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Effect of magnetic and thermal properties of iron oxide nanoparticles(IONs) in nitrile butadiene rubber (NBR) latex

Hun Tiar Ong, Nurhidayatullaili Muhd Julkapli, Sharifah Bee Abd Hamid n,O. Boondamnoen, Mun Foong TaiQ1

Nanotechnology & Catalysis Research Centre (NANOCAT), 3rd Floor, Block A, Institute of Postgraduate Studies (IPS), University of Malaya, 50603 KualaLumpur, Malaysia

a r t i c l e i n f o

Article history:Received 16 April 2015Received in revised form30 June 2015Accepted 12 July 2015

Keywords:Iron oxide nanoparticlesNitrile butadiene compositemagnetic detectabilitymagnetizationthermal stability

a b s t r a c t

Nitrile butadiene rubber (NBR) gloves are one of the most important personal protective equipments butthey are possible to tear off and contaminate food or pharmaceutical and healthcare products duringmanufacturing and packaging process. High tendency of torn glove remaining in food or products due towhite or light flesh-coloured glove is not easy to be detected by naked eyes. In this paper, iron oxidenanoparticles (IONs) selected as additive for NBR to improve its detectability by mean of magneticproperties. IONs synthesized via precipitation method and compounded with NBR latex before casting onpetri dish. The properties of IONs were investigated by X-ray Diffractometry (XRD), Transmission Elec-tron Microscope (TEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). MeanwhileNBR/IONs composites were studied by Thermogravimetry Analysis (TGA), Differential Scanning Calori-metry (DSC) and Vibrating Sample Magnetometer (VSM). It observed that, synthesized IONs shows of25.28 nm crystallite with 25.86 nm semipherical (changed as) shape. Meanwhile, Magnetite and ma-ghemite phase are found in range of 670 cm�1 and 700 cm�1 respectively, which it contributes mag-netization saturation of 73.96 emu/g at 10,000 G by VSM. Thermal stability and magnetic properties wereincreased with incorporating IONs into NBR latex up to 20 phr. NBR/IONs 5 phr has the optimum thermalstability, lowest glass transition temperature (�14.83 °C) and acceptable range of magnetization sa-turation (3.83 emu/g at 10,000 G) to form NBR gloves with magnetic detectability.

& 2015 Published by Elsevier B.V.

1. Introduction

Nitrile glove was highly demanded by manufacturing andpackaging line employees in food processing, pharmaceuticals andmedical industries [1]. These industries are intensively concernabout hygiene and quality of their products. During manufacturingor packaging process, torn gloves might unconsciously drop intothe products, leading to contamination. Food contamination is aserious issue which it probably leads to food poisoning in certainextend. Therefore, nitrile glove used in this industry are usuallywhite, light flesh or light blue colour. Even though precaution hasbeen taken, food contamination will remain unsolved, as visualdetection is not reliable. In late 1960s, large amount of bariumferrite particles was combined with NBR and extruded into solidshapes for flexible magnets application [2]. It initiated the idea ofincorporating magnetic properties materials into NBR. For in-stance, magnetic properties of nitrile butadiene rubber (NBR) were

induced by incorporating yttrium, iron and strontium ferrite withNBR [3]. Besides that, another invention of latex with magneticdetectability was designed by incorporating chromium oxide withNBR latex [4].

Apart from improving magnetic properties of NBR latex, NBR/IONs composite might enhance thermal properties due to thenature of IONs with high thermal properties. For example, somestudies have been carried out such as incorporating nanoclay withNBR to improve thermal properties [5]. This type of composite wassignificantly improving oil and heat resistance of NBR polymer. Inelectrochemical devices, polymer electrolytes required certain le-vel of thermal stability and polymer electrolytes was formed byNBR as well as ionic liquid [6]. Investigation on magnetic andthermal properties of NBR/IONs composite has not been widelyattended in the researches.

Therefore in this study, IONs consist of magnetite and maghe-mite phase were synthesized and introduced in NBR latex to in-duce magnetic properties and further enhance its magnetic andthermal stability. Different IONs loading into NBR latex has beenstudied to optimize the magnetic and thermal properties of NBR/IONs composite. In the work, the attempt has been made to study

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Contents lists available at ScienceDirect

journal homepage: www.elsevier.com/locate/jmmm

Journal of Magnetism and Magnetic Materials

http://dx.doi.org/10.1016/j.jmmm.2015.07.0280304-8853/& 2015 Published by Elsevier B.V.

n Corresponding author.E-mail address: [email protected] (S.B.A. Hamid).

Please cite this article as: H.T. Ong, et al., Journal of Magnetism and Magnetic Materials (2015), http://dx.doi.org/10.1016/j.jmmm.2015.07.028i

Journal of Magnetism and Magnetic Materials ∎ (∎∎∎∎) ∎∎∎–∎∎∎

www.elsevier.com/locate/jmmm

http://dx.doi.org/10.1016/j.jmmm.2015.07.028



mailto:[email protected]






the IONs loading on thermal stability and magnetic properties ofproduced composite by Differential Scanning Calorimetry (DSC),Thermogravimetry Analysis (TGA) and Vibrating Sample Magnet-ometer (VSM), respectively. In fact, evaluation of thermal stabilityfor NBR composite contributed some relevant information re-garding to glass transition, crystallization and melting tempera-ture of NBR composite, which could be an interesting subject forlaboratorial and industrial applications.

2. Materials and methodology

Iron (II) sulphate heptahydrate (FeSO4 �7H2O) and Ammoniumhydroxide (NH4OH, 25%) were used as iron salt and base precursor,respectively. Ethanol 95% AR grade and deionised water (DI water)were used to wash samples. FeSO4 �7H2O, NH4OH and ethanolwere purchased from Merck Millipore. IONs were synthesizedbefore compounding with NBR latex. NBR latex (acrylonitrilecontent: 24–26%) was supplied by Synthomer Sdn Bhd meanwhileother compounding ingredients (ZnO, sulphur and accelerator DMwere supplied by Bayer, Germany. Stearic acid on the other handwas supplied by Sigma-Aldrich.

2.1. Synthesis of IONs

FeSO4 �7H2O was mixed with 50 ml water to form 0.2 M ironsalt precursor while NH4OH, 25% was added to 50 ml water toform 6.68 M of base precursor. The mixture was stirred for 15 minand ultrasonicated for 10 min to produce a well dissolved FeSO4.Consequently, the dissolved mixture was poured once into baseprecursor, subsequently stirred for 2 h. Final solution was washedwith DI water for 5 times and decanted by using neo magnet. Theproduced precipitation was dried at room temperature for char-acterizations. For compounding purpose, the final solution waswashed once with DI water and kept in slurry form. Slurry wasmaintained at pH 9–10 with approximately 25% of dry IONs in it.

2.2. Preparation of NBR/IONs composite film

Latex compound was prepared by adding all compounding in-gredients as shown in Table 1. NBR latex was filtered and stirredwith 50 rpm for 30 min at room temperature. ZnO, acceleratorDM, stearic acid and sulphur were added into NBR latex by stirringat the same speed for an hour to ensure homogeneous mixing ofthe compound. Similarly, IONs were added and continuously stir-red for another hour. After compounding, stirring speed was re-duced to 30 rpm and latex compound was left for overnight. 2 g ofcompounded latex was casted on a petri dish (area: 38.48 cm2) inorder to obtain a thin layer of latex. After that, it was cured in theoven at 80 °C for 45 min and finally NBR/IONs composite film wasformed. The obtained NBR/IONs composites film was assigned as

according to the composition of IONs: 0 NBR/IONs, 5 NBR/IONs, 10NBR/IONs, 15 NBR/IONs and 20 NBR/IONs.

2.3. Characterization of IONs

Crystallite phase of IONs was determined by X-ray Diffractionusing Cu Kα radiation (XRD, λ¼ 1.5406 Å, Bruker axs D8 Advancediffractometer). Step size was set at 0.02° with 0.02°/s scanningrate in between 2° and 80° diffraction angle (2θ). From the result,it can be determined the crystalline size of magnetite nanoparticleby using Scherrer equation. Besides, Raman Spectroscopy (Re-nishaw in Via Reflux) with high performance CCD camera andLEILA microscope was used in this study. Scattered radiation wascollected by focusing laser beam via �50 objective and the laserspot on sample was approximately 0.836 mm with 514 nm excita-tion. Argon gas laser (514 nm) was selected in our paper as1800 mm�1 spectral due to its resolution is sufficient to plot agood spectra. HRTEM analysis was performed by JEM-2100F in-strument with accelerating voltage 200 kV. Samples were pre-pared by dropping dispersed IONs on copper grids of 300 mesh.The measurement of lattice-fringe spacing was carried out byusing Image-J. Besides, 50 IONs particles were measured to de-termine particle size distribution. Vibrating Sample Magnetometer(Lakeshore – VSM 7407) was used to study magnetic properties ofIONs. Roughly 0.03 g of IONs was prepared and magnetic fieldfrom �10,000 G to 10,000 G was applied to identify magnetiza-tion saturation.

2.4. Characterization of NBR/IONs composite film

Differential Scanning Calorimetry (Mettler Toledo DSC 827e)was performed under nitrogen atmosphere at 10 °C/min heatingrate in temperature range of �70 °C and 500 °C to determine thephysical phase transitions as well as specific enthalpies of NBR/IONs composite film. Thermal stability of NBR/IONs composite filmwas determined by Thermogravimetric analysis (Mettler Toledo,TGA/SDTA-851e). Heating rate and temperature range duringthermogravimetric analysis was 10 °C/min and 25–800 °C, re-spectively under nitrogen environment. The magnetic propertiesof NBR/IONs composites were evaluated by Vibrating SampleMagnetometer with the small piece of NBR/IONs composite filmcutting. The sample was pasted at sample holder before starting toramp up magnetic field from �10,000 G to 10,000 G.

3. Results and discussion

3.1. Properties of IONs

Fig. 1 demonstrates X-ray Diffraction patterns of IONs. XRDpatterns confirmed that magnetite and maghemite were formed atall the conditions applied. In fact, they are further confirmed bytheir composition of Fe3O4 and γ-Fe2O3 nanocrystal peaks collatedwell with JCPDS card (19-0629) and JCPDS card (39-1346), re-spectively. In general, unstable Fe2þ cations in inverse-spinelmagnetite octahedral site are easily be oxidised into Fe3þ . This isapplied for this synthesis method since open environment con-ditions have been used (room temperature and humidity) [8]. Arange of partially oxidized magnetite to fully oxidized maghemitewas formed. In consequence, Scherrer equation was implementedto calculate crystallite size of IONs at corresponding peak of (220),(311), (400), (422), (511) and (440) which is illustrated in Table 2.IONs with 10.6 nm crystallite size were determined at plane (311)and it was the highest peak shown in Fig. 1. Average crystallitesize, 25.28 nm was large apt to greater magnetic properties ofIONs. Demortiere et al. [7] reported that crystallite size was

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Table 1Formulation of NBR latex compound.

Materials Amount (phra)

NBR 100Sodium dodecylbenzene sulphonate (SDBS) 0.5Sulphur 1.5ZnO 5Stearic acid 1Accelerator DMb 1.5IONs Variable (0, 5, 10, 15, 20)Wax 2.1

a Parts per hundred rubber parts in weight.b Dibenz thiazyl disulphide.

H.T. Ong et al. / Journal of Magnetism and Magnetic Materials ∎ (∎∎∎∎) ∎∎∎–∎∎∎2






increased from 3.1 nm to 12.8 nm by X-ray Diffractometer (XRD)were increasing the magnetization saturation at �268 °C from 29to 77 emu/g. This is supported by Kim et al., who mentioned thatparticle size is linearly increased with crystallite size [8]. There-fore, it can be concluded that crystallite size (25.28 nm) con-tributed well to magnetization saturation (to show the data early,73.96 emu/g) at room temperature.

Depicted in Fig. 2 is a Raman spectrum of IONs where mag-netite and maghemite are shown in different peaks. Li et al. [9]stated that magnetite is poor Raman scatterer because low laserpower is needed (less than 0.35) to prevent phase transformation

of magnetite to maghemite or further transform to geotite andhematitie. Thus, in this study 0.2 mV is selected in the Ramananalysis. However, it observed that longer exposure of laser irra-diation was also contributed to the transformation of magnetite.According to Slavov [10], magnetite has strong peak at 668 cm�1,maghemite has strong peaks at 350 cm�1, 500 cm�1 and700 cm�1 while haematite has strong peaks at 225 cm�1,299 cm�1 and 412 cm�1. From Fig. 2, there is no obvious peak ofhaematite recorded. This can be explained by oxidation rate ofFe2þ which is depending on the presence of inorganic ligands.Oxidation rate is decreasing from perchloride, fluoride, nitrate,chloride, carbonate, sulphate, silicate until phosphate [11]. It isexpected that, slow oxidation rate might prevent further trans-formation of maghemite to haematite. Therefore, in our study,magnetite and maghemite are found in IONs. Most of the peaksafter 1100 cm�1 are not meant for iron oxide phase identification[12].

HRTEM analysis of IONs was carried out with 15,000 timesmagnification and 120,000 times magnification and shown inFig. 3a and c, respectively. In general, the IONs particles demon-strated in semispherical shape with average size of 22.62 nm(Fig. 3b). The most particle size 20–25 nm and it close to averagecrystallite size 25.28 nm (Table 2). Particle size and crystallite sizeare correlated to each other, thus influencing the magnetic prop-erties of IONs [8]. Agglomerated IONs can be seen clearly in Fig. 3aand c. This is due to the nature of IONs which consist of van derWaals forces and magnetic dipolar forces among the particles. vander Waals forces result in short range isotropic attraction whilstmagnetic dipolar forces induce anisotropic interactions betweenthe IONs particles [13]. It expected that, surface modification andcoating of IONs can be carried out to minimize the agglomerationwhile improving compatibility of IONs to NBR latex. Fig. 3d showsa typical HRTEM image of IONs with 25.06 nm of size. This na-nosize IONs was found in the sample with interplanar distances ofd1¼0.305 nm, d2¼0.315 nm and d3¼0.316 nm that are very closeto planes (220) as shown in Table 2. Thus, it further confirms thatFe3O4 and γ-Fe2O3 are existed in the sample [14].

Fig. 4 shows ferromagnetic hysteresis loop of IONs. In general,Ms of bulk magnetite is recorded at 92 emu/g. However, the pro-duced IONs have lower Ms which is 73.96 emu/g at 10,000 G [15].Magnetic properties of IONs are relatively strong due to its largediameter of crystallite size. IONs indicate small coercivity at760 G and remanence at 77 emu/g. According to Zhang et al.[16], zero remanence and coercivity represent the super-paramagnetic properties of the material. Depicted in Fig. 4, itconfirmed that, IONs are not superparamagnetic because magne-tization curve was not intersected at zero point. Super-paramagnetic IONs are usually smaller than 20 nm [17]. It is ob-viously observed as well the present of hysteresis loop. Hysteresisloop was brought by the domains of IONs, which do not return totheir original orientation once applied field was reduced. Max-imum estimated single-domain size of magnetite and maghemiteare 128 nm and 166 nm [18]. IONs synthesized were single-do-main and dependant on particle size. Therefore, coercivity wasdecreased attributed to small particle size of IONs. Besides, wenotice that IONs achieved 53 emu/g at 1000 G applied magneticfields. This property is useful as its sensitivity allow magnetic NBRlatex easily to be detected by magnetic detector.

3.2. Thermal properties of NBR and NBR/IONs composites

Fig. 5 illustrates on effect of IONs concentration (0–20 phr)towards the thermal stability of NBR. Two obvious degradationslopes exist in temperature between 180 °C and 320 °C as well as360 °C and 500 °C. Besides, degradation rate from 180 min to320 min and 360 min to 500 min and residue of NBR and NBR/

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Fig. 1. XRD pattern of IONs.

Table 2XRD data for IONs at different planes.

a b c d e f Average

Degree (2θ) 30.2 35.5 43.2 53.7 57.1 62.7 –

Crystalline plane (hlk) (220) (311) (400) (422) (511) (440) –

Theory value of JCPDScard (19-0629)

0.297 0.253 0.210 0.171 0.162 0.148 –

Theory value of JCPDScard (39-1346)

0.295 0.252 0.209 0.170 0.161 0.148 –

Crystallite size of IONs(nm)

17.4 10.6 27.1 18.9 38.3 39.4 25.28

Fig. 2. Raman spectra of IONs.

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Fig. 3. (a) TEM image of IONs with 15,000� magnification. (b) Histogram of particle size distribution with average size 22.62 nm. (c) TEM image of IONs with 120,000�magnification. (d) Interplanar distance corresponded to IONs (25.06 nm).

Fig. 4. Magnetization curve of IONs.Fig. 5. Thermal properties of NBR and NBR/IONs composites.







IONs are tabulated in Table 3. Temperature at different weight lossof NBR and NBR/IONs are summarized in Table 4. In general, allproduced sample recorded the mass loss up to 19.141% in thetemperature range 180–320 °C, attributed to evaporation of thesurfactant, stearic acid and wax. Similarly, degradation rate from180 min to 320 min was decreased once IONs was incorporatedinto NBR latex. This was due to the significant reduction of massloss after addition of IONs into NBR, which brought by the presentof carboxylic groups of stearic acid. In general, present of car-boxylic acid assisted in formation of covalent binding to surface of

IONs [18]. Meanwhile mass loss and degradation at this tem-perature and time range respectively were increased with in-creasing IONs loading from 5 to 20 phr. It shows that increasingIONs more than 5 phr has given some minor reduction on thermalstability of NBR/IONs composite.

As the temperature went up to 500 °C, second degradation isoccurred which attributed to polymer matrix pyrolysis [19].However, mass loss and degradation rate of NBR/IONs compositeswere decreased from 75.466% to 50.61% and 0.539%/min to0.3615%/min respectively (Fig. 6a–d) with increasing IONs loadingfrom 0 to 5 phr. Similarly NBR/IONs composites were proven towithstand at higher temperature (Table 4) than NBR at 10%, 30%and 50% weight loss. It can be concluded that thermal stability ofNBR/IONs composite was improved, contributed by high thermalstability of IONs to resist NBR chain mobility [20]. Temperature at10% and 30% weight loss of NBR/IONs 5 phr was higher compare toothers NBR/IONs composites. Meanwhile, its temperature at 50%weight loss was slightly lower than NBR/IONs 20 phr. It can beexplained that 5 phr loading of IONs into NBR latex had optimumthermal stability. Nevertheless, presence of residue at 500–800 °Cas shown in Table 3 is due to presence of IONs. Percentage of re-sidue was increased with incorporation of IONs into NBR was in-creased. IONs have higher degradation temperature, contributingto higher residue percentage compare to compounded NBR. NBR/IONs 10 phr was noticed to have lower residue percentage thanNBR/IONs 5 phr (Fig. 6e). It was recorded as well that, greateramount of residue on NBR/IONs 5 phr. This was due to highthermal stability even though temperature was increased to800 °C. Indeed, NBR/IONs 5 phr was good IONs loading as it pro-vided good stability of product as well as lower cost NBR/IONscomposite. It can be claimed that IONs with 5 phr loading hasbetter IONs distribution in NBR latex which it enables heat todistribute evenly within the whole composite composition. Thecomposites with greater IONs loading tends to agglomerate beforethe composite was formed, contributing to heat concentration inthese composites [21].

Fig. 7 provides thermograms of NBR and NBR/IONs composites.Glass transition temperature (Tg), crystallization temperature (Tc)and specific enthalpy of NBR and NBR/IONs composites are tabu-lated in Table 5. NBR has slightly higher Tg (�12.19 °C) comparedto NBR/IONs composites due to addition of IONs into NBR latex.

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Table 3Mass loss, degradation rate and residue of NBR and NBR/IONs composites.

Sample Mass loss at tempera-ture (%)

Degradation rate at time(%/min)

Residue (%)

180–320 °C

360–500 °C

18–32 min 36–50 min 500–800 °C

NBR 19.141 75.466 0.1367 0.5390 5.392NBR/IONs5 phr

6.195 73.317 0.0443 0.5237 20.482

NBR/IONs10 phr

10.023 68.017 0.0716 0.4858 16.021

NBR/IONs15 phr

10.622 57.525 0.0759 0.4109 27.689

NBR/IONs20 phr

11.972 50.610 0.0855 0.3615 32.156

Table 4Temperature at different weight loss of NBR and NBR/IONs composites.

Sample Temperature at 10%mass loss (°C)

Temperature at 30%mass loss (°C)

Temperature at 50%mass loss (°C)

NBR 260 405 442NBR/IONs5 phr

373 430 449

NBR/IONs10 phr

320 422 446

NBR/IONs15 phr

308 423 449

NBR/IONs20 phr

295 422 452

Fig. 6. Mass loss at temperature (a) 180–320 °C and (b) 360–500 °C, degradation rate at time (c) 180–320 min and (d) 360–500 min as well as (e) residue left with differentIONs loading.







There was not a significant different Tg (less than 2 °C) in betweenNBR and NBR/IONs composites was recorded. In fact, lower Tg hasprivilege in remaining the rubbery state of NBR/IONs compositesat lower temperature. IONs prevent phase changes of NBR matrixby reacting with polymeric chain and widen the rubbery range ofNBR/IONs composites. This phenomenon is similar with the onesrecorded for the NBR composites incorporated with multi-walledcarbon nanotube filler [19]. NBR/IONs 5 phr indicates the lowest Tgand it enabled the composite to operate in lower temperaturecompare to NBR. Meanwhile higher IONs loading (10 phr) in-creased Tg up to �13.23 °C attributed to nature of IONs tended toagglomerate due to the van de Waals forces between its nanopa-ticles. This in turn, resulted in micro-sized rather than nano-sizedIONs particles. Agglomerated IONs reduced free volume of NBRand further restricted movement of polymer segment [22]. Spe-cific enthalpy of Tg was diminished from 1.43 J/g to 0.72 J/g whenIONs loading was increased from 0 phr to 20 phr. This phenom-enon was caused by phonon scattering reduction whereby IONsconstrain the NBR segment mobility by entrapping phononswithin IONs [20]. Fig. 7 reveals that crystallization temperature ofNBR and NBR/ONs composites were at 365 °C. Heating was in-duced orientation in amorphous state of NBR in order to alignparallel to each polymer chain. However, latent heat of crystal-lization was reduced from 808.33 to 404.67 J/g with increasingIONs loading from 0 to 20 phr. Incorporating IONs into NBR tendedto hinder the ordering arrangement of polymer chains due tosome agglomerate IONs at this temperature [23]. This can furtherexplain that higher IONs loading reduced latent heat crystal-lization attributed to higher tendency of IONs agglomeration atcrystallization temperature.

3.3. Magnetic properties of NBR and NBR/IONs composites

Magnetization curve of NBR and and NBR/IONs composites aswell as their magnetization saturation, coercivity and remanenceare presented in Fig. 8 and Table 6, respectively. Coercivity of NBRwas increased or reduced from 0 to 760 G after incorporatingIONs into NBR. It was noticed that coercivity of NBR/IONs com-posite was remain constant even though IONs loading was in-creased from 5 to 20 phr. It proved that increasing IONs loadinggave insignificant effect on the coercivity and very small intensityof magnetic field (760 G) was required to reduce magnetic mo-ment to zero. Besides that, coercivity of NBR/IONs composites hadexactly similar coercivity as pure IONs as shown in Fig. 4. Re-manence on the other hand was increased or reduced from 0 to70.71 emu/g as IONs increased from 0 to 20 phr. Therefore,greater magnetic moment left behind after removing the externalmagnetic field can be observed as IONs loading was increased. Itmight cause NBR/IONs to stick to each other if too high remanencepresent in the composite. However, huge drop of remanence from77 to 70.71 emu/g was noticed when pure IONs was in-corporated into NBR with 20 phr. Hence, NBR/IONs composite canbe classified as soft magnetic composite materials [24]. Magneti-zation saturation was increased or reduced from 0 to 713.4 emu/gas IONs loading was increased from 0 to 20 phr. High loading ofIONs improved magnetic properties of NBR/IONs composite, thusimproving detectability of this composite. Magnetization satura-tion of IONs (73.96 emu/g) was reduced to 13.40 emu/g for NBR/IONs 20 phr attributed to shielding effect of NBR towards IONs andlower concentration of IONs in NBR/IONs composite. According toMarian and Marcin [25], IONs are well align in NBR matrix and ithas larger magnetic susceptibility. Therefore, it is suitable to

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Fig. 7. DSC thermograms of NBR and NBR/IONs composites and inset shows thecorresponding Tg curves.

Table 5Glass transition, crystallization and specific enthalpy of NBR and NBR/IONscomposites.

Tg (°C) Specific enthalpyof Tg (J/g)

Tc (°C) Latent heat of crystal-lization (J/g)

NBR �12.19 1.43 365 808.33NBR/IONs5 phr

�14.83 1.32 365 682.19

NBR/IONs10 phr

�13.23 1.00 365 566.41

NBR/IONs15 phr

�14.02 0.80 365 514.74

NBR/IONs20 phr

�14.39 0.72 365 404.67

Fig. 8. Magnetization curve of NBR and NBR/IONs composites.

Table 6Magnetic properties of NBR and NBR/IONs composites.

Coercivity, Hc

(G)Remanence, Mr

(emu/g)Magnetization satura-tion, Ms (emu/g)

NBR 0 0 0NBR/IONs5 phr

760 70.22 73.83

NBR/IONs10 phr

760 70.44 77.80

NBR/IONs15 phr

760 70.60 710.00

NBR/IONs20 phr

760 70.71 713.40







incorporate into NBR latex as proven by NBR/IONs 5 phr that isable to achieve 3.83 emu/g. In fact, in our study, a Safeline modelS35 metal-particle detector can detect magnetic moment as low as0.80 emu/g and NBR/IONs 5 phr exceeded the minimum magneticmoment sensor of the detector [3].

4. Conclusion

Magnetic IONs with particle and crystallite size of 25.86 nmand 25.28 nm respectively were successfully synthesized by pre-cipitation method as a magnetic additive for NBR gloves. Magne-tite and maghemite phase were existed, leading to higher mag-netization saturation. Therefore, high magnetization saturation(73.96 emu/g) of IONs was favoured to improve magnetic prop-erties of NBB latex with 5 phr loading of IONs. Besides that, IONswas found to improve thermal stability of NBR/IONs composites. Tgof NBR/IONs composites were slightly reduced, leading to betterflexibility of composites at low temperature. Magnetization sa-turation of NBR latex was increased with increasing IONs loading.In this study, NBR/IONs 5 phr has the optimum thermal stabilitylowest glass transition temperature and acceptable range ofmagnetization saturation to form magnetic detectability films.

Acknowledgements

This work was supported by Hartalega Sdn Bhd under projectof NanomagnQ2 etic as an additive for nitrile butadiene rubber. Theauthor also wants tQ3 o acknowledge Fundamental Research GrantScheme (FRGS: FP049-2013B) by Ministry of High Education(MOE), Malaysia.

References

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