Swelling Ratio In Water Research Articles

Development of binderless fiberboard from poplar wood residue with Trametes hirsuta

The utilization of agricultural and forestry residues for the development and preparation of green binderless fiberboard (BF) is an effective way to realize high-value utilization of lignocellulose biomass resources. This study focuses on the fabrication of BF with excellent mechanical and waterproof properties, utilizing poplar wood residue (PWR) as raw material and Trametes hirsuta as a pretreatment method. During the fermentation process, lignin-degrading enzymes and biological factors, such as sugars, were produced by T. hirsuta, which activated lignin by depolymerizing lignin bonds and modifying structural functional groups, and forming new covalent bonds between poplar fibers, ultimately enhancing adhesion. Additionally, the activated lignin molecules and sugar molecules coalesce under high temperatures and pressures, forming a dense carbonization layer that bolsters the mechanical properties of the fiberboard and effectively shields it from rapid water infiltration. The bio-pretreated BF for 10 days shows a MOR and MOE of up to 36.1 Mpa and 3704.3 Mpa, respectively, which is 261% and 247.8% higher than that of the bio-untreated fiberboard, and the water swelling ratio (WSR) rate is only 5.6%. Chemical composition analysis revealed that repolymerization occurred among lignin, cellulose, and hemicellulose, especially the molecular weight of lignin changed significantly, with the Mw of lignin increasing from 312066 g/mol to 892362 g/mol, and then decreasing to 825021 g/mol. Mn increased from 277790 g/mol to 316987.5 g/mol and then decreased to 283299.5 g/mol at 21 days. Compared to other artificial fiberboards prepared through microbial pretreatment, the BF prepared by microorganisms in this study exhibited the highest mechanical properties among the poplar wood biobased panels.

A novel strategy and characteristics of PVA/citric acid cross-linked hydrophilic elastic sponge of cellulose based on medicinal herb residue

A new ultra-hydrophilic elastic sponge composite has been proposed. Medicinal herbs, commonly used in herbal medicine and subsequently discarded, are rich in natural polymer substances, making them promising candidates for various material industries. TEMPO-oxidized cellulose was extracted from medicinal herb residue, and the physicochemical properties of an ultra-hydrophilic elastic sponge, prepared through a PVA and CA impregnate cross-linking process, were investigated. The fabricated composite sponge exhibited an increase in compressive stress-strain proportional to the PVA cross-linking concentration, and its water retention capability was assessed through retention tests. Swelling tests for various solvents were conducted to evaluate the potential use of the sponge in diverse industries, revealing the highest swelling ratio in water. Pressure distribution measurements using prescale film indicated that the sponge's shock absorption capacity was enhanced by PVA cross-linking, leading to improved pressure dispersion.

Dual responsive self-healing hydrogels with wide stability and excellent mechanical strength based on aliphatic polycarbonate

The wide development of hydrogels had been used in many filed due to the high water-containing and tough three-dimensional structure, however, the poor mechanical and multi-functional properties of hydrogel can be limited in its applications deeply. Herein, the dual responsive self-healing hydrogels with tough mechanical properties were manufactured by dual-physical cross-linking based on biodegradable aliphatic polycarbonate. Choosing the soft and hard segments to design the polymeric hydrogel not only can facilitate the dual-dynamic bonding interactions but also the resilient hydrogels possess robust and controllable mechanical strength (6.51 MPa). Furthermore, the results of swelling and stability tests of the materials indicated that the swelling ability of the biodegradable hydrogels can be regulated by the hydrophilic group, and the maximal swelling ratio in water and the equilibrium water content is 66% and 40%, respectively. It is worth mentioning that the tough hydrogels embrace dual-responsive high efficiency of self-healing ability, and the self-healing time is 2 h at 50 °C or 10 h under pH = 5, suggesting that the obtained hydrogels can respond to temperature and pH value to drive the fracture interface for fast self-healing, which will offer new opportunities for stimuli-responsive materials and wound healing.

Synthesis and characterization of superabsorbent hydrogels based on carboxymethyl cellulose and agar: Agar for smart swelling and controllable delivery

The current study described a thorough analysis of the adsorption characteristics of a hydrogel that was chemically connected and built on agar and carboxymethyl cellulose (CMC). With regard to swelling %, the Agar-Agar/ECH/CMC hydrogel was created under ideal conditions. In order to achieve the highest percentage of swelling, different response parameters were changed. The structure and morphology of the hydrogels were characterized by FT-IR spectroscope, thermogravimetric analysis and scanning electron microscope. The results revealed that the CMC contributed to the enhanced size of pore, whereas Agar-Agar as a strong backbone in the hydrogel to support it for keeping its appearance. Their equilibrium swelling ratio in distilled water and different physiological fluids were evaluated, indicating the maximum swelling ratio in water reached an exciting level of 1000 as the hydrogels still keeping a steady appearance. Moreover, the hydrogels exhibited smart swelling and shrinking in NaCl or CaCl2 aqueous solution, as well as the release behavior of bovine serum albumin (BSA) that could be controlled by changing CMC content. The Agar-Agar -based hydrogels are promising for the applications in the biomaterials area.

Synthesis and Characterization of Bromelain Enzyme/Poly (Vinyl Alcohol) as Potential Bone Scaffold

3D bone scaffold is the temporary constructs substrates that enable and activate the bonding and reproduction of osteoinductive cells that lead to the creation of new usable tissues. The objectives of this research study are to synthesize and fabricate bromelain/poly (vinyl alcohol) (PVA) porous substrates by using a lyophilization technique and study the properties of the scaffold subsequently. In this study, bromelain (1, 2 and 3 wt.%) and PVA (15 wt.%) solutions were prepared, then mixed overnight to get homogeneous solution. The solutions were frozen for 24 hours before being freeze-dried under vacuum for 7 days at -80 °C. Thereafter, the porous substrates were crosslinked by using glutaraldehyde and characterized using X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). According to the XRD findings, PVA/bromelain scaffolds exhibits great degree of crystallinity at 21.11° and 41.05°. The FTIR results shows no significant effect on the absorption peak at varied concentration of bromelain in bromelain/PVA substrates. For the DSC result, the glass transition temperature was found in the range of 65 to 75 °C. For TGA curve, it was obvious that the temperatures of the weight loss regions gradually increased with the bromelain content, indicating that bromelain improves the stability of the bromelain/PVA membranes at high temperatures. Bromelain/PVA showed high porosity (>75%), and water-swelling ratio within 50 to 150 percent after 24, 48, and 72 hours immersion period. This newly developed scaffold composition may serve as a foundation for the growth of bone tissue.

Controllable Release of Povidone-Iodine from Networked Pectin@Carboxymethyl Pullulan Hydrogel.

Povidone-iodine (PI) is a common antiseptic reagent which is used for skin infections and wound healing. The control release of PI is quite important to heal the deep and intense wounds. Herein, the preparation of biodegradable pectin@carboxymethyl pullulan (Pe@CMP) hydrogel was carried out and applied for controllable release of PI. CMP was synthesized by interaction of monochloroacetic acid with pullulan at different ratios. The Pe@CMP hydrogel was then prepared by crosslinking of pectin with CMP in presence of glutaraldehyde as cross linker. After carboxymethylation, COOH contents were enlarged to be 24.2–51.2 mmol/kg and degree of substitution was 0.44–0.93. The rheological properties of Pe@CMP hydrogel were enlarged by increment of pectin ratio. Swelling ratio in water (16.0–18.0%) was higher than that of artificial sweat (11.7–13.2%). Pe@CMP hydrogel containing 20% pectin, exhibited the lowest release and 57.7% from PI was released within 360 min. The biological activity of the released PI was monitored to be highly efficient. The kinetic of release was fitted well to the first ordered reaction and Higuchi models. The mechanism of release was explained by the swelling of hydrogel. The networked structure of hydrogel was opened by swelling and PI was released from the outer pores followed by inner pores, achieving the controllable release.

The conducting fibrillar networks of a PEDOT:PSS hydrogel and an organogel prepared by the gel-film formation process

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a practical conducting polymer. The gel-film formation process produces a PEDOT:PSS organogel with a structure between a PEDOT:PSS water dispersion and a dried film. We found that this film has a high water-swelling ratio and thickens by a hitherto unreported factor of approximately 6600% as its swells to form a hydrogel. In this study, we investigated the drying behaviour of a hydrogel and an organogel with electrical properties to elucidate the internal structures of the gel responsible for the swelling and shrinkage behaviour with high expansion and contraction ratios. SEM revealed that the gel is composed of a 3D fibrillar network consisting of fibrils that are 4.6 ± 1.6 μm long and 0.63 ± 0.29 μm in diameter. This network plays a pivotal role in the conduction of electricity and swelling behaviour with high expansion ratios. The thickness of the gel decreased to 1/66 of its original value after drying on a substrate, while the total electrical resistance decreased by only 20%. The organogel exhibited the same drying behaviour as the hydrogel, which indicates that the network forms first in the organogel and is maintained in the subsequent swelling and drying processes. The electrical conductivity of the hydrogel increased from 9.0 ± 0.1 to 346.4 ± 1.2 S cm−1 under anisotropic shrinking from 3.1 ± 0.2 mm to 77.4 ± 3.3 μm. The network plays an important role as an enhanced swelling framework by providing effective pathways for the conduction of electricity.

Preparation of dextran cryogels for separation processes of binary dye and pesticide mixtures from aqueous solutions

AbstractWe present mechanically strong macroporous, squeezable dextran cryogels as a column filling material for the removal and separation of binary organic dye and pesticide mixtures from aquatic medium. Dextran cryogels were prepared from aqueous solutions of dextran of various molecular weights (MWs) in the presence of 20 to 50 mol% divinyl sulfone (DVS) as a cross‐linker at −18°C. The cryogels have interconnected irregular pores of 100 μm in sizes, and exhibit 69‐84% reversible squeezability without damaging the 3D dextran network. Their total open pore volumes (6.3‐10 mL g−1), weight swelling ratios in water (1380%‐2200%), and mechanical parameters could easily be adjusted by both DVS mol% and MW of dextran. Dextran cryogel with the highest modulus (3.8 ± 0.5 MPa), compressive stress (8 ± 2 MPa) and plateau stress (0.46 ± 0.04 MPa) was obtained at 50 mol% DVS using dextran with a MW of 15 to 25 kg·mol−1. Dextran cryogels are hydrolysable at pH = 1 and 9 but stable at 7.4 independent on both the degree of cross‐linking and MW of dextran. At below 50 mol% DVS, they are blood compatible and possess slight thrombogenic effect with blood clotting index value of 98% ± 5%. They are also capable to separate binary dye and pesticide mixtures from aqueous solutions via ionic interactions.

Reduced graphene oxide–reinforced gellan gum thermoresponsive hydrogels as a myocardial tissue engineering scaffold

Myocardial infarction is one of the most prevalent diseases around the world. Cardiac tissue engineering is a new approach to repair and revive the structure and functionality of cardiac damaged tissue. In this study, gellan gum/reduced graphene oxide composite hydrogels were fabricated, characterized, and evaluated. The hydrogels were prepared using the solvent casting method and characterized via scanning electron microscopy and Fourier-transform infrared spectroscopy. Compressive mechanical analysis, injectability as well as electrical conductivity test were run. Furthermore, water swelling and degradation analyses were conducted. MTT assay was performed using rat myoblasts (H9C2) to determine the cytotoxicity of our samples. Results showed that reduced graphene oxide fillers dispersed acceptably and enhanced the compressive modulus and electrical conductivity of gellan gum hydrogels. However, in this regard, compressive strength and ductility were not significantly boosted with reduced graphene oxide addition. The water-swelling ratio (%) rised in the presence of reduced graphene oxide, whereas the degradation rate was not significantly affected by them. Meanwhile, synthesized hydrogels showed suitable injectability. MTT assay results revealed that gellan gum hydrogels containing 1% and 2% reduced graphene oxide were not cytotoxic. According to the findings, gellan gum/2% reduced graphene oxide composite hydrogel can be a promising candidate for repairing and healing infarcted myocardial tissue.

Fabrication and Properties of a Novel Porous Material from Biopolymer and Natural Rubber for Organic Compound Absorption

Maleate poly (vinyl alcohol) (PVAM)-graft water soluble polymer with deproteinized natural rubber (DPNR) porous materials were prepared using the freeze drying technique. The effect of the water soluble polymer type (chitosan (CS) and gelatin (GT)) and the DPNR content was studied. The mechanical properties of the porous materials were improved by the addition of the DPNR. The results showed that the addition of the DPNR improved the water resistance of the porous material. Many micro-voids were formed after the PVAM was grafted with the water soluble polymers as observed under SEM, leading to changes in porosity and density. The highest number of micro-voids was found in the PVAM-graft-chitosan (sPVAM-g-CS) sample while the minimum number of microvoids was found in the maleate poly (vinyl alcohol) (sPVAM). The swelling ratio of the nPVAM significantly improved after the freeze drying process. The PVAM-graft-gelatin (sPVAM-g-GT) gave the maximum swelling ratio in water. After the DPNR was added to the sPVAM-g-GT, the pore size of the porous material significantly decreased and the size distribution became narrower. The moisture absorption, moisture content and swelling ratio of the porous material decreased after blending with the DPNR but the tear strength and rebound resilience of the porous material was enhanced. The macroporous material was able to be reused the maximum number of over 30 times as organic compound-absorbent material and it easily decomposed in nature.

Chemically clean synthesis and characterization of graphene oxide‐poly(acrylic acid–sodium styrene sulfonate) composite thermostable elastic gel encapsulating copper nanoparticles for efficient catalytic reduction of 4‐nitrophenol

ABSTRACTThe thermostable chemically blended elastic poly‐(acrylic acid–sodium‐styrene‐sulfonate–graphene oxide) super‐absorbent hydrogel was synthesized by additive‐free gamma‐radiation induced polymerization followed by crosslinking method. It showed the best swelling ratio in water due to its porous nature. The composite material adsorbed 98 mg/g Cu(II) at room temperature from the aqueous solution of Cu(II) at pH 5 by the chemi‐adsorption of Cu(II) ions at several energetically heterogeneous functional groups. The copper nanoparticles (CuNPs) of size 12 ± 8 nm had been synthesized in situ by chemical reduction of the pre‐adsorbed Cu(II) ions. The functional groups of composite hydrogel served as complexing agent and nano‐reaction sites. Avoiding any pre‐reduction induction time, the inexpensive CuNPs catalytically completely decolorized the aqueous solution of 4‐nitrophenol (4‐NP) within 60 s in the presence of NaBH4 at a promising calculated rate constant (9.0 × 10−2/s) ever reported in the literatures. It is in contrast to the commonly noticeable phenomenon for other CuNPs‐based catalysis of 4‐NP. The composite hydrogel matrix helped to retain the catalytic activity of CuNPs and simultaneously it helped in the osmotic inclusion of 4‐NP into the reaction cites. This composite hydrogel synthesized through a chemically clean method could be utilized for efficient conversion of hazardous chemical 4‐NP to industrially important chemical 4‐aminophenol. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46200.

Novel biochar-impregnated calcium alginate beads with improved water holding and nutrient retention properties

Drought conditions and nutrients loss have serious impacts on soil quality as well as crop yields in agroecosystems. New techniques are needed to carry out effective soil water and nutrient conservation and fertilizer application tools. Here, calcium alginate (CA) beads impregnated with ball-milled biochar (BMB) were investigated as a new type of water/nutrients retention agent. Both CA and Ca-alginate/ball milled biochar composite (CA-BMB) beads showed high kinetic swelling ratios in KNO3 solution and low kinetic swelling ratios in water, indicating that CA-BMB beads have the potential to retain mineral nitrogen and nutrients by ion exchange. Pseudo-second-order kinetic model well-described the swelling kinetics of both beads in KNO3 solution. Over a range of temperatures, the characteristics of dehydration suggested that impregnation with BMB improved the water holding capacity and postponed the dehydration time of Ca-alginate. The cumulative swelling and release characteristics of water, K+, and NO3− indicated that CA-BMB beads have great potential as a soil amendment to improve its nutrient retention and water holding capacity.

Preparation and properties of water-swellable natural rubber vulcanizates

Water-swellable natural rubber was prepared with natural rubber latex grafted with acrylamide. Monomer cross-linked water-swellable natural rubber and vulcanised water-swellable natural rubber were synthesised separately through grafting of acrylamide onto natural rubber latex, using formaldehyde and sulphur as monomer cross-linking agent and rubber vulcanising agent, respectively. Effects of different cross-linking modes on water-swelling properties and repeat water-swelling properties were studied. Mechanical properties were studied by dynamic mechanical analysis. The state of water in water-swellable natural rubber, cross-linked water-swellable natural rubber and vulcanised water-swellable natural rubber was studied by differential scanning calorimetry. Thermal stability of water-swellable natural rubber, cross-linked water-swellable natural rubber and vulcanised water-swellable natural rubber was studied by thermo gravimetric analysis. Microstructure of fractured surface was analysed by scanning electron microscope. The results showed that water-swelling ratio and repeat water-swelling ratio of water-swellable natural rubber were decreased with increasing amount of cross-linking agents. Storage modulus was enhanced after cross-linking treatment. Bound water absorbency and thermal stability were decreased with increasing cross-linking degree. Network structure was much more compacted after cross-linking treatment.

Mechanical, Water-Swelling, and Morphological Properties of Water-Swellable Thermoplastic Vulcanizates Based on High Density Polyethylene/Chlorinated Polyethylene/Nitrile Butadiene Rubber/Cross-Linked Sodium Polyacrylate Blends

A novel water-swellable rubber (WSR) had been prepared by dynamically vulcanized high density polyethylene (HDPE)/chlorinated polyethylene (CPE)/nitrile butadiene rubber (NBR) blends where a cross-linked poly(sodium acrylate) (CPNaAA) was used as a super water-absorbent resin. The mechanical, water-swelling and morphological properties of the WSRs were investigated. Increasing CPNaAA dosages, mechanical properties of WSRs decreased while water-swelling ratio were increased significantly; moreover, swelling ratio of WSRs with 70 phr CPNaAA was reached 956.7% at 55 h. Morphological studies showed that CPNaAA were dispersed randomly in the TPVs, and significant gaps could be found in the surface of dried WSRs.

Effect of chemical cross-linking on gelatin membrane solubility with a non-toxic and non-volatile agent: Terephthalaldehyde

In this paper, terephthalaldehyde (TPA) is proposed as non-toxic and non-volatile gelatin cross-linker. Optimal cross-linking parameters (TPA/gelatin ratio, temperature) were first determined from in situ rheological measurements on gelatin solutions and from chemical tests with 2,4,6-trinitrobenzenesulfonic acid (TNBS assays) on gelatin gel. The highest cross-linking ratio was achieved for a concentration of 0.005g TPA/g gelatin at 60°C. The impact of TPA cross-linking on gelatin membrane functional properties (water swelling ratio, water vapor sorption and mechanical properties) was measured. TPA cross-linking increased 17 times the liquid water resistance duration of gelatin films, and delayed the entry of vapor water in the polymer matrix for 7 days, indicating that TPA increased the hydrophobic character of the gelatin matrix.

Click synthesis by Diels-Alder reaction and characterisation of hydroxypropyl methylcellulose-based hydrogels

AbstractThe Diels-Alder reaction was used to fabricate hydroxypropyl methylcellulose-based hydrogels. First, hydroxypropylmethylcellulose (HPMC) was modified by a carboxyl-containing diene molecule (SFA) which was synthesised from furfurylamine and succinic anhydride. Second, dienophile groups were introduced into HPMC by the coupling reaction with N-maleoyl alanine (AMI) using N,N′-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP). Subsequently, the asprepared furan- and maleimide-modified HPMC were dissolved in water and gelation was observed at a pre-determined temperature after a period of time. The samples thus obtained were characterised by FTIR, NMR, SEM, etc. The gelation time changing with temperature, concentration of the solution, and solvent was measured. It was found that gelation time decreased with increasing temperature and concentration of the solution, and that water had a rate-accelerating effect on Diels-Alder reaction. The swelling behaviour indicates that the hydrogels have a high swelling ratio in water and the swelling ratio increases with the increasing temperature. Taking into consideration that the HPMC-based hydrogels are prepared under mild reaction conditions with an adjustable gelation time and thermal stability, the method described here has a potential application in biomaterials, especially in the areas of tissue-engineering and drug-controlled release carriers.

Swelling behaviors of superabsorbent chitin/carboxymethylcellulose hydrogels

Novel superabsorbent chitin/carboxymethylcellulose (CMC) hydrogels were successfully prepared from mixture of CMC and chitin solution dissolved in 8 wt% NaOH/4 wt% urea aqueous system at low temperature by crosslinking with epichlorohydrin. The morphology and structure of the resultant composite hydrogels were investigated by scanning electron microscope, thermogravimetry, and Fourier transform infrared spectroscopy. The results indicated that the stiff chains of chitin are as a strong backbone in the hydrogel to support the pore wall, whereas the CMC contributed to water absorption. The maximum swelling ratio in water reached an exciting level of 1300 as the hydrogels still kept an intact appearance. Moreover, the hydrogels exhibited smart swelling and shrinking behaviors in NaCl and CaCl2 aqueous solution, showing salt-responsive adsorption behaviors in different media. This work provided a “green” pathway to prepare chitin-based superabsorbent hydrogels, which would be potential for the application in the biodegradable water-absorbent material field.

Poly(ethylene glycol)-Functionalized Photocurable Silsesquioxane as an Antibiofouling Material for Nanostructure-Based Biomedical Applications

Poly(ethylene glycol)-functionalized silsesquioxane acrylate (PEG-SSQA) has been developed as antibiofouling material for nanostructure-based biomedical applications. PEG-SSQA was synthesized from the hydrolytic condensation of trimethoxysilanes with PEG and acrylate groups. From the NMR spectra, the PEG-SSQA was observed to be a mixture of random, ladder, and cage structures. The cured PEG-SSQA exhibits hydrophilicity (water contact angle: 26.6–34.7°), low swelling ratios in water (<1.8 wt %) and organic solvents (< 3 wt %), a high UV transparency (>90% at 365 nm), a high Young's modulus (ca. 1 GPa), and low shrinkage (< 4.2% in height). PEG-SSQA possessed the ability to form sub-25 nm features. In addition, the cured PEG-SSQA films with long-term stability under chemical and biological stress showed strong resistance to the nonspecific adsorption of proteins. These characteristics may offer a new strategy for the development of a number of biomedical applications, such as nanobiodevices, nanobiosensors and labs-on-a-chip.

Water-Swellable Thermoplastic Vulcanizates Based on Ethylene-vinyl Acetate Copolymer/Cross-linked Sodium Polyacrylate/Chlorinated Polyethylene

A novel water-swellable rubber (WSR) was prepared by dynamically vulcanizing ethylene-vinyl acetate copolymer (EVA)/chlorinated polyethylene (CPE) blends where the cross-linked poly (sodium acrylate) (CPNaAA) was used as a super water-absorbent resin and dispersed in the CPE rubber. Experimental results showed that the mechanical properties of TPVs decreased while the water-swelling ratio increased significantly with increasing of CPNaAA dosages, the swelling ratio of 60 phr CPNaAA TPVs reaching 746.1% at 93 h. Morphological study showed that the CPNaAA particles were dispersed randomly in the TPVs; Some significant gaps and large cavities could be found in the surface of dried TPVs.

Water-swellable thermoplastic vulcanizates based on ethylene–vinyl acetate copolymer/chlorinated polyethylene/cross-linked sodium polyacrylate/nitrile butadiene rubber blends

A novel water-swellable rubber (WSR) has been prepared by dynamically vulcanized ethylene–vinyl acetate copolymer (EVA)/chlorinated polyethylene (CPE)/nitrile butadiene rubber (NBR) blends where the cross-linked poly(sodium acrylate) (CPNaAA) was used as a super water-absorbent resin and dispersed in the NBR rubber. The mechanical properties, water-swelling behavior, weight loss and crystallization behavior of the prepared WSRs were investigated systemically. When the CPNaAA content was 20 phr above, the increase in CPNaAA dosage contributed to the decrease in mechanical properties. However, the WSRs showed strong water-swelling behaviors and the water-swelling ratio of WSRs with 50 phr CPNaAA was 669.3% at 120 h. The WSRs with 60 phr CPNaAA showed high water-swelling rate and achieved the equilibrium swelling at about 566.3% in 23 h. The secondary and third water-swelling behaviors of WSRs showed significantly rapid equilibrium swelling and remarkable decrease in weight loss. X-ray diffraction results revealed the increase in CPNaAA content would result in the reduction of crystalline structure content in EVA. Morphological study of etched surface showed that the CPNaAA particles were dispersed evenly in the WSRs and coated with cross-linked NBR rubber; moreover, field-emission scanning electron microscopic graphs showed the crystalline structure of EVA and clusters of flakes were dispersed on the etched surface of WSRs.