Neat Thermoplastic Resins Properties 13 concentration of oxygen in a test atmosphere adequate to sustain continued burning of the test specimen for a specified period of time or until a specifled amount of material is consumed" 1561.The normal atmosphere contains 22%oxygen.All thermoplastics listed in Table 3 have L.O.I.values higher than the absolute minimum (28%)required to qualify the polymer "self- extinguishing"as per ASTM-D2863 (56].Hoescht Celauese's polyberizinidazole(PBI)has a very high L.O.I.value of 58.Although it gives an indication of the flammability of the polymer.it is not the only criteria to observe when choosing a fire resistant material:ignition temperature. burning time,tendency to drip,smoke emission and safety of the combustion products,for example are also important considerations. 2.2.2 Thermal Properties Thermal properties including glass transition temperature (Tg).melting temperature (Tm).processing temperature (Tp).heat deflection temperature (HDT)and continuous use service temperature (Ts)are presented in Table 4 while coefficients of thermal expansion (C.T.E.)are presented in Table 5.Included in Table 4 is the morphology of the polymers.i.e. amorphous or semi-crystalline.More detalled information on the morphological factors and the effects of morphology on physical properties of thermoplastic composites is given in Chapter 3. The performance of thermoplastic composites in high temperature environments depends on the Tg of the polymer matrix and its morphology [74].Below Tg.a polymer,either amorphous or scmi-crystallinc,is in a glassy state while above Tg.the material softens as the temperature increases and the material becomes rubbery.As shown in Figure 2.when heating a semi-crystalline polymer above Tg.the amorphous regions of the polymer can flow plastically and therefore heating is accompanied by a reduction in the polymer stiffness which may occur over a broader range of temperatures than that shown in the schematic of Figure 2 [741.A 100% crystalline polymer would eliminate the Tg process and replace it with the melting process.but this excessive crystallization would impair the ductility of the resin [75].At temperatures between Tg and Tm the semi-crystalline polymer consists of rigid crystalline regions dispersed in a soft amorphous matrix,so that the polymer is flexible.The properties of the semi- crystalllne thermoplastics are then significantly reduced,but to a lesser extent than in amorphous thermoplastics:they retain a portion of their load-bearing properties,but not above the melting temperature (Tm).Amorphous thermoplastics do not have a true melting temperature as melting is the disassociation of the crystalline structure [76.77].but they go through a glass transition.Above Tg.amorphous thermoplastics exhibit substantial loss of their mechanical properties.According to Cogwell's practical experience (74].the long-term service temperature of the composite is 25-30C below the Tg of the matrix;hence continuous use service temperature (Ts)for thermoplastics as reported in Table 4 from different sources
