Soybean‐ and castor‐oil‐based thermosetting polymers: Mechanical properties

Maleic anhydride modified soybean‐ and castor‐oil‐based monomers, prepared via the malination of the alcoholysis products of the oils with various polyols, such as pentaerythritol, glycerol, and bisphenol A propoxylate, were copolymerized with styrene to give hard rigid plastics. These triglyceride‐based polymers exhibited a wide range of properties depending on their chemical structure. They exhibited flexural moduli in the 0.8–2.5 GPa range, flexural strength in the 32–112 MPa range, glass transition temperatures (T_g) ranging from 72 to 152°C, and surface hardness values in the 77–90 D range. The polymers prepared from castor oil exhibited significantly improved modulus, strength, and T_g values when compared with soybean‐oil‐based polymers. These novel castor and soybean‐oil‐based polymers show comparable properties to those of the high‐performance unsaturated polyester (UP) resins and show promise as an alternative to replace these petroleum‐based materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1497–1504, 2006     

Styrenated urethane oil synthesis via CuAAC “click” chemistry approach

In this study, a novel route for the modification of sunflower oil-based partial triglycerides with styrene (St) was described. For this purpose, in the first step, copolymers of St and 4-chloromethyl styrene (P(St-co-CMS)) were synthesized by free radical polymerization (FRP) and controlled/living radical polymerization (nitroxide mediated radical polymerization (NMRP)) methods. In the second step, chloro groups of these samples were transformed into azido groups by using NaN₃/DMF and then azido groups were coupled with propargyl alcohol to achieve hydroxyl functional polystyrene chain (PSt-OH) via Cu(I)-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC) “click” chemistry approach. Finally, alcohol groups of PSt-OH and the partial glyceride (PG) were combined by the reaction with toluene 2,4-diisocyanate (TDI). As a result, styrenated urethane oil (PG-TDI-PSt) was obtained as an oil-based binder. The structures were determined by FT-IR, ¹H NMR and GPC analyses, and film properties of the products were examined according to the related standards. (PG-TDI-PSt) gave good film properties, and therefore could be considered as an applicable oil-based binder.     

Synthesis and properties of alkoxysilane-functionalized styrenated oil based polyester

Alkoxysilane-functionalized styrenated oil based polyester hybrid films were prepared by using vinyl trimethoxysilane (VTMS) as an inorganic source. For this purpose, an oil based polyester (PGMA) was first synthesized by the esterification of partial glyceride (PG) mixture with maleic anhydride (MA). Then, PGMA was further reacted with both styrene (St) and the mixture of St and VTMS yielding St–PGMA and St–PGMA–VTMS samples, respectively. The synthesis was carried out by changing VