Nondestructive testing of defects in adhesive joints

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composites containing nano additives as well as conducting PANI should improve tremendously the barrier properties of coatings as well as self healing effect giving large advantage in anticorrosion behaviour. Hence, the present studies were carried out on the preparation of nano TiO2-PANI hybrid coating formulations using polyvinyl butyral (PVB) as the matrix and investigating their suitability for anticorrosive coatings. 2. Experimental: 2.1 Material Aniline (ANI) ( AR, Spectrochem Pvt. Ltd. India ) was purified by distillation, 38% hydrochloric acid ( AR,Ranbaxy), TiO2 particles, ammonium peroxodisulphate ( APS, AR, Spectrochem Pvt. Ltd, India) and methanol (E Merk ) were used as such. Poly vinyl butyral (PVB) with M.W. 60,000 was obtained as granules from ABC Chemicals Exporter, Mumbai, India. 2.2 Preparation of PANI-TiO2 composites of different PANI-TiO2 ratio To prepare PANI-TiO2 composites of different ratios, the following steps were followed. 0, 0.1, 0.2, 0.3 and 0.5 g of TiO2 nanoparticles (prepared according to procedure reported earlier ) were added into a mixture of 1ml aniline and 90ml 1N HCl in a set of reaction vessels. The mixtures were stirred with magnetic stirrers in ice water baths for one hour to get a uniform suspension of TiO2. To these mixtures, 100 ml pre-cooled 1N HCl solutions containing 2.5 g APS were added drop wise. The resulting mixtures were allowed to react in ice bath for about four hours. From these reactions we get pure PANI and TiO2-PANI composites with compositions given in Table- 1A. The products were washed with distilled water for several times and at last washed with methanol to remove low molecular weight oligomers along with other impurities. Then all samples were dried in an oven for 12 hours. These samples were characterized by UV, IR, XRD, SEM and TEM in the usual manner. 2.3 Preparation of PANI-TiO2 dispersion formulations for coating PVB (2g) was dissolved in methanol (20 ml) with continuous stirring for 6hr and then in a sonicator for few hours. The 10 wt % of PANI-TiO2 powder having different compositions was crushed and slurry was made with small quantity of methanol. The slurry was added and mixed in the PVB solution and subjected to sonication for 24 Hrs. This yielded a uniform dispersion of PANI-TiO2 in the PVB solution with no settling. The stainless steel coupons (50mmx 10mmx 1mm) with rounded corners and edges were polished by C- 800 emery paper, washed with acetone and dried. The substrates were dip coated for 30 sec in PVB/PANI-TiO2 dispersion and dried at room temperature for 30 min followed by baking in air circulating oven at 50 0 C for 4 hr. The samples were cooled and then subjected for measurement of corrosion inhibition properties.. 2.4 Testing of corrosion resistance properties Tafel plot and impedance measurements were carried out in 3.5 % NaCl solution as electrolyte. All measurements were performed on computerized electrochemical analyzer (supplied by CH instruments, USA). Stainless steel plates coated with the PANI-TiO2 composites were used as working electrode while Pt and SCE were the counter and reference electrodes respectively. The voltammograms were measured between +1 to –1 V at a scan rate of 50 mV/s. Tafel plots was recorded at a scan rate of 10 mV/s. After initial measurements all the coupons were immersed in an external bath with hot 3.5 % NaCl solution (65 o C) for a period of 4 hrs so that accelerated testing could be carried out. The coupons were then again subjected to electrochemical measurements at an interval of 4 hours as described above [10, 19]. Micrographs of corroded samples were recorded on polarized optical microscope fitted with digital camera (model Leica Stereoscan 440, UK).
3. Results and Discussion : The wide angle XRD of the PANI-nanoTiO2 powders is depicted in Figure-1 which indicates the typical PANI peaks with broad amorphous band for the samples with no TiO2 and the characteristic reflections of anatase (JCPDS-21-1272) for the composite. The crystallite size determined from the FWHM of main 101 reflection of TiO2 is 75 nm. Intensity 2500 2000 1500 1000 500 A B 20 40 60 Diffraction angle (2θ ) Figure:1. X-ray diffraction of (A) PANI and (B) PANI with nano-TiO2 There is an increase in the particle size due to the formation of PANI around the particles. It is interesting to note that the polymerization yield is slightly increased for PANI-50 which indicates that polymerization is mainly initiated on the particle surface. The PANI-nanoTiO2 dispersed in PVB solution and studied for corrosion resistance by accelerated immersion test in 3.5% saline solution at 65 0 C followed by Tafel tests. The Tafel plots of figure: 2 shows that corrosion protection of steel enhanced by the addition of increasing concentration of TiO2.Because TiO2 improves the barrier properties. Nano TiO2 acts as noble metal and it may form a thin layer on the metal surface. The n-type nanoTiO2 and p-type PANI forms p-n type junction which give potential barrier to charge transport. Also barrier to the diffusions of ions is improved due to nano-particles. Log current(I/A) -6.0 -6.5 -7.0 -7.5 -8.0 -8.5 -9.0 -9.5 -10.0 -10.5 0.0% TiO2 1.3% TiO 2 2.85% TiO 2 2.3% TiO 2 4.18% TiO 2 -0.35 -0.30 -0.25 -0.20 -0.15 -0.10 P o te ntia l(V ) Figure:2. Tafel plots of accelerated PVB-PANI/TiO2 coating after 40 hrs. The open circuit potentials (OCP) determined from these plots recorded after different time of exposure to hot saline environment are indicated in Figure 3. The initial OCP of PVB is found to be on the cathodic side but more positive (-0.48) than that of bare steel (-0.6V SCE) [20] but after prolonged exposure to corrosive environment, the OCP shifts to more cathodic region. On the
Page 1 and 2:
Design of experiments for optimizin
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Verification Experiments Confirmato
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Fig 3 Overlaid contour plots for te
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processing variables on the adhesio
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NR / CR TSC (%) 100 / 0 75 / 25 50
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the observed high values of its T-p
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Nondestructive testing of defects i
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visible impact damage (BVID). The c
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Fig 2. Photograph of the spliced ne
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Electrical studies on silver subsur
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temperatures exhibited by the 50 nm
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Figure 1: Variation of ln R with 1/
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Experimental Polyamide6 (PA6 with z
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Table 1: Sample code and compositio
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Blends of unsaturated polyester res
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in comparison to that of the base r
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Fig. 1 Tensile strength of rubber m
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characterization of PTT/m-LLDPE ble
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organoclay into the blend matrix re
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Figure: 5 - DSC cooling thermogram
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polypropylene exhibits β-chain sci
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ehavior. Here two possible effects
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Complex modulus (KPa) Complex visco
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has been carried out using thermogr
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Weight (%) 80 40 0 Table 1. Sample
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Mechanical properties of natural ru
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due to adsorption on rubber particl
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Preparation and Characterization of
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2.7. Fabrication of curcumin elutin
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Table 2. Effect of curcumin content
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Biodegradable nanocomposites can be
