Nondestructive testing of defects in adhesive joints

More documents

Recommendations

Info

were observed as a broad peak in the region of 1800 – 1700 cm -1 in the FTIR spectrum of weathered PP due to the overlap of different degradation products like lactone, ester, ketone, carboxylic acid, etc [12]. The carboxylic acid group concentration (Fig. 2) is higher while the lactone concentration is low because the carboxylic acid is the final stable product of degradation [13]. A similar trend was observed in the study of polypropylene natural weathering at Messina, Italy by Gallo et al.[14]. Hydroperoxide is the initial product of photooxidative degradation of PP and hence hydroperoxide group formation and its decomposition in the course of natural weathering is an important aspect, which may justify the faster degradation of materials. The hydroperoxide index was calculated as the ratio of the maximum absorbance at 3445 cm -1 to the absorbance at 974 cm -1 . From Figs. 1, 3a and 3b, the concomitant increase of the hydroperoxide groups and the carbonyl groups are explicit. It reveals that hydroperoxide formation and its decomposition take place simultaneously since the generated tertiary hydroperoxide is unstable. A similar trend has also been observed in the case of hydroxyl index variation. In the case of photooxidation of PP, vinylidene group formation is the most probable one when compared to the vinyl group due to the presence of pendent methyl group. The vinylidene index was calculated as the ratio of absorbance at 888 cm -1 to the reference peak absorbance at 974 cm -1 . An irregular trend has been observed for this index. Certain environmental conditions lead to the consumption of this group to produce free radicals, whereas some environmental features favour the formation of this group. In order to gather information regarding the variation of crystallinity as a function of outdoor exposure days, the ratio of absorbance at 998 cm -1 to the absorbance at 974 cm -1 was used to calculate the crystallinity index. The first band is regularity band characteristic of the crystalline PP, whereas the second band corresponds to both crystalline and amorphous phases of PP. In Figs. 1-3, it is clear that as the hydroperoxide, hydroxyl, carbonyl, lactone, ester, carboxylic acid, etc., indices increases, the crystallinity index is also increasing. This may be explained due to the formation of new low molecular weight photooxidation products capable of forming new crystalline domains. Measurements of Tensile Properties The elongation at break (%) can be frequently used to monitor the degradation of polymers. From Fig. 4, it is found that in the case of PP virgin, the elongation at break shows slight variation up to 45 days of exposure and then a sudden drop is seen. The value reaches near zero value soon indicating main chain scission in the polymer molecule. But, in the case of prodegradant added PP materials, the elongation properties are lost within 15 days of exposure, thereby rendering the film useless for practical applications. Tensile strength is an important measure of product quality to certify the product and therefore its variation during weathering is one of the important parameter used to follow degradation. In almost all cases, PP films and PP containing prodegradant, tensile strength decreased considerably at the initial stages of weathering. Then a gradual decrease is noted and finally there is a sudden drop in the tensile strength values. This phenomenon may be attributed to chain reorganization and/or lower degree of orientation during natural weathering. SEM studies The scanning electron micrographs of weathered PP virgin (45 days) and its blend with MF01 (11 days) films are shown in Fig. 5. The SEM images clearly show the formation of cracks in the weathered material. The increase in carbonyl index, the decrease in elongation at break and the formation of cracks are enhanced at a much earlier stage when the prodegradant is added to PP.
Conclusion A steep increase of carbonyl, hydroperoxide, hydroxyl, lactone, ester, carboxylic acid and crystallinity indices and a sudden decrease of elongation at break and tensile strength indicate the occurrence of main chain scissions in the materials investigated. Further, from the above results one can reasonably conclude that the added prodegradant (ferric stearate) plays an important role in initiating the photodegradation of polypropylene during weathering. Other weather parameters like temperature, UV intensity, visible light intensity, etc., are contribute substantially to the photooxidative degradation of the material. References 1. Barenberg SA. In: Brash JL, Narayan R, Redpath AE, editors. Degradable Materials, Boston: CRC Press, 1990. pp. 559-583. 2. Misklczi N, Bartha L, Deak G, Jovev B. Polym Degrad Stab 2004; 86:357. 3. Aguado J, Serrano DP, Guillet JE. In: Clark JH, editor. Polymers and Ecological Problems, New York: Plenum Press, 1973. 4. Scott GJ. Polym Sci Symp 1976; 57:357. 5. Griffin JGL. In: Chemistry and technology of biodegradable polymers, London: Blackie Academic and Professional, 1994 (chapters 1-3). 6. Scott G. Degradable Polymers: Principles and Applications, London: Chapman & Hall, 1995 (chapter 9). 7. Scott G. Polymers and the Environment, Cambridge: Royal Society of Chemistry, 1999 (chapter 2). 8. Roder H, Vogl O. Prog Polym Sci 1999; 24:1205. 9. David C. Trojan M. Demarteau DA. Polym Degrad Stab 1992; 37:233. 10. Sheikh N, Akhavan A, Naiman F, Kholou F, Hasanpour S, Sohrabpour M. J Polym Env 2006; 14:103. 11. Carlsson DJ, Wiles DM. J Polym Rev 1976; 14:65. 12. Hamid SH, Prichard WH. Polym Plast Technol Eng 1988; 27:303. 13. Morlat S, Mailhot B, Gonzalez D, Gardette J. Chem Mater 2004; 16:377. 14. Gallo R, Severini F, Ipsale S, Fanti ND. Polym Degrad Stab 1997; 55:199. Table 1. Characteristic infrared absorption frequencies Functional Group Frequency Range (cm -1 ) Hydroxyl and Hydroperoxide 3600 - 3200 Carbonyl 1800 – 1700 Ketone 1725 – 1715 Carboxylic Acid 1712 – 1705 Ester 1750 – 1735 Lactone 1785 – 1760 Vinyl 909 Vinylidene 888
Page 1 and 2:
Design of experiments for optimizin
Page 3 and 4:
Verification Experiments Confirmato
Page 5 and 6:
Fig 3 Overlaid contour plots for te
Page 7 and 8:
processing variables on the adhesio
Page 9 and 10:
NR / CR TSC (%) 100 / 0 75 / 25 50
Page 11 and 12:
the observed high values of its T-p
Page 13 and 14:
Nondestructive testing of defects i
Page 15 and 16:
visible impact damage (BVID). The c
Page 17 and 18:
Fig 2. Photograph of the spliced ne
Page 19 and 20:
Electrical studies on silver subsur
Page 21 and 22:
temperatures exhibited by the 50 nm
Page 23 and 24:
Figure 1: Variation of ln R with 1/
Page 25 and 26:
Experimental Polyamide6 (PA6 with z
Page 27 and 28:
Table 1: Sample code and compositio
Page 29 and 30:
Blends of unsaturated polyester res
Page 31 and 32:
in comparison to that of the base r
Page 33 and 34:
Fig. 1 Tensile strength of rubber m
Page 35 and 36:
characterization of PTT/m-LLDPE ble
Page 37 and 38:
organoclay into the blend matrix re
Page 39 and 40:
Figure: 5 - DSC cooling thermogram
Page 41 and 42:
polypropylene exhibits β-chain sci
Page 43 and 44:
ehavior. Here two possible effects
Page 45 and 46:
Complex modulus (KPa) Complex visco
Page 47 and 48:
has been carried out using thermogr
Page 49 and 50:
Weight (%) 80 40 0 Table 1. Sample
Page 51 and 52:
Mechanical properties of natural ru
Page 53 and 54:
due to adsorption on rubber particl
Page 55 and 56:
Preparation and Characterization of
Page 57 and 58:
2.7. Fabrication of curcumin elutin
Page 59 and 60:
Table 2. Effect of curcumin content
Page 61 and 62:
Biodegradable nanocomposites can be
Page 63 and 64:
crystallization temperature of PBAT
Page 65 and 66:
Biomimetic synthesis of nanohybrids
Page 67 and 68:
3.3. Thermogravimetric analysis (TG
Page 69 and 70:
Fig 2: 31 P-NMR Spectra of as-synth
Page 71 and 72:
In this work we have examined the c
Page 73 and 74:
7. George, K.M, Alex, R, Joseph, S
Page 75 and 76:
Reinforcement studies - Effect of t
Page 77 and 78:
Results and Discussion Immersion an
Page 79 and 80:
Stress (MPa) 26 24 22 20 18 16 14 1
Page 81 and 82:
Effect of plasticizer, filler and s
Page 83:
Results and Discussion Properties o
Page 86 and 87:
prepolymers having higher percentag
Page 88 and 89:
Table2. Formulation for Peroxide cu
Page 90 and 91:
Elongation at Break The elongation
Page 92 and 93:
All-PP composites based on β and
Page 94 and 95:
a T E'(T) = (1) E'(T ) ref The shif
Page 96 and 97:
We tried the classical WLF equation
Page 98 and 99:
Figure 2. Schematic of time-tempera
Page 100 and 101:
Intercalated poly (methyl methacryl
Page 102 and 103:
them. The nanocomposites prepared u
Page 104 and 105:
Table 1: Mechanical Properties of P
Page 106 and 107:
Abstract A Review on thermally stab
Page 108 and 109:
processing of different commercial
Page 110 and 111:
d(%Mass)/dT ( 0 d(%Mass)/dT ( C) 0
Page 112 and 113:
composites has been reported to imp
Page 114 and 115:
(a) (b) Figure 2: WAXD of a) PVC/mi
Page 116 and 117:
Storage Modulus (M Pa) 3000 2500 20
Page 118 and 119:
17. Peprnicek, T.; Duchet, J.; Kova
Page 120 and 121:
constraint of several nanometers, t
Page 122 and 123:
The FT-IR spectrum .ER-Epoxy resin,
Page 124 and 125:
GLASS TRANSITION TEMPERATURE (Tg) V
Page 126 and 127:
AFM image of Amine containing PDMS
Page 128 and 129:
8. A.Al.Abrash, F.Al.Sagheer, A.A.m
Page 130 and 131:
2. Experimental Details Polypropyle
Page 132 and 133:
5. Acknowlegements We would like to
Page 134 and 135: Synthesis and characterization of p
Page 136 and 137: pristine polypropylene during cooli
Page 138 and 139: a Figure 2: Typical TEM micrographs
Page 140 and 141: potassium ditelluratoargentate (III
Page 142 and 143: found to be 80.51 and 77.31, respec
Page 144 and 145: 14. G. Canche-Escamilla, J.I. Cauic
Page 146 and 147: 2.2. Characterization of electrospu
Page 148 and 149: eported that tortuosity decreases w
Page 150 and 151: Abstract: Effect of nano TiO2 in co
Page 152 and 153: 3. Results and Discussion : The wid
Page 154 and 155: This is further evidenced from the
Page 156 and 157: Transducer using Terfenol-D/epoxy c
Page 158 and 159: esults were compared. Measurements
Page 160 and 161: 500 400 300 200 100 0 Magnetostrict
Page 162 and 163: Experimental Materials Natural crum
Page 164 and 165: It is known that for alkali and alk
Page 166 and 167: Polymer sample Table1. Ion uptake b
Page 168 and 169: Abstract Protein functionalized pol
Page 170 and 171: 2.4 Analysis of Particle size of ul
Page 172 and 173: Table 1 Nano particle preparation o
Page 174 and 175: As the particle size is reduced, su
Page 176 and 177: Figure- 3 SEM micrograph of EFNP of
Page 178 and 179: Excess PVA solution was drained off
Page 180 and 181: Figure 1. IR spectra of (I) PSF bas
Page 182 and 183: Photodegradable polypropylene film
Page 186 and 187: Fig. 1. Carbonyl index variation of
Page 188 and 189: Abstract Swelling behaviour of hydr
Page 190 and 191: Swelling experiment Circular shaped
Page 192 and 193: ⎛ hθ D = π⎜ ⎜ ⎝ 4Q ∞
Page 194 and 195: 21. Bajsic G, Rek V. J Appl Polym S
Page 196 and 197: log (C α - C t ) 1.0 0.9 0.8 0.7 0
Page 198 and 199: esistance [2]. For converting it to
Page 200 and 201: References 1. Bob RJ, Underwater El
Page 202 and 203: Figure-2 Insertion Loss behavior 0.
Page 204 and 205: Development of epoxy based material
Page 206 and 207: NOTATIONS USED A→E-55, AL-45.S.g-
Page 208 and 209: The Samples E, I, H and pure epoxy
Page 210 and 211: The combination B The combination I
Page 212 and 213: Graft-copolymerization of cellulose
Page 214 and 215: 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 and 368:
Abstract: Effect of nano TiO2 in co
Page 369 and 370:
3. Results and Discussion : The wid
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
show all

Nondestructive testing of defects in adhesive joints

Create successful ePaper yourself

Delete template?

Save as template?