an indication that the failure mechanism is strongly dependent on the reinforcement effect of the modified filler marked by a higher extent of rubber-filler matrix interaction. There is therefore indication that tea seed oil can be organomodified with kaolin to serve as nanofiller.

화장품에 사용되는 백색분체의 미세구조와 실리카의 특성

ABSTRACT In this study, fine structures of silica, titanium dioxide, talc and kaolin used in decorative cosmetics and the mixtureextracted from BB cream cosmetics were observed by scanning electron microscopy. Kaolin had plate like shape structuresof polygon with smooth surface and edge of kaolin had a relatively smooth appearance in comparison with talc. Also, thick-ness of each layer was estimated to about 0.1μm in the lump formed in stratum of several layers. Talc was observed bylumps shape phase of layering very thin flake. Boundary of thin flake was sharp or angular phase and thickness of flakewas approximately 600nm in diameter. When comparing the thickness of kaolin and talc, we was confirmed that kaolinwas thicker than talc. Diameter of titanium dioxide was estimated to 0.2~0.3μm and surface of particle was a soft cubicform. Silica was confirmed that variety of size from 200nm to 15μm of globular shape was measured. From the observationof inorganic pigments, silica was homogeneous dispersed in the BB cream cosmetics and among each other was filledwith relatively small size like talc, kaolin, titanium dioxide and iron oxide. In conclusion, we suggest that silica at decora-tive cosmetics were formed in cosmetic coat at the skin as the minimum thickness.Keywords : Cosmetics, Kaolin, Powder, Silica, Talc, Titanium dioxide

Novel‐modified kaolin for enhancing the mechanical and thermal properties of poly(vinyl chloride)

AbstractNovel surface‐modified kaolin with liquid‐like behavior was prepared. The characteristics of the solvent‐free kaolin fluid were evaluated by using Fourier transform infrared spectroscopy, WAXD, thermogravimetric analysis, and transmission electron microscopy. The polyvinyl chloride (PVC)/solvent‐free kaolin fluid composites were also fabricated via melt mixing. Owing to the novel surface modification, the hydrophilic kaolin surface grafted long organic chains, which made that the solvent‐free kaolin fluid could be well dispersed in PVC matrix and firmly integrated with the PVC matrix. The resulted composites exhibited better heat resistance and mechanical properties than neat PVC resins. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers