Polymers for Advanced Technologies  Volume 13, 2002. Pages: 436-449
 

NEW SOYBEAN OIL – STYRENE – DIVINYLBENZENE THERMOSETTING COPOLYMERS. IV. GOOD DAMPING PROPERTIES

Fengkui Li, Richard C. Larock *

Department of Chemistry, Iowa State University, Ames, IA 50011

^*Correspondence to Professor R. Larock, Department of Chemistry, Gilman 3709, Iowa State University, Ames, IA 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

soybean oil, cationic copolymerization, damping materials.

Abstract

New polymeric materials have been prepared by the cationic copolymerization of regular soybean oil, low saturation soybean oil, i.e. LoSatSoy oil, or conjugated LoSatSoy oil with styrene and divinylbenzene, norbornadiene or dicyclopentadiene initiated by boron trifluoride diethyl etherate (BF3*OEt2) or related modified initiators. The effects of the stoichiometry, the type of soybean oil and the alkene comonomer on the damping behavior of the resulting polymers have been investigated. The damping properties have been quantitatively evaluated by the loss tangent maximum (tan d)max, the temperature range DT for efficient damping (tan d > 0.3), and the integrals of the linear tan d versus temperature curves (tan d area, TA). These bulk materials are composed primarily of soybean oil-styrene-divinylbenzene random copolymers with considerable variability in the backbone compositions. The good damping properties of the soybean oil polymers are presumably determined by the presence of fatty acid ester side groups directly attached to the polymer backbone and the segmental heterogeneities resulting from crosslinking. In general, crosslinking reduces the (tan d)max and the TA values, but broadens the region of efficient damping (DT). Soybean oil polymeric materials with appropriate compositions and crosslink densities are capable of efficiently damping over a temperature region in excess of 110 oC and provide noise and vibration attenuation over broad temperature and frequency ranges.© 2001 John Wiley & Sons, Inc. Polymers for Advanced Technologies 00: 0000-0000, 2001

Journal of Applied Polymer Science  Volume 84, Issue 8, 2002. Pages: 1533-1543
 

NEW SOYBEAN OIL – STYRENE – DIVINYLBENZENE THERMOSETTING COPOLYMERS. V. SHAPE MEMORY EFFECT

Fengkui Li, Richard C. Larock *

Department of Chemistry, Iowa State University, Ames, IA 50011

^*Correspondence to Professor R. Larock, Department of Chemistry, Gilman 3709, Iowa State University, Ames, IA 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

soybean oil, cationic copolymerization, shape memory effect.

Abstract

A series of new shape memory polymers have been synthesized by the cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy oil), and/or conjugated LoSatSoy oil with styrene and divinylbenzene, norbornadiene or dicyclopentadiene initiated by boron trifluoride diethyl etherate (BF3*OEt2) or related modified initiators. The shape memory properties of the soybean oil polymers have been characterized by the deformability (D) of the materials at temperatures higher than their glass transition temperatures (Tg), the degree to which the deformation is subsequently fixed at ambient temperature (FD), and the final shape recovery (R) upon being reheated. It has been found that a Tg well above ambient temperature and a stable crosslinked network are two prerequisites for these soybean oil polymers to exhibit shape memory effects. Good shape memory materials with high D, FD and R values have been prepared by controlling the crosslink densities and the rigidity of the polymer backbones. The advantage of the soybean oil polymers lies in the high degree of chemical control one has over the shape memory characteristics. This makes these materials particularly promising in applications where shape memory properties are desirable.© 2001 John Wiley & Sons, Inc. J Appl Polym Sci 00: 0000-0000, 2001

ELSEVIER

Thermophysical and Mechanical Properties of Novel Polymers Prepared by the Cationic Copolymerization of Fish Oils, Styrene and Divinylbenzene
 

Fengkui Li, Annik Perrenoud, Richard C. Larock
Department of Chemsitry, Iowa State University, Ames, IA 50011, USA.

New polymeric materials have been prepared from the cationic copolymerization of fish oil ethyl ester (NFO), conjugated fish oil ethyl ester (CFO) or triglyceride fish oil (TFO) with styrene and divinylbenzene initiated by boron trifluoride diethyl etherate (BF₃oOEt₂). These materials are typical thermosetting polymers with crosslink densities ranging from 1.1 ¥ 10² to 2.5 ¥ 10³ mol/m³. The thermogravimetric analysis of the new fish oil polymers exhibits three distinct decomposition stages at 200-340 ^oC, 340-500 ^oC and > 500 ^oC, respectively, with the maximum weight loss rate at approximately 450 oC. Single glass-transition temperatures of Tg = 30-10^{9 o}C have been obtained for the fish oil polymers. As expected, these new polymeric materials exhibit tensile stress-strain behavior ranging from soft rubbers through ductile to relatively brittle plastics. The Young’s modulus (E) of these materials varies from 2 to 870 MPa, the ultimate tensile strength (sb) varies from 0.4 to 42.6 MPa, and the percent elongation at break (e_b) varies from 2% to 160%. The failure topography indicates typical fracture mechanisms of rigid thermosets, and the unique fibrillation on the fracture surface gives rise to relatively high mechanical properties for the corresponding NFO polymer. The new fish oil polymers not only exhibit thermophysical and mechanical properties comparable to petroleum-based rubbery materials and conventional plastics, but also possess more valuable properties, such as good damping and shape memory behavior, which most petroleum-based polymers do not possess, suggesting numerous, more promising applications of these novel fish oil-based polymeric materials.

Keywords:  fish oil, alkenes, cationic copolymerization, thermosets, dynamic mechanical behavior, damping, shape memory effect, tensile test
 

Journal of Applied Polymer Science  Volume 81, Issue 8, 2000. Pages: 2001-2012
 

SYNTHESIS OF THERMOSET PLASTICS BY THE LEWIS ACID-INITIATED COPOLYMERIZATION OF FISH OIL ETHYL ESTERS AND ALKENES

Dave Marks, Fengkui Li, Chad M. Pacha and Richard C. Larock *

Department of Chemistry, Iowa State University, Ames, IA 50011

^*Correspondence to Professor R. Larock, Department of Chemistry, Gilman 3709, Iowa State University, Ames, IA 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

Boron trifluoride diethyl etherate, Fish oil, Cationic polymerization, Thermosets.

Abstract

The Lewis acid-initiated cationic homopolymerization of Norway fish oil ethyl ester (NFO) or the corresponding conjugated fish oil (CFO) and their copolymerization with various alkene comonomers have been investigated. Among the Lewis acids employed, boron trifluoride diethyl etherate (BF3oOEt2 = BFE) has been found to be the most effective initiator for cationic polymerization of the NFO and CFO systems. The BFE-initiated homopolymerization of NFO generally results in low molecular weight viscous oils, while that of the CFO leads to a solid elastic gel with a gel time of more than 72 hours at room temperature. Copolymerization of the NFO or CFO with some alkene comonomers significantly facilitates gelation. The gel times are largely dependent upon the stoichiometry, the type of fish oil and the alkene comonomer. After post-curing at elevated temperatures, the cationic copolymerization affords polymers ranging from soft rubbery materials to rigid plastics. These NFO and CFO polymers are composed of highly crosslinked materials and a certain amount of free oils, and have been found to be fully cured thermosets. Generally, CFO polymers appear to be harder than the corresponding NFO polymers. However, the thermal properties of the bulk polymers are similar to each other, and their insoluble extracts exhibit much higher thermal stability than the bulk thermosets.© 2000 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2001-2012, 2001

^*Correspondence to Richard C. Larock, Department of Chemistry, Iowa State University, Ames, Iowa 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

Soybean oil, Cationic copolymerization, Thermosetting polymers, Tensile stress-strain behavior

Abstract

The tensile stress-strain behavior and fracture properties of some new soybean oil-based polymeric materials have been investigated at room temperature. These materials have been prepared by the cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy oil) or conjugated LoSatSoy oil with styrene and the diene comonomers divinylbenzene, norbornadiene or dicyclopentadiene in a process initiated by boron trifluoride diethyl etherate (BF3·OEt2) or related modified initiators. These new polymeric materials exhibit tensile stress-strain behavior ranging from soft rubbers through ductile to relatively brittle plastics. The YoungÕs moduli E of these polymers vary from 3 to 615 MPa, the ultimate tensile strengths sb from 0.3 to 21 MPa, and the elongation-to-breaks eb from 1.6 to 300%. These properties are obviously related to their crosslink densities ne. The conjugated LoSatSoy oil polymers have higher mechanical properties than the corresponding LoSatSoy oil and regular soybean oil polymers with the same stoichiometry. Some conjugated LoSatSoy oil polymers with appropriate stoichiometries show yielding behavior in the tensile test process. A variety of new polymer materials can thus be prepared by varying the stoichiometry, type of the soybean oil and the crosslinking agent. These soybean oil-based polymers possess mechanical properties comparable to those of commercially available rubbery materials and conventional plastics, and thus may serve as replacements in many applications. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 60-77, 2001

^*Correspondence to Richard C. Larock, Department of Chemistry, Iowa State University, Ames, Iowa 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

soybean oil; cationic copolymerization; thermosetting polymers; dynamic mechanical properties

Abstract

A variety of new polymeric materials ranging from soft rubbers to hard, tough, and brittle plastics were prepared from the cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy oil), or conjugated LoSatSoy oil with styrene and divinylbenzene initiated by boron trifluoride diethyl etherate (BF3 · OEt2) or related modified initiators. The relationship between the dynamic mechanical properties of the various polymers obtained and the stoichiometry, the types of soybean oils and crosslinking agents, and the different modified initiators was investigated. The room-temperature storage moduli ranged from 6 ? 106 to 2 ? 109 Pa, whereas the single glass-transition temperatures (Tg) varied from approximately 0 to 105 °C. These properties were comparable to those of commercially available rubbery materials and conventional plastics. The crosslinking densities of the new polymers were largely dependent on the concentration of the crosslinking agent and the type of soybean oil employed and varied from 74 to 4 ? 104 mol/m3. The Tg increased and the intensity of the loss factor decreased irregularly with an increase in the logarithmic crosslinking densities of the polymers. Empirical equations were established to describe the effect of crosslinking on the loss factor in these new polymeric materials. The polymers based on conjugated LoSatSoy oil, styrene, and divinylbenzene possessed the highest room-temperature moduli and Tg 's. These new soybean oil polymers appear promising as replacements for petroleum-based polymeric materials. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2721-2738, 2000

Journal of Applied Polymer Science  Volume 80, Issue 04, 2001. Pages: 658-670
 

New Soybean Oil-Styrene-Divinylbenzene Thermosetting Copolymers. I. Synthesis and Characterization

Fengkui Li, Richard C. Larock *

Department of Chemistry, Iowa State University, Ames, IA 50011

^*Correspondence to Professor R. Larock, Department of Chemistry, Gilman 3709, Iowa State University, Ames, IA 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

Soybean oil, Cationic copolymerization, Gelation, Thermosets.

Abstract

The cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy oil) or conjugated LoSatSoy oil with styrene and divinylbenzene initiated by boron trifluoride diethyl etherate (BF3·OEt2) or related modified initiators provides viable polymers ranging from soft rubbers to hard, tough or brittle plastics.  The gelation time of the reaction varies from 100 to 200000 seconds at room temperature.  The yields of bulk polymers are essentially quantitative.  The amount of crosslinked polymer remaining after Soxhlet extraction ranges from 80 to 92%, depending on the stoichiometry and the type of oil used.  Proton nuclear magnetic resonance spectroscopy and Soxhlet extraction data indicate that the structure of the resulting bulk polymer is a crosslinked polymer network interpenetrated with some linear or less crosslinked triglyceride oil-styrene-divinylbenzene copolymers, a small amount of low molecular weight free oil and minor amounts of initiator fragments.  The bulk polymers possess glass transition temperatures ranging from approximately 0 oC to 105 oC, which are comparable to those of commercially available rubbery materials and conventional plastics.  Thermogravimetric analysis (TGA) indicates that these copolymers are thermally stable under 200 oC, with temperatures at 10% weight loss in air (T10) ranging from 312 to 434 oC, and temperatures at 50% weight loss in air (T50) ranging from 445 to 480 oC.  Of the various polymeric materials, the conjugated LoSatSoy oil polymers have the highest glass transition temperatures Tg and thermal stabilities T10.  These properties suggest that these soybean oil polymers may prove useful where petroleum-based polymeric materials have found widespread utility.© 2000 John Wiley & Sons, Inc. J Appl Polym Sci 80: 658-670, 2001

ELSEVIER

Soybean Oil-Divinylbenzene Thermosetting Polymers: Synthesis, Structure, Properties and their Relationships
 

Fengkui Li, Mark V. Hanson, Richard C. Larock
Department of Chemsitry, Iowa State University, Ames, IA 50011, USA.

The cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy) and conjugated LoSatSoy oil with divinylbenzene initiated by boron trifluoride diethyl etherate (BF₃·OEt₂) or related modified initiators provides polymers ranging from soft rubbers to hard plastics, depending on the reagents, stoichiometry and initiators used.  Nuclear magnetic resonance spectroscopy and dynamic mechanical analysis (DMA) indicate that the resulting polymers are typical thermosets.  The structure of the bulk polymer is that of a densely crosslinked polymer network mixed with a certain amount of less saturated free oil.  The moduli of the bulk polymers are approximately 0.4 - 1.0 GPa at room temperature, which are comparable to those of conventional plastics.  Typically, micro-phase separation occurs in soybean oil and LoSatSoy polymers as evidenced by the appearance of two glass transition temperatures alpha-1 and alpha-2;  alpha-1  (approximately 80 ^oC) is the glass transition temperature of the crosslinked polymer, and alpha-2 (approximately 0 ^oC) corresponds to the solid-liquid transition (glass transition) of the oil-rich phase in the bulk polymer.  In the conjugated LoSatSoy polymers, the crosslinked polymer network becomes more compatible with the unreacted free oil.  Three distinct decomposition temperature regions of the thermosets are observed by thermogravimetric analysis (TGA): 200-400 ^oC, 400-530 ^oC, and above 530 ^oC.  These regions correspond to evaporation and decomposition of the unreacted free oil, degradation and char formation of the crosslinked polymer network, and subsequent oxidation of the char residues in air, respectively.  The thermal stability of these polymers is found to be largely dependent on the amount of unreacted free oil in the bulk polymer.  The conjugated LoSatSoy polymers have the highest moduli and thermal stabilities, since they contain the least unreacted free oil.

