Nondestructive testing of defects in adhesive joints

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Preparation of polyvinylalcohol based thin film composite nanofiltration membranes: Application in the removal of hardness from brackish water J.M.Gohil * and P.Ray # Reverse Osmosis Discipline, Central Salt and Marine Chemicals Research Institute (CSIR), Bhavnagar, Gujarat, India. E-mail: paramita022002@yahoo.co.in Abstract Polyvinyl alcohol (PVA) (degree of hydrolysis 86-87%), crosslinked with maleic acid (MA) has been used successfully as barrier layer of polysulphone (PSF) based thin film composite (TFC) membranes. The crosslinking of PVA and its presence in PSF matrix has been established by FTIR and contact angle study. PVA TFC membranes show dense phase morphology. The effect of variation of crosslinker (MA) dose, cure time and temperature on membrane performance (flux and rejection of inorganic salts) have been studied and the optimum membrane compositions were evaluated. Such membranes show differential rejection among the sulphate and chloride salts. On an average 65% difference exists between the rejection of MgSO4 (70-90%) and NaCl (15-35%). The overall trend of rejection by such membranes is > > R 2 4 SO Na R RMgSO NaCl > R ≅ (R = Rejection). The average molecular weight cutoff 4 MgCl R 2 CaCl2 (MWCO) of such membranes varies between 250-450 Dalton. These membranes may be useful for the removal of dissolved sulphates (salts) and partial desalination of brackish water. Introduction Pressure driven membranes have acquired a significant position in the area of separation science and technology [1]. Nanofiltration (NF) membranes are relatively new class of charged pressure driven membranes. Due to preferential selectivity towards ions, lower operating pressure and higher flux, NF membranes have wide scope of applications in water and waste-water treatment [2, 3]. Hard water is probably the most common water problem found not only at home but also in the industries causing scaling in boilers, cooling towers, pipelines and other industrial equipments. Treatment of hard water with nanofiltration membranes may be a unique solution to produce soft water. Polyvinyl alcohol (PVA) being a water soluble biodegradable polymer has immense potential as a membrane material because of its high water permeation and film forming characteristics [4, 5]. Additionally presence of innumerable number of hydroxyl groups in this polymer may impart a charge effect in closer vicinity and make the membrane suitable to act as nanofiltration membranes with preferential rejection towards multivalent ions than the monovalent ones. The main target of the work is to prepare polysulphone based thin film composite membranes with PVA as the selective barrier layer. The membrane composition has been optimized and the rejection trends of such membranes in different mono and bivalent salts have been evaluated. Experimental Materials: Poly (vinyl alcohol) (PVA), with Mol. Wt. 1, 25,000, degree of hydrolysis 86-87%, Sodium chloride, Magnesium chloride, Calcium chloride, Magnesium sulfate, Sodium sulfate, Glycerol , all AR grade , supplied by SD Fine Chemicals, India. D-Glucose Anhydride, LR grade, supplied by NICE Chemicals; Sucrose, LR grade, supplied by SRL; Raffinose pentahydrate, LR grade, supplied by Loba Chemie. Membrane Preparation Method: PVA solution 1% (w/w) (containing different dose of MA) was poured on PSF ultrafiltration membrane (prepared by phase inversion technique and acted as a porous support) mounted on a glass plate [6, 7].
Excess PVA solution was drained off and the membranes were dried at ambient temperature. The membranes were subsequently heated in oven at a temperature of 125±2 ºC for 30 minutes. Characterization of Membranes: FT-IR: The IR spectrum of PSF ultrafiltration and cross-linked PVA TFC membranes (of size 6 cm × 3 cm) were recorded in the middle infrared region using a Perkin Elmer 400 FT-IR spectrometer. Contact angle (θ): Contact angle of resulting PVA TFC membranes was studied by Wilhelmy plate method using Dynamic Contact Angle Tensiometer (DCAT 21, Data Physics). Scanning electron microscopy (SEM): Phase morphology (Cross-sectional and topography) of the membranes were studied using Leo microscope at 15 kV accelerating voltage. Membranes performance testing: The salt rejection characteristics of membranes were studied in RO test cell by passing aqueous feed solutions of mono and bivalent salts separately through the membranes at different pressure (150-350 psi). Permeate flux was studied and solute rejection was calculated with the help of equation 1. The concentrations of inorganic salts in feed and permeate were determined by inductively coupled plasma spectrometry (ICP), chemical analysis and conductivity measurements. ⎡ Concentrationof solutein permeate⎤ Soluterejection( R) (%) = ⎢1 − ⎥× 100 ( 1) ⎣ Concentrationof solutein feed ⎦ Molecular weight cut-off (MWCO): A mixed solution containing glucose, sucrose, raffinose and glycerol each of 500 ppm was passed through the membranes. The percent organic solute in feed and permeate was analyzed by High performance liquid chromatography (HPLC) and Total organic carbon (TOC) analysis. The solute rejection was calculated by using the formula 1. The solute rejection above 85% was taken as MWCO of membranes. Result and Discussion The base PSF substrate was prepared from 17% PSF solution and PVA layer was coated with 1% PVA solution containing MA as curative in the concentration range from 2-50% (w/w with respect to PVA). The IR spectrum of PSF base substrate membrane is shown in figure 1(graph I). The existence of PVA at the surface of PSF TFC membranes is indicated by the peak at 3,200-3,400 cm -1 (Figure1, graph II), which is the characteristics of OH of PVA. The peak at 1,335 cm -1 is due to the ester linkages formed by the cross-linking of PVA with MA. Contact angle reflects the hydrophilicity of any surface. PVA coating provides the hydrophilicity to hydrophobic PSF membranes. The hydrophilic nature of PVA TFC membranes are reflected by their average lower contact angle (81º) value compare to that of hydrophobic PSF membranes (89.5 º). Cross sectional morphology of PSF membranes show a wide open pore structure (Figure 2A). However coating of PVA partially masks the polysulphone layer and overall reduction in the average pore size is observed (Figure 2B). Effect of different process parameters on membranes performance: Effect of variation of curative dose on membrane performance: To see the effect of MA concentration on stability of rejection layer, the flux (Figure 3) and rejection (Figure 4) profiles of the membranes (varying in the cross-link density of the rejection layer) were tested in continuous mode for a period of 24 hours using 500 ppm MgSO4 solution. The membranes were cured at a temperature of 125±2 ºC for duration of 30 minutes. It is observed from Figure 3 that lowers the curative dose higher the membrane flux. However all the membranes show almost consistent flux over the studied period irrespective of the crosslinker dose. It is also observed (Figure 4) that in the rejection profiles there is a slight fall with time for membranes prepared with lower curative dose of 2 and 5% MA. However for MA dose >5% the rejection remains constant with time. Hence 5-10% concentration of MA may be considered as optimum for curing of such membranes. Effect of cure time on membrane performance: Membranes were prepared from 17% PSF and 1% PVA-1 with MA concentration of 10% (w/w) cured by varying the cure time from 10-40 minutes at a temperature 2
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
Page 186 and 187:
Fig. 1. Carbonyl index variation of
Page 188 and 189:
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 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: Figure- 3 SEM micrograph of EFNP of
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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