988 V.Sharma.P.P.Kundu Prog.Polym.Sci.31 (2006)983-1008 Table 3 Original composition (wt%) Gelation time (s) Yield(%)of cross linked polymer after extraction Triglyceride oil Comonomers Initiators 45%LSS 32%ST+15%DVB 5%SG-I+3%BFE 3.0×10 45%L5s 29ST+159%DvE 30×10 5%NF0t3% 3.0× 45%CLS 32%ST+15%DVB 5%NFO+3%BFE 6.6×10 45%CLS 32%ST+15%DC 39%6NF0+39%BFE 2.1×10 Reproduced with the permission from J Appl Polym Sci 2001:80:662 John Wiley and Sons,Inc.[11] TtAMA.TGA.andSotitetiacioareifactcanplkspparodbyeopo ocrization of sovbcan oil and divinvlbenzcne in the presence of modified initiator Polymer sample TC) Structure (wt% TGA (C) Cross-linked Free oil Ine.oil To Tso 760 16 SOY6o-DVB25-NFOI-BFES) IS-DVB NFOIO-BFES) 3 0 LSSSS-DVB30-(NFO10-BFE5) 835 70507007 080 CLS50-DVB3S-NFOI-BEES 13578603244 970245 CLS40-DVBNFO-BEES 78 12 Reproduced with the pe rmission from Polymer 2001:42:1573 C Elsevier Science Ltd..I10L E c二Young's m s at room temperature. .Here SOY re noil,CLS- -No induces reduction in the glass transition tempera- at temperatures dependent on the oil,e.g..68C for ture,stiflness and modulus. regula soybean oil,61C for low saturated soybean The variation of the storage modulus(F)and loss oil and 76C for conjugate d low saturated soybean temperature is s hown in Figs. oil.This single loss pea ind cates that the polymer ers prepare omogeneous phase the gated low saturated soybean oil.In Fig 5.the and stor moduli polymers from these oils exhibited a single loss peak prepared from soybean oi
induces reduction in the glass transition temperature, stiffness and modulus. The variation of the storage modulus (E0 ) and loss factor (tan d) with temperature is shown in Figs. 4 and 5, respectively, for several copolymers prepared from regular soybean oil. In Fig. 4, E0 is minimum for regular soybean oil and maximum for conjugated low saturated soybean oil. In Fig. 5, the polymers from these oils exhibited a single loss peak at temperatures dependent on the oil, e.g., 68 1C for regular soybean oil, 61 1C for low saturated soybean oil and 76 1C for conjugated low saturated soybean oil. This single loss peak indicates that the polymers had a homogeneous phase. From these results, it is clear that in all soybean oils used, the conjugated low saturated soybean oil gave the highest crosslinking density, glass transition and storage moduli. Copolymers were also prepared from soybean oil ARTICLE IN PRESS Table 4 The DMA, TGA, and Soxhlet extraction results for the samples prepared by copolymerization of soybean oil and divinylbenzene in the presence of modified initiator Polymer samplea Eroom(Pa) 108 ne(mol/m3 ) 103 Tg(1C) Structure (wt%) TGA (1C) a1 a2 Cross-linked Free oil Inc. oilb T10 T50 SOY60-DVB35-BFE5 4.0 7.60 27 — 69 31 29 415 490 SOY50-DVB35-(NFO10-BFE5) 5.0 11.6 70 10 77 23 37 425 491 SOY55-DVB30-(NFO10-BFE5) 2.5 6.51 15 5 75 25 40 380 475 SOY60-DVB25-(NFO10-BFE5) 1.7 4.18 20 0 73 27 43 360 470 LSS60-DVB35-BFE5 6.0 10.4 37 - 82 18 42 423 485 LSS50-DVB35-(NFO10-BFE5) 7.0 13.0 70 0 84 16 44 425 486 LSS55-DVB30-(NFO10-BFE5) 3.8 8.35 30 8 80 20 45 405 486 LSS60-DVB25-(NFO10-BFE5) 1.9 4.18 17 0 77 23 47 395 485 CLS50-DVB35-(NFO10-BFE5) 12 18.9 90 - 88 22 48 440 485 CLS55-DVB30-(NFO10-BFE5) 10 11.4 80 - 86 14 51 436 486 CLS60-DVB25-(NFO10-BFE5) 7.8 7.21 68 - 86 14 56 433 483 Reproduced with the permission from Polymer 2001; 42: 1573 r Elsevier Science Ltd., [10]. Eroom ¼ Young’s modulus at room temperature. ne ¼ Cross-linking density. a Here SOY represents regular soybean oil, LSS—Low saturated soybean oil, CLS—conjugated low saturated soybean Oil, DVB— divinylbenzene, NFO—Norway Pronova fish oil ethyl ester and BFE —boron trifluoride diethyl etherate. The numerals, such as SOY60 represents 60 wt% of soybean oil. b Wt% of oil incorporated into the cross-linked network. Table 3 The results from copolymerization of different soybean oils using different modified initiator system with styrene and divinylbenzene, norbornadiene or dicyclopentadiene Original composition (wt%) Gelation time (s) Yield (%) of cross linked polymer after extraction Triglyceride oil Comonomers Initiators 45% LSS 32%ST+15%DVB 5%SG-I+3%BFE 3.0 102 83 45% LSS 32%ST+15%DVB 5%SG-II+3%BFE 3.0 102 82 45% LSS 32%ST+15%DVB 5%SG-III+3%BFE 3.0 102 83 45% LSS 32%ST+15%DVB 5%NFO+3%BFE 3.0 102 84 45% SOY 32%ST+15%DVB 5%NFO+3%BFE 2.4 102 80 45% LSS 32%ST+15%DVB 5%NFO+3%BFE 3.0 102 84 45% CLS 32%ST+15%DVB 5%NFO+3%BFE 6.6 102 92 45% CLS 32%ST+15%DVB 5%NFO+3%BFE 6.6 102 92 45% CLS 32%ST+15%NBD 5%NFO+3%BFE 3.5 103 89 45% CLS 32%ST+15%DCP 5%NFO+3%BFE 2.1 105 80 Reproduced with the permission from J Appl Polym Sci 2001; 80: 662 r John Wiley and Sons, Inc. [11]. 988 V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008
V.Sharma.P.P.Kundu Prog.Polym.Scl.31(2006)983-100 989 Polymer sample 7(g(molm×102 E(mpa)(mpa)(%)Toughness (mpa) 53 CLS45st32-DVB15-(NFO5-BFE3) 225 40.5 Reproduced with the permision from Polym Sci:Part B:Polym 62John Wiley and Sons,Ine.[ 1.E+10- SOY45-ST32-DVBIS-(NFO5-BFE 1.E+09 CLS45-ST32-DVBIS-(NFOS-BFES 1E+08 1 L.E40 05 1.E+06 土然電 1.E+05 1 125 are (C) 35155254565510s125 Temperature Fig.4.The temperature dependence of the storage modulus (E) regular soybean oil (SOY) enzene (DVB).using vay fis () Inc.[12. and divinylbenzene,using boron trifluoride diethyl low saturated soybean oil polymers show a yield etherate,resulting in heterogeneous polymeric point. materials [10]. The tensile fracture surface of polymer samples The tensile properties of several soybean oil (with 35 weight conjugated low saturated stomers har soybean oil)was observe d under a se polymers ope and n very similar SEM r the tensile strength fracture surface nd the mist fracture hreak decreases with an increase in the degree of surface are shown in Figs.7(a)and 7(b),respec cross-linking.At lower strain(<10%),the increase tively.for one sample. in stress is rapid,while at higher strain(0%),the The results for damping properties of several regular and low saturated soybean oil polymers soybean oils over a broad range of temperature and exhibit a slow increase in the stress.The conjugated frequency are reported in Table 6 [14].The high
and divinylbenzene, using boron trifluoride diethyl etherate, resulting in heterogeneous polymeric materials [10]. The tensile properties of several soybean oil polymers ranging from elastomers to hard, ductile and relatively brittle polymers are shown in Fig. 6 [13]. Generally, it is observed that the ultimate tensile strength increases and the elongation at break decreases with an increase in the degree of cross-linking. At lower strain (o10%), the increase in stress is rapid, while at higher strain (410%), the regular and low saturated soybean oil polymers exhibit a slow increase in the stress. The conjugated low saturated soybean oil polymers show a yield point. The tensile fracture surface of polymer samples (with 35 weight % conjugated low saturated soybean oil) was observed under a scanning electron microscope and shown to be very similar to those of epoxies [Fig. 7]. The SEM micrograph of the fracture surface and the mist region of the fractured surface are shown in Figs. 7(a) and 7(b), respectively, for one sample. The results for damping properties of several soybean oils over a broad range of temperature and frequency are reported in Table 6 [14]. The high ARTICLE IN PRESS Table 5 The tensile test results for various soybean oils Polymer sample Tg (1C) ne (mol/m3 ) 102 E (mpa) sb (mpa) eb (%) Toughness (mpa) SOY45st32-DVB15-(NFO5-BFE3) 68 1.8 71 4.1 57.1 1.67 LSS45st32-DVB15-(NFO5-BFE3) 61 5.3 90 6.0 64.1 2.86 CLS45st32-DVB15-(NFO5-BFE3) 76 22 225 11.5 40.5 4.00 Reproduced with the permission from J Polym Sci: Part B: Polym Phys 2000; 39: 62 r John Wiley and Sons, Inc. [13]. Tg ¼ Glass transition temperature. ne ¼ Cross-linking density. E ¼ Young’s modulus. sb ¼ Ultimate tensile strength. eb ¼ Elongation at break. SOY45-ST32-DVB15-(NFO5-BFE3) LSS45-ST32-DVB15-(NFO5-BFE3) CLS45-ST32-DVB15-(NFO5-BFE3) Temperature (°C) 1. E+10 1. E+09 1. E+08 1. E+07 1. E+06 1. E+05 Storage Modulus (Pa) -35 -15 5 25 45 85 105 12 65 5 Fig. 4. The temperature dependence of the storage modulus (E0 ) on the copolymers prepared from regular soybean oil (SOY), Lowsat soy oil (LSS) and conjugated Lowsat soy oil (CLS) with styrene (ST) and divinylbenzene (DVB), using Norway fish oil modified initiator. Reprinted with permission from J Polym Sci: Part B: Polym Phys 2000; 38: 2726 r John Wiley and Sons, Inc. [12]. -35 -15 5 25 45 85 105 125 Temperature Tan δ SOY45-ST32-DVB15-(NFO5-BFE3) 0 0.5 1 1.5 CLS45-ST32-DVB15-(NFO5-BFE3) LLS45-ST32-DVB15-(NFO5-BFE3) 65 Fig. 5. The temperature dependence of the loss modulus (tan d) for the copolymers prepared from regular soybean oil (SOY), Lowsat soy oil (LSS) and conjugated Lowsat soy oil (CLS) with styrene (ST) and divinylbenzene (DVB), using Norway fish oil modified initiator. Reprinted with permission from J Polym Sci: Part B: Polym Phys 2000; 38: 2727 r John Wiley and Sons, Inc. [12]. V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008 989
990 V.Sharma.P.P.Kundu Prog.Polym.Sci.31 (2006)983-1008 SOY45-ST32-DVBIS-(NFOS-BFES ·X @ 0 40 60 Strain(%) Poly damping intensities are ascribed to the contribution d sur from the large number of ester groups directly e-divinylbenzene he samp e and the mist region of the Polym Phys 2000:39:Wiley and Sons.Inc.3 in e e w al cro The three s ovbean oil p olymers showed the same glass transition temperature.but differ in the value of the loss tangent maxima.The broad damping have applications in civil construction.mechanics e T o and manufacturing.electronics and communica induced on cross-linking. However. tions,printing and packaging.medical equipment. also reduced the damping intensities by restricting recreation and sports,and household items the polymer segm the homogene mec tha anica h mers s at relatively high ten tures [16-191.Shape olymers to form interpenetrating networks (IPN)with a CItiCtophasaeicriblephaeanda fixed phase.The reversible phase refers to the polymer matrix,which has a glass transition facilitated by temperature (T)or a melting temperature (Tm) rom the forma well above the applicatio rather than by the segmenta phase or physi polymer th le at a temp mryrefer to the the sha memory olymer achieves a rubbery elastic state in
damping intensities are ascribed to the contribution from the large number of ester groups directly attached to the soybean oil–styrene–divinylbenzene copolymer chains. The variation in the glass transition temperature with cross-linking density is shown in Fig. 8 for several soybean oil polymers. The three soybean oil polymers showed the same glass transition temperature, but differ in the value of the loss tangent maxima. The broad damping regions were attributed to segmental inhomogeneity induced on cross-linking. However, cross-linking also reduced the damping intensities by restricting the polymer segmental motions of the homogeneous polymeric materials. Thus, it is expected that efficient damping materials (for sound and vibrational applications) would result on the chemical or physical combination of two or more structurally dissimilar soybean oil-based polymers to form interpenetrating networks (IPN) with a phase separated morphology. In such a case, broad damping regions would be facilitated by phase microheterogeneity resulting from the formation of IPNs, rather than by the segmental inhomogeneity [14]. Some soybean oil polymers prepared by cationic copolymerization show a good shape-memory effect [15]. Shape-memory refers to the ability of some materials to remember a specific shape on demand, even after very severe deformation. Such materials have applications in civil construction, mechanics and manufacturing, electronics and communications, printing and packaging, medical equipment, recreation and sports, and household items. A shape-memory polymer exhibits mechanical behavior that includes fixing the deformation of the plastics at room temperature and recovering the deformation as elastomers at relatively high temperatures [16–19]. Shape-memory polymers basically consist of two phases: a reversible phase and a fixed phase. The reversible phase refers to the polymer matrix, which has a glass transition temperature (Tg) or a melting temperature (Tm) well above the application temperature. The fixed phase is composed of either chemical or physical cross-links that are relatively stable at a temperature higher than the Tg or Tm of the reversible phase. At a temperature above Tg or Tm, the shapememory polymer achieves a rubbery elastic state in ARTICLE IN PRESS 0 20 40 60 80 Strain (%) 0 4 8 12 Stress (MPa) SOY45-ST32-DVB15-(NFO5-BFE3) CLS45-ST32-DVB15-(NFO5-BFE3) LLS45-ST32-DVB15-(NFO5-BFE3) Fig. 6. The tensile stress-strain curves from three soybean oil polymers i.e. regular (SOY), low saturated (LSS) and conjugated low saturated (CLS) soybean oil polymers for same percentage of oil and comonomers styrene (ST) and divinylbenzene (DVB). Reprinted with permission from J Polym Sci: Part B: Polym Phys 2000; 39: 63 r John Wiley and Sons, Inc. [13]. Fig. 7. The SEM micrograph of sample CLS35ST39-DVB18- (NFO5-BFE3) highlighting the mechanically fractured surface of the sample and the mist region of the mechanically fractured surface. Reprinted with permission from J Polym Sci: Part B: Polym Phys 2000; 39: 75 r John Wiley and Sons, Inc. [13]. 990 V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008
V.Sharma.P.P.Kundu Prog.Polym.Scl.31(2006)983-100 991 for the dampin perti of th oord Polymer sample TC)ve(mol/m)(tan (tan AT at tan 6>0.3 (C)TA (K)Half-width (C) SYADVBISNTO-E 46 SO39-DV S-NNFO .0x10 6 _SS45st32-DVBl5-(NFO5-BFE3) 0.8 03 19-9778 CLS35st39-DVBI8-(NFOS-BFE3 4×10 0 007 58668 CLSS-DVB1ANF8-BFE周 5127454 Reproduced with permission from Polymers for Advanced Technologies 2002:13:439.441 e John Wiley and Sons.Ltd..I41. Glass n te mperature )=Loss ngent maxima 120 the strong relaxations of the oriented polymer chains between the cross-links. Table 7 shows the shape-memory properties of several soybean oil polymers.It is observed that the type of soybean oil greatly affects the shape 80 hese polymers (e.g.,se rs fr ehertdieenabiyat than T.(D value).All of ther ric materials showve()ed deformationpo reheating to T:plus 50C. 10 The time for gelation and vitrification of various soybean oil polymer systems has been investigated CLS45-(ST+DVB)47-(NFO5-BFE3) fully cured t rst mac 10 100 1000 10000 100000 v.(mol/m dynamic resultin 一dma"anical benavoro curing conditions.However,varying the curing time at low and high temperatures did affect the structural c characteristics of the polymer backbone. which it can be easily deformed by an external force affecting the shape-memory and tensile mechanical n temperatur properties. hermal time-temperatur frozen micr mation ( am,developed to hardened reversible phase effectively re the s of the recovery resulting from the tendeney of the ordered chains to return to a more random state,but the at which the system gels and vitrifies simulta deformed shape readily returns to its original shape neously)and T(maximum T of fully cured upon heating above T or Tm.The driving force for system),where gelation precedes vitrification,are of the shape recovery is primarily entropy,especially practical importance.It was observed that gelation
which it can be easily deformed by an external force. When the polymer is cooled to room temperature, the deformation is fixed due to the frozen micro Brownian motion of the reversible phase. The hardened reversible phase effectively resists elastic recovery resulting from the tendency of the ordered chains to return to a more random state, but the deformed shape readily returns to its original shape upon heating above Tg or Tm. The driving force for the shape recovery is primarily entropy, especially the strong relaxations of the oriented polymer chains between the cross-links. Table 7 shows the shape-memory properties of several soybean oil polymers. It is observed that the type of soybean oil greatly affects the shapememory properties of these polymers (e.g., see No. 1–3). The polymers from reactive soybean oil show higher degree of fixed deformation (FD value) and a lower deformability at a temperature higher than Tg (D value). All of the polymeric materials show 100% recovery (R) of fixed deformation upon reheating to Tg plus 50 1C. The time for gelation and vitrification of various soybean oil polymer systems has been investigated over a range of isothermal curing temperatures [20]. All the fully cured thermosets were first made at room temperature and then subjected to post-curing at elevated temperatures. The thermal stability and dynamic mechanical behavior of the resulting thermosets were not particularly sensitive to the curing conditions. However, varying the curing time at low and high temperatures did affect the structural characteristics of the polymer backbone, affecting the shape-memory and tensile mechanical properties. The isothermal time–temperature–transformation (TTT) cure diagram, developed to study the epoxy systems [21–23], is a very useful tool for investigating the cure process of the soybean oil systems. The cure temperatures between Tg,gel, (Tg at which the system gels and vitrifies simultaneously) and TgN (maximum Tg of fully cured system), where gelation precedes vitrification, are of practical importance. It was observed that gelation ARTICLE IN PRESS υe (mol/m3) 10 100 1000 10000 100000 0 20 40 60 80 100 T g (°C) 120 SOY45-(ST+DVB) 47-(NFO5-BFE3) LSS45-(ST+DVB) 47-(NFO5-BFE3) CLS45-(ST+DVB) 47-(NFO5-BFE3) Fig. 8. The dependence of the glass transition temperature (Tg) on cross-linking density (ne) for different soybean oil polymers. Reprinted with permission from Polym Adv Technol 2002; 13: 444 r John Wiley and Sons, Ltd. [14]. Table 6 Results for the damping properties of the copolymers prepared from different soybean oils Polymer sample Tg(1C) ne(mol/m3 ) (tan d)max (tan d)rt DT at tan d40.3 (1C) TA (K) Half-width (1C) SOY35st39-DVB18-(NFO5-BFE3) 79 4.7 102 0.88 0.12 52–115 (63) 37.5 47 SOY45st32-DVB15-(NFO5-BFE3) 68 1.8 102 0.85 0.32 23–113 (90) 48.4 61 SOY55st25-DVB12-(NFO5-BFE3) 30 1.0 102 0.84 0.83 2–65 (67) 36.3 51 LSS35st39-DVB18-(NFO5-BFE3) 80 7.3 102 0.86 0.11 23–113 (90) 48.4 51 LSS45st32-DVB15-(NFO5-BFE3) 61 5.3 102 0.89 0.37 19–97 (78) 46.2 52 LSS55st25-DVB12-(NFO5-BFE3) 32 3.9 102 1.00 0.96 6–83 (89) 50.1 57 CLS35st39-DVB18-(NFO5-BFE3) 82 3.4 103 0.94 0.07 58–116 (58) 41.8 42 CLS45st32-DVB15-(NFO5-BFE3) 76 2.2 103 0.79 0.18 48–120 (72) 43.1 53 CLS55st25-DVB12-(NFO5-BFE3) 38 6.5 102 1.08 0.80 10–77 (67) 52.9 44 Reproduced with permission from Polymers for Advanced Technologies 2002; 13: 439,441 r John Wiley and Sons, Ltd., [14]. Tg ¼ Glass transition temperature. ne ¼ Cross-linking density. (tan d)max ¼ Loss tangent maxima. (tan d)rt ¼ Loss tangent at room temperature. TA ¼ tan d area. V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008 991