New High Temperature Resistant Vinyl Ester

Transcription

1 New High Temperature Resistant Vinyl Ester Bruce Curry September, 2005 ABSTRACT There has been a need for a high temperature resistant vinyl ester for pipes to carry hot gases, for reinforcement in dual laminates and for applications such as quench vessels A new high temperature resistant vinyl ester has been developed with a heat distortion temperature of 0 F (5 C) Liquid resin properties, cast mechanical properties, laminate mechanical properties, hardness development and some initial corrosion resistant properties of this new vinyl ester resin will be provided INTRODUCTION Options for the development of high heat resistant resins are polyesters and vinyl esters Since vinyl esters have inherently better impact resistance than polyesters, a high temperature resistant novolac vinyl ester was developed Engineers often need mechanical properties on castings and on ASME RTP- laminates High temperature tensile properties of both the casting and the ASME RTP- laminate were tested and the results will be presented High temperature tensile properties were obtained because tensile modulus values are required by engineers to design fiberglass equipment for high temperature applications Corrosion test results in toluene and methanol at 00 F (78 C) as well as resistance to 50 F (77 C) air were obtained Comparisons will be made to standard novolac resins Results of bisphenol vinyl esters will also be included since they are the most common vinyl esters sold The new high temperature novolac resin will be referred to as F08 The standard novolac resin will be called F085 A standard bisphenol A epoxy vinyl ester will be called F00 EXPERIMENTAL Certain key requirements were imposed Styrene content must be =5% Resin cast heat distortion must be >25 F (28 C) F08 resin should cure similar to F085 and F00 The Vipel F08 high temperature resistance of cast and ASME RTP- laminate should be higher than that of Vipel F00 and Vipel F085 The corrosion resistance of Vipel F08 to toluene and methanol at 00 F (78 C) plus air at 50 F (77 C) air must equal or exceed that of Vipel F00 and Vipel F085 TEST PROCEDURE Several polymers made with novolac epoxy resins were pre- pared using the standard system of end capping the polymer with methacrylic acid Liquid properties including viscosity, gel, styrene contents, Barcol Hardness development, etc were tested with standard equipment and methods that are typically used in the industry The cast preparation is found in figure ASME RTP- and ASTM C 58 laminates were post cured following the post cure schedule of the castings ASME RTP - laminates were made with one layer of veil, three plies of 5 ounce per square foot mat(450 grams per square meter), one ply of 24 ounce per square yard (84 grams per square meter) woven roving, one layer of mat, one layer of C glass veil on each side Flexural strength and flexural modulus was tested on the control laminates The laminates were then placed in toluene and methanol at 00 F (78 C) for,, and months After each of these time periods, the laminates were removed from the oven, allowed to stabilize at ambient temperature and then were tested Likewise, coupons were placed in a 50 F (77 C)

2 oven and removed at,, and 9 months They were allowed to return to ambient temperature and then were tested Secondary bonding was simply tested by prying two laminates apart Resins were promoted with 0% cobalt %, 005% N,Ndimethylaniline and catalyzed with 20% cumyl hydroperoxide Vipel F00, Vipel F085 and Vipel F08 resins were used to prepare laminates with plies of 5 ounce chopped strand mat that were 5 inches (8 cm) by 8 (20 cm) inches After 5 days a strip of Mylar, one inch wide, was placed on the 5 (8 cm) inch end of each of these laminates Another laminate was applied over each of the original laminates and allowed to cure for days Then a wedge was used to pry the laminates apart starting a plastic release film RESULTS a) Vipel F08 that contains 5% styrene was produced See figure 2 b) The heat distortion of Vipel F08 is 0 F (5) c) The laminate cure rate of Vipel F08 is similar to that of Vipel F085 and somewhat faster than Vipel F00 See figure Cast and ASME RTP- laminates high temperature tensile properties of Vipel F08, Vipel F085 and Vipel F00 were obtained and are shown on figure 5,, 7 and 8 F08 retained more mechanical strength at high temperatures than Vipel F085 and Vipel F00 The high temperature tensile properties retention of a laminate is much greater than that of a casting Thus the glass reinforcement has a significant effect on this property d) The glass contents of Vipel F08, Vipel F085 and Vipel F00 laminates were -40% e) Vipel F08 and Vipel F085 have similar resistance to methanol and toluene after months Based on Barcol Hard- ness values, both Vipel F08 and Vipel F085 have better resistance to methanol and toluene than Vipel F00, as expected See figures 9, 0,, 2, and 4 f) ASTM C 58 laminates of Vipel F08, Vipel F085 and Vipel F00 were exposed to 50 F (77 C) air for 9 months See figure 7 and 8 Flexural strength, flexural modulus, Barcol Hardness were all similar Both Vipel F085 and Vipel F08 retained more weight than did the Vipel F00 See figures 5, and 7 g) All laminates bonded well in this test DISCUSSION A standard cumyl hydroperoxide which is also known as cumene hydroperoxide (CHP) catalyst is suggested for novolacs since they are quite reactive One advantage to using CHP over MEKP catalysts is that foaming is not an issue Even though a good secondary bond was obtained, there have been a number of reported instances of delamination when the surface of a novolac laminate was not ground before applying the secondary laminate Thus it would be prudent to sand the surface with a -24 grit grinding pad before applying a second laminate Like Vipel F085 resins, the Vipel F08 is not recommended for caustic environments Vipel F00 resins can be used in caustic environments APPLICATIONS Vipel F08 is suited to reinforce thermoplastic liners in dual laminate applications where high heat resistance is needed Vipel F08 is also suited for hot chemical environments such as carrying hot gases or for quench vessels when extra assurance is needed over the marginal heat resistant and corrosion resistant offered by Vipel F085 CONCLUSIONS a) Vipel F08 has a styrene content of 5% and a heat distortion temperature of 0 F (5 C) b) The Vipel F08 viscosity, gel and cure properties are typical of Vipel F085 and Vipel F00 resins; thus, there are no fabrication issues c) High temperature cast and laminate tensile properties of Vipel F08 are significantly higher than that of either Vipel F085 or Vipel F00 d) Both Vipel F08 and Vipel F085 are more resistant to methanol and toluene than Vipel F00 e) At the 9 month interval, Vipel F08 and Vipel F085 have lost less weight at 50 F (77 C) than Vipel F00 FUTURE DEVELOPMENTS a) Twelve month 50 F (77 C) air exposure testing will be completed b) Nine and twelve month corrosion resistance of Vipel F08, Vipel F085 and Vipel F00 will be compared

3 BIOGRAPHICAL NOTE Bruce Curry is a product leader for AOC, LLC He has an Honors Bachelor of Science degree from the University of Waterloo, Waterloo, Canada Figure CASTING PREPARATION CATALYST AND CURE SCHEDULE QUANTITY AND TIME Catalyst system Benzoyl Peroxide (BPO), % 0 Cure schedule 0 F (0 C), hours F (9 C), hours 240 F ( C), hours 280 F (8 C), hours 20 F (0 C), hours 2 Figure 2 RESIN LIQUID PROPERTIES PROPERTY F00 F085 F08 77 F (25 C) Brookfield viscosity, spindle 20 rpm, cps Styrene content,% 9 5 Gel time with 0% cobalt, 005% DMA and 20% CHP (90% active), minutes Gel to peak exotherm, minutes 5 Peak exotherm, F( C) 47 (75) 84 (95) 90 (989) Specific gravity

4 Figure Laminate preparation Catalyst Promoters: DETAILS COMPOSITE CURE RATE F00 F085 F08 Cobalt (%),% DMA,% CHP content on the resin, % Construction Plies of 5 oz per square foot (450 grams per square meter) chopped strand mat Glass content, % Cure progression Gel time, minutes Time to tack free after gel, minutes Shore D Hardness after 2 hours after gel Barcol Hardness (94) after 24 hours Barcol Hardness (94) after 72 hours Figure 4 CAST MECHANICAL PROPERTIES at 25 C PROPERTY F00 F085 F08 Tensile strength, psi (MPa) 2,800(88),200(77) 0,000(9) Tensile modulus, psi (GPa) 40,000(2) 540,000(7) 550,000(8) Elongation, % 2 24 Flexural strength, psi (MPa) 22,000(5) 2,500(48),800() Flexural modulus, psi (GPa) 500,000(5) 540,000(7) 20,000(4) Heat distortion temperature, F ( C) 248 (20) 00 (489) 0(5) Barcol Hardness (94) Specific gravity 4 5

5 Figure 5 CAST TENSILE STRENGTH WITH INCREASING TEMPERATURE % RETENTION (5) 250 (2) 00 (489) TEMPERATURE, F ( C) 50 (77) Vipel F00 Vipel F085 Vipel F08 Figure CAST TENSILE MODULUS WITH INCREASING TEMPERATURE % RETENTION (5) 250 (2) 00 (489) 50 (77) Vipel F00 Vipel F085 Vipel F08 TEMPERATURE, F( C)

6 Figure 7 ASME RTP- LAMINATE TENSILE STRENGTH WITH INCREASING TEMPERATURE 00 % RETENTION (5) 250 (2) 00 (489) 50 (77) Vipel F00 Vipel F085 Vipel F08 TEMPERATURE, F ( C) Figure 8 % RETENTION ASME RTP- LAMINATE TENSILE MODULUS WITH INCREASING TEMPERATURE (5) 250 (2) 00 (489) TEMPERATURE, F ( C) Vipel F00 Vipel F085 Vipel F08

7 Figure 9 ASTM C 58 LAMINATES MADE WITH F08 AND EXPOSED TO TOLUENE AT 00 F (78 C) Flexural Strength, psi (MPa) 2,00 () 2,000 (59) 24,00 (70) 25,200 (74) % Retention Flexural Modulus, psi (GPa),20,000 (772),090,000 (75),080,000 (745),90,000 (82) % Retention Figure 0 Barcol Hardness % Retention 7 9 Weight (g) - original Weight (g) - exposed % weight change ASTM C 58 LAMINATES MADE WITH F085 AND EXPOSED TO TOLUENE AT 00 F (78 C) Flexural Strength, psi (MPa) 2,200 (0) 24,00 (8) 25,00 (77) 2,400 (48) % Retention Flexural Modulus, psi (GPa),050,000 (724),20,000 (772),0,000 (80),090,000 (752) % Retention Barcol Hardness % Retention Weight (g) - original Weight (g) - exposed

8 Figure ASTM C 58 LAMINATES MADE WITH F00 AND EXPOSED TO TOLUENE AT 00 F (78 C) Flexural Strength, psi (MPa) 29,900 (20) 5,400 (2) 0,200 (208) 20,00 (42) % Retention Flexural Modulus, psi (GPa),20,000 (84),20,000 (772) 870,000 (0) 80,000 (49) 4 Figure 2 % Retention Barcol Hardness % Retention Weight (g) - original Weight (g) - exposed % weight change ASTM C 58 LAMINATES MADE WITH F08 AND EXPOSED TO METHANOL AT 00 F (78 C) Flexural Strength, psi (MPa) 2,00 () 24,00 (70) 28,200 (94) 9,900 (7) % Retention Flexural Modulus, psi (GPa),20,000 (827) 880,000 (07) 90,000 (4) 720,000 (49) % Retention Barcol Hardness % Retention Weight (g) - original Weight (g) - exposed % weight change

9 Figure ASTM C 58 LAMINATES MADE WITH Vipel F085 AND EXPOSED TO METHANOL AT 00 F (78 C) 2 4 Flexural Strength, psi 2,200 (0) 24,00 (70) 9,700 () 8,00 (28) % Retention Flexural Modulus, psi,050,000 (GPa) (724) 780,000 (58) 720,000 (49) 750,000 (57) % Retention Barcol Hardness % Retention 55 5 Weight (g) - original Weight (g) - exposed % weight change Figure 4 Vipel F00 ASTM C 58 LAMINATES MADE WITH F00 AND EXPOSED TO METHANOL AT 00 F (78 C) Flexural Strength, psi (MPa) 29,900 (20) 20,400 (4) 8,500 (28) 20,00 (9) % Retention Flexural Modulus, psi (GPa),20,000 (84) 790,000 (545) 50,000 (448) 750,000 (57) % Retention Barcol Hardness % Retention Weight (g) - original Weight (g) - exposed % weight change

10 Figure 5 STM C 58 LAMINATES MADE WITH F08 AND EXPOSED TO 50 F (77 C) AND TESTED AT AMBIENT TEMPERATURE Flexural Strength, psi 2,00 () 2,400 (82) 2,900 (5) 28,00 (94) 2,200 (8) % Retention Flexural Modulus, psi,20,000,20,000,40,000,00,000,00,000 (GPa) (772) (772) (78) (89) (70) % Retention Barcol Hardness % Retention Weight (g) - original Weight (g) % weight change Figure ASTM C 58 LAMINATES MADE WITH Vipel F085 AND EXPOSED TO 50 F (77 C) AND TESTED AT AMBIENT TEMPERATURE 2 4 Flexural Strength, psi 2,000 (MPa) 2,200 (0) 2,400 () 2,500 (48) 2,00 (80) (59) % Retention Flexural Modulus, psi,00,000,00, ,000,20,000 90,000 (GPa) (758) (70) (7) (772) (27) % Retention Barcol Hardness % Retention Weight (g) - original Weight (g) % weight change

11 Figure ASTM C 58 LAMINATES MADE WITH F00 AND EXPOSED TO 50 F (77 C) AND TESTED AT AMBIENT TEMPERATURE 9 Flexural Strength, psi 29,00,500 (MPa) 29,900 (20) 2,000 (90) (204) 2,900 (227) (252) % Retention Flexural Modulus, psi,200,000,80,000,0,00 (GPa),20,000 (84),0,000 (779) (827) (952) 0 (885) % Retention Barcol Hardness % Retention 5 40 Weight (g) - original Weight (g) - exposed % weight change