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crystallization temperature of PBAT
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Biomimetic synthesis of nanohybrids
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3.3. Thermogravimetric analysis (TG
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Fig 2: 31 P-NMR Spectra of as-synth
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In this work we have examined the c
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7. George, K.M, Alex, R, Joseph, S
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Reinforcement studies - Effect of t
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Results and Discussion Immersion an
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Stress (MPa) 26 24 22 20 18 16 14 1
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Effect of plasticizer, filler and s
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Results and Discussion Properties o
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prepolymers having higher percentag
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Table2. Formulation for Peroxide cu
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Elongation at Break The elongation
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All-PP composites based on β and
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a T E'(T) = (1) E'(T ) ref The shif
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We tried the classical WLF equation
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Figure 2. Schematic of time-tempera
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Intercalated poly (methyl methacryl
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them. The nanocomposites prepared u
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Table 1: Mechanical Properties of P
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Abstract A Review on thermally stab
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processing of different commercial
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d(%Mass)/dT ( 0 d(%Mass)/dT ( C) 0
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composites has been reported to imp
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(a) (b) Figure 2: WAXD of a) PVC/mi
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Storage Modulus (M Pa) 3000 2500 20
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17. Peprnicek, T.; Duchet, J.; Kova
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constraint of several nanometers, t
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The FT-IR spectrum .ER-Epoxy resin,
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GLASS TRANSITION TEMPERATURE (Tg) V
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AFM image of Amine containing PDMS
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8. A.Al.Abrash, F.Al.Sagheer, A.A.m
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2. Experimental Details Polypropyle
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5. Acknowlegements We would like to
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Synthesis and characterization of p
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pristine polypropylene during cooli
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a Figure 2: Typical TEM micrographs
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potassium ditelluratoargentate (III
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found to be 80.51 and 77.31, respec
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14. G. Canche-Escamilla, J.I. Cauic
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2.2. Characterization of electrospu
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eported that tortuosity decreases w
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Abstract: Effect of nano TiO2 in co
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3. Results and Discussion : The wid
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This is further evidenced from the
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Transducer using Terfenol-D/epoxy c
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esults were compared. Measurements
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500 400 300 200 100 0 Magnetostrict
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Experimental Materials Natural crum
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It is known that for alkali and alk
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Polymer sample Table1. Ion uptake b
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Abstract Protein functionalized pol
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2.4 Analysis of Particle size of ul