Keywords:  Soybean oil, Cationic copolymerization, Thermal analysis, Thermosets
 

Journal of Applied Polymer Science  Volume 78, Issue 5, 2000. Pages: 1044-1056. Copyright © 2000 John Wiley & Sons, Inc.
 

Thermosetting polymers from cationic copolymerization of tung oil: Synthesis and characterization

Fengkui Li, Richard C. Larock *

Department of Chemistry, Iowa State University, Ames, Iowa 50011

^*Correspondence to Richard C. Larock, Department of Chemistry, Iowa State University, Ames, Iowa 50011

Funded by:
Iowa Soybean Promotion Board

Keywords

tung oil; soybean oil; LoSatSoy; cationic copolymerization; thermosets

Abstract

The cationic copolymerization of tung oil with the divinylbenzene comonomer initiated by boron trifluoride diethyl etherate produces promising plastics. The gel times are largely dependent on the relative composition and the reaction conditions and vary from a few seconds to 1 h. Controlled reactions producing homogeneous materials can be obtained by (1) lowering the reaction temperature or (2) decreasing the initiator concentration to less than 1 wt % or (3) adding a certain amount of a less reactive oil, such as soybean oil, low saturation soybean oil (LoSatSoy), or conjugated LoSatSoy to the reaction. The resulting polymers are rigid and dark brown in color. The weight % of the starting materials converted to the crosslinked polymer is 85-98% as determined by Soxhlet extraction with methylene chloride. The structure of the bulk product is that of a crosslinked polymer network plasticized by a small amount of low molecular weight oil. The chemical composition of the bulk polymers varies with the original composition of the tung oil system. Dynamic mechanical analysis shows that the resulting products are typical thermosetting polymers with densely crosslinked structures. The modulus of the plastics is approximately 2.0 ? 109 Pa at room temperature. One broad glass transition is observed at approximately 100°C. Thermogravimetric analysis shows that the tung oil polymers are thermally stable below 200°C with a 10% weight loss in air around 430°C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1044-1056, 2000

ELSEVIER

Fish Oil Thermosetting Polymers: Synthesis, Structure, Properties and their Relationships
 

Fengkui Li ^1,2, David W. Marks ², Richard C. Larock ² and Joshua U. Otaigbe ^1,3*
1Department of Materials Science and Engineering, ² Department of Chemsitry, ³ Department of Chemical Engineering, Iowa State University, Ames, IA 50011, USA.

              The cationic copolymerization of native or conjugated fish oil (FO or CFO) with divinylbenzene (DVB), norbornadiene (NBD) or dicyclopentadiene (DCP) comonomers initiated by boron trifluoride diethyl etherate (BF₃.OEt₂) was conducted in an effort to develop useful biodegradable polymers with rationally designed structures from natural renewable resources.  Polymers ranging from rubbers to hard plastics have been obtained. ¹H NMR, ¹³C NMR, solid-state ¹³C NMR, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA) have been used to characterize the structures and physical properties of the fish oil polymers.  The results indicate that the products are typical thermosetting polymers with densely crosslinked structures.  These polymer materials have densities of approximately 1000 kg/m³, which appear to be independent of their compositions.  The structure of the bulk polymer is composed of 40-85 wt % of crosslinked polymer networks plasticized by 15-60 wt % of unreacted free oil.  The moduli of the FO ( ~ 0.8 GPa ) and CFO ( ~ 1.1 GPa ) polymers at room temperature are found to be comparable to those of conventional petroleum-based plastics.  The glass transition temperatures of the polymers range from 50 to 150 ^oC with a broad transition region.  Thermogravimetric analysis (TGA) indicates three distinct decomposition temperature regions, i.e. 200-400 ^oC, 400-560 ^oC, and 560-800 ^oC, which correspond to evaporation of the unreacted free oil, carbonization of the crosslinked polymer network, and oxidation of the carbon, respectively.  The thermal stability of these materials is found to be largely dependent on the amount of unreacted free oil molecules present in the bulk polymers.  The CFO polymers have higher moduli and thermal stability than the FO polymers due to the lower amount of free oil present in the CFO bulk polymers.

Key words:  Fis