Neat Thermoplastic Resins Properties 13 concentration of oxygen in a test atmosphere adequate to sustain continued burning of the test specimen for a specified period of time or until a specified amount of material is consumed’ 1561. The normal atmosphere contains 22% oxygen. All thermoplastics listed in Table 3 have L.O.I. values higher than the absolute minimum (28%) required to quality the polymer “selfextinguishing” as per ASTM-D2863 (561. Hoescht Celanese’s polybenzimidazole (PBI) has a very high L.O.I. value of 58. Although it gives an indication of the flammability of the polymer, it is not the only criteria to observe when choosing a fire resistant material; ignition temperature, burning time, tendency to drip, smoke emission and safety of the combustion products, for example are also important considerations. 2.2.2 Thermal Properties Thermal properties including glass transition temperature (Tg), melting temperature (Tm). processing temperature (Tp). heat deflection temperature (HDT) and continuous use service temperature (Ts) are presented in Table 4 while coefficients of thermal expansion (C.T.E.) are presented in Table 5. Included in Table 4 is the morphology of the polymers, i.e. amorphous or semi-crystalline. More detailed information on the morphological factors and the effects of morphology on physical properties of thermoplastic composites is given in Chapter 3. The performance of thermoplastic composites in high temperature environments depends on the Tg of the polymer matrix and its morphology 1741. Below Tg. a polymer, either amorphous or semi-crystalline, is in a glassy state while above Tg. the material softens as the temperature increases and the material becomes rubbery. As shown in Figure 2, when heating a semi-crystalline polymer above Tg. the amorphous regions of the polymer can flow plastically and therefore heating is accompanied by a reduction in the polymer stiffness which may occur over a broader range of temperatures than that shown in the schematic of Figure 2 [74]. A lOO?/ crystalline polymer would elhninate the Tg process and replace it with the melting process, but this excessive crystallization would impair the ductility of the resin [75]. At temperatures between Tg and Tm the semi-crystalline polymer consists of rigid crystalline regions dispersed in a soft amorphous matrix, so that the polymer is flexible. The properties of the semicrystalline thermoplastics are then significantly reduced, but to a lesser extent than in amorphous thermoplastics; they retain a portion of their load-bearing properties. but not above the melting temperature (Tm). Amorphous thermoplastics do not have a true melting temperature as melting is the disassociation of the crystalline structure (76, 771. but they go through a glass transition. Above Tg. amorphous thermoplastics exhibit substantial loss of their mechanical properties. According to Cogwell’s practical experience [74]. the long-term service temperature of the composite is 25 - 30” C below the Tg of the matrix: hence continuous use service temperature (Ts) for thermoplastics as reported in Table 4 from different sources
14 High Performance Thermoplastic Resins and Their Composites TABLE 4.Thermal Properties of High-Performance Neat Thermoplastic Resins Resin Morphology Tg (C) Tm (C) Tp (C) HDT (C)1 Ts (C) Reference Victrex PEEK 143 343 370-400 152 1 143 334 350-380 160 250 21 145 335 200 58 143 334 22,59 334 370-400 250 60 144 340 12 144 340 380 2 Victrex PEK C 165 365 165 250 162 373 385-410 186 260 2 PEKK 156 338 12 156 360-370 6 250 156 338 370 2 Ultrapek O U 173 374 64 Kadel 63 340 160 23 Ryton PPS 85 285 330 135 24 C 85 285 25-30,65 90 290 315-340 115 200-240 1 85 285 343 2 Ryton PAS-2 A 215 315-343 28-30 215 325-330 198 1 218 66 222 343 215 330 2 Ryton S PPSS 218 343 J-2 156 290-305 154 1 160 290-305 138 32 156 300 Torlon 274 33 278 3 275 330-400 274 200 220 22 288 350 2 K-Polymer 251 340-400 250 360 35 251 360 232 34 250 350 N-Polymer 385-390 36,67,68 A 340.370 370 37,38 360 350-400 1 A 350 375 2 Eymyd U-25 A 249 343 39,69 Eymyd U-35 432 。。0 427 69 Eymvd U.55 A 288 (continued)