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Table 1 Nano particle preparation o
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As the particle size is reduced, su
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Figure- 3 SEM micrograph of EFNP of
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Excess PVA solution was drained off
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Figure 1. IR spectra of (I) PSF bas
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Photodegradable polypropylene film
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were observed as a broad peak in th
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Fig. 1. Carbonyl index variation of
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Abstract Swelling behaviour of hydr
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Swelling experiment Circular shaped
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⎛ hθ D = π⎜ ⎜ ⎝ 4Q ∞
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21. Bajsic G, Rek V. J Appl Polym S
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log (C α - C t ) 1.0 0.9 0.8 0.7 0
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esistance [2]. For converting it to
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References 1. Bob RJ, Underwater El
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Figure-2 Insertion Loss behavior 0.
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Development of epoxy based material
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NOTATIONS USED A→E-55, AL-45.S.g-
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The Samples E, I, H and pure epoxy
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The combination B The combination I
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Graft-copolymerization of cellulose
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Once the free-radical species (A
Page 216 and 217:
References 1. Margaret I.P, Sau L.L
Page 218 and 219:
Design of experiments for optimizin
Page 220 and 221:
Verification Experiments Confirmato
Page 222 and 223:
Fig 3 Overlaid contour plots for te
Page 224 and 225:
processing variables on the adhesio
Page 226 and 227:
NR / CR TSC (%) 100 / 0 75 / 25 50
Page 228 and 229:
the observed high values of its T-p
Page 230 and 231:
Nondestructive testing of defects i
Page 232 and 233:
visible impact damage (BVID). The c
Page 234 and 235:
Fig 2. Photograph of the spliced ne
Page 236 and 237:
Electrical studies on silver subsur
Page 238 and 239:
temperatures exhibited by the 50 nm
Page 240 and 241:
Figure 1: Variation of ln R with 1/
Page 242 and 243:
Experimental Polyamide6 (PA6 with z
Page 244 and 245:
Table 1: Sample code and compositio
Page 246 and 247:
Blends of unsaturated polyester res
Page 248 and 249:
in comparison to that of the base r
Page 250 and 251:
Fig. 1 Tensile strength of rubber m
Page 252 and 253:
characterization of PTT/m-LLDPE ble
Page 254 and 255:
organoclay into the blend matrix re
Page 256 and 257:
Figure: 5 - DSC cooling thermogram
Page 258 and 259:
polypropylene exhibits β-chain sci
Page 260 and 261:
ehavior. Here two possible effects
Page 262 and 263:
Complex modulus (KPa) Complex visco
Page 264 and 265:
has been carried out using thermogr
Page 266 and 267:
Weight (%) 80 40 0 Table 1. Sample
Page 268 and 269:
Mechanical properties of natural ru
Page 270 and 271:
due to adsorption on rubber particl
Page 272 and 273:
Preparation and Characterization of
Page 274 and 275:
2.7. Fabrication of curcumin elutin
Page 276 and 277:
Table 2. Effect of curcumin content
Page 278 and 279:
Biodegradable nanocomposites can be
Page 280 and 281:
crystallization temperature of PBAT
Page 282 and 283:
Biomimetic synthesis of nanohybrids
Page 284 and 285:
3.3. Thermogravimetric analysis (TG
Page 286 and 287:
Fig 2: 31 P-NMR Spectra of as-synth
Page 288 and 289:
In this work we have examined the c
Page 290 and 291:
7. George, K.M, Alex, R, Joseph, S
Page 292 and 293:
Reinforcement studies - Effect of t
Page 294 and 295:
Results and Discussion Immersion an
Page 296 and 297:
Stress (MPa) 26 24 22 20 18 16 14 1
Page 298 and 299:
Effect of plasticizer, filler and s
Page 300:
Results and Discussion Properties o
Page 303 and 304:
prepolymers having higher percentag
Page 305 and 306:
Table2. Formulation for Peroxide cu
Page 307 and 308:
Elongation at Break The elongation
Page 309 and 310:
All-PP composites based on β and
Page 311 and 312:
a T E'(T) = (1) E'(T ) ref The shif
Page 313 and 314:
We tried the classical WLF equation
Page 315 and 316:
Figure 2. Schematic of time-tempera
Page 317 and 318: Intercalated poly (methyl methacryl
Page 319 and 320: them. The nanocomposites prepared u
Page 321 and 322: Table 1: Mechanical Properties of P
Page 323 and 324: Abstract A Review on thermally stab
Page 325 and 326: processing of different commercial
Page 327 and 328: d(%Mass)/dT ( 0 d(%Mass)/dT ( C) 0
Page 329 and 330: composites has been reported to imp
Page 331 and 332: (a) (b) Figure 2: WAXD of a) PVC/mi
Page 333 and 334: Storage Modulus (M Pa) 3000 2500 20
Page 335 and 336: 17. Peprnicek, T.; Duchet, J.; Kova
Page 337 and 338: constraint of several nanometers, t
Page 339 and 340: The FT-IR spectrum .ER-Epoxy resin,
Page 341 and 342: GLASS TRANSITION TEMPERATURE (Tg) V
Page 343 and 344: AFM image of Amine containing PDMS
Page 345 and 346: 8. A.Al.Abrash, F.Al.Sagheer, A.A.m
Page 347 and 348: 2. Experimental Details Polypropyle
Page 349 and 350: 5. Acknowlegements We would like to
Page 351 and 352: Synthesis and characterization of p
Page 353 and 354: pristine polypropylene during cooli
Page 355 and 356: a Figure 2: Typical TEM micrographs
Page 357 and 358: potassium ditelluratoargentate (III
Page 359 and 360: found to be 80.51 and 77.31, respec
Page 361 and 362: 14. G. Canche-Escamilla, J.I. Cauic
Page 363 and 364: 2.2. Characterization of electrospu
Page 365 and 366: eported that tortuosity decreases w
Page 367: Abstract: Effect of nano TiO2 in co
Page 371 and 372: This is further evidenced from the
Page 373 and 374: Transducer using Terfenol-D/epoxy c
Page 375 and 376: esults were compared. Measurements
Page 377 and 378: 500 400 300 200 100 0 Magnetostrict
Page 379 and 380: Experimental Materials Natural crum
Page 381 and 382: It is known that for alkali and alk
Page 383 and 384: Polymer sample Table1. Ion uptake b
Page 385 and 386: Abstract Protein functionalized pol
Page 387 and 388: 2.4 Analysis of Particle size of ul
Page 389 and 390: Table 1 Nano particle preparation o
Page 391 and 392: As the particle size is reduced, su
Page 393 and 394: Figure- 3 SEM micrograph of EFNP of
Page 395 and 396: Excess PVA solution was drained off
Page 397 and 398: Figure 1. IR spectra of (I) PSF bas
Page 399 and 400: Photodegradable polypropylene film
Page 401 and 402: were observed as a broad peak in th
Page 403 and 404: Fig. 1. Carbonyl index variation of
Page 405 and 406: Abstract Swelling behaviour of hydr
Page 407 and 408: Swelling experiment Circular shaped
Page 409 and 410: ⎛ hθ D = π⎜ ⎜ ⎝ 4Q ∞
Page 411 and 412: 21. Bajsic G, Rek V. J Appl Polym S
Page 413 and 414: log (C α - C t ) 1.0 0.9 0.8 0.7 0
Page 415 and 416: esistance [2]. For converting it to
Page 417 and 418: References 1. Bob RJ, Underwater El
Page 419 and 420:
Figure-2 Insertion Loss behavior 0.
Page 421 and 422:
Development of epoxy based material
Page 423 and 424:
NOTATIONS USED A→E-55, AL-45.S.g-
Page 425 and 426:
The Samples E, I, H and pure epoxy
Page 427 and 428:
The combination B The combination I
Page 429 and 430:
Graft-copolymerization of cellulose
Page 431 and 432:
Once the free-radical species (A
Page 433 and 434:
References 1. Margaret I.P, Sau L.L
Page 435 and 436:
Studies on processing of styrene bu
Page 437 and 438:
3 Results 4. Swelling index - Tolue
Page 439:
4. Swelling index The swelling indi
Page 442 and 443:
Effect of post drawing parameters o
Page 444 and 445:
Drawing the fiber at 100 0 C, which
Page 446 and 447:
Table 1: Experimental details of va
Page 448 and 449:
and the primary variables in the go
Page 450 and 451:
The equ (3.2) is linearized and we
Page 452 and 453:
Initial Deformed coordinates coordi
Page 454 and 455:
As 'C' channel structures is non-sy
Page 456 and 457:
Figure 3: Von-mises stress distribu
Page 458 and 459:
Synthesis, curing and characterizat
Page 460 and 461:
Results and Discussion: . Table 4.1
Page 462 and 463:
TGDDM/DDM SYSTEM: There are 2 trans
Page 464 and 465:
Table 4.6: DSC Results DSC thermo g
Page 466 and 467:
CONCLUSION: 1. Tetraglycidyl Diamin
Page 468 and 469:
Studies on processing of styrene bu
Page 470 and 471:
3 Results 4. Swelling index - Tolue
Page 472:
4. Swelling index The swelling indi
Page 475 and 476:
Effect of post drawing parameters o
Page 477 and 478:
Drawing the fiber at 100 0 C, which
Page 479 and 480:
Table 1: Experimental details of va
Page 481 and 482:
and the primary variables in the go
Page 483 and 484:
The equ (3.2) is linearized and we
Page 485 and 486:
Initial Deformed coordinates coordi
Page 487 and 488:
As 'C' channel structures is non-sy
Page 489 and 490:
Figure 3: Von-mises stress distribu
Page 491 and 492:
Synthesis, curing and characterizat
Page 493 and 494:
Results and Discussion: . Table 4.1
Page 495 and 496:
TGDDM/DDM SYSTEM: There are 2 trans
Page 497 and 498:
Table 4.6: DSC Results DSC thermo g
Page 499 and 500:
CONCLUSION: 1. Tetraglycidyl Diamin
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