Neat Thermoplastic Resins Properties 15 TABLE 4.Thermal Properties of High-Performance Neat Thermoplastic Resins(cont'd) Resin Morphology Tg (C) TmC)Tp) HDT (C)Ts (C) Reference Ultem 219-234 200-216 40 A 230 41 217 340-400 200 170 1 210 340-380 200 32 A 217 343 2 Cypac 230 304-343 41 A 217-275 350-385 42 A 230-275 302-357 180 43 Larc-TPI (MTC) c 261 270-340 44 264 275,325 343 3 New-TPI A 250 238-260 70 271 204 63 Durimid A 255-256 340 40,45 320.350 45,71 Udel 185 174 160 14 343-399 174 23 190 300 3 Radel-A A 217 204 180 14 345-388 204 23 220 330 3 Radel-R 220 204 23 14 Victrex PES A 220 203 180 14 230 315-370 203 180 1 203 180 48 260 330 2 Xydar 421 360-430 355 240 1 358 360-398 337 50 421 355 51 358-364 332.347 52 Vectra 280 180-200 53 300-340 16 280-285300-340 15 PBI A 430 24 427 435 17 430 72 470 18 PPQ 290 350-400 1 9 207.390 ””中 14 288 400 260 19 3501-6·÷· 206 177 5245-C 226 177 54 C crystalline.A amorphous Heat distortion temperature at 1.82 MPa.ASTM D648 First generalion epoxy
Neat Thermoplastic Resins Properties 15 TABLE 4. Thermal Properties of High-Performance Neat Thermoplastic Resins (cont’d) Resin Ultem Cypac Larc-TPI (MTC) New-TPI Durimid Udel Radel-A Radel-R Victrex PES Xydar Vectra PBI 290 A 07-39c 288 206 226 * C = crystalline \ = amorphous ** Heat distortion temperature at 1.82 MPa. ASTM D64a *** First generation epoxy 1 177 I Jlorphology ’ Tg Tm (“C) Tp (“C) HDT (“C)’ Ts Reference I1 9-23r 230 217 210 217 230 :17-271 :30-27: 261 264 250 271 55-256 _ _ - 200-216 _ - - _ _ - 340-400 200 _ - - 340-380 200 _ _ - 343 _ _ _ 304-343 _ _ _ 350-385 _ _ _ 302-357 :70-340 ‘75-325 343 _ - - 238-260 170 ia0 204 _ _ _ 340 320-350 ___ 174 343-399 174 300 _ _ _ 204 345-388 204 330 40 41 1 32 2 41 42 43 44 3 70 63 40, 45 45, 71 14 23 3 14 23 3 23 14 14 1 48 2 1 50 51 52 53 16 15 24 17 72 la 1 14 19 1 54 A 1 a5 190 217 220 220 220 230 260 430 427 204 _ _ _ _ _ _ 203 _ _ _ 315-370 203 203 I 330 I 421 /360-4301 355 160 ia0 180 la0 la0 240 260
16 High Performance Thermoplastic Resins and Their Composites TABLE 5.Coefficient of Thermal Expansion(C.T.E.)of High-Performance Neat Thermoplastic Resins Resin C.T.E.(x10-5/℃) Temperature Range (C) Reference Victrex PEEK 47 21 108 >150 21 Victrex PEK 57,69 20·150,150·200 22 79,84 200·250.250.300 22 Ryton PPS 59.7 -50 73 04,0 23 73 108.9 150 73 Torlon 35 23·149 33 N-Polymer 90 23-323 67 PEI Ultem 52·56 20-150 40 Eymyd U-25 44 N/A 39 Laro TPI (MTC) 24-33 20-200 44 New TPI 50·55 N/A 70 Durimid 35 20·240 45.46 Udei 51 N/A 14 RadelA 49 N/A 14 Radel R 55 N/A 14 Victrex PES 55 N/A 14 Vectra ·5 parallel to flow 53 .50·200 40.75 transverse to flow 53 -50·200 PBI 23 24·149 17 32 200·300 17
16 High Performance Thermoplastic Resins and Their Composites TABLE 5. Coefficient of Thermal Expansion (C.T.E.) of High-Performance Neat Thermoplastic Resins Radel A 49 N/A 14 Radel R 55 N/A 14 Victrex PES 55 N/A 14 Vectra -5 parallel lo flow 53 -50 - 200 40 - 75 transverse to flow 53 -50 - 200 PBI 23 24 - 149 17 32 200 - 300 17
Neat Thermoplastic Resins Properties 17 MODULUS Tg Tm Crystalline Amorphous iMelting Point TEMPERATURE FIGURE 2.Semi-Crystalline Thermoplastic Polymers Retain Part of Their Properties above Tg [75]
Neat Thermoplastic Resins Properties 17 MODULUS 1 Tg Tm Crystalline I --_____------w---w-\ \ I 4 I t I I I I I I Amorphous ! Melting Point c TEMPERATURE FIGURE 2. Semi-Crystalline Thermoplastic Polymers Retain Part of Their Properties above Tg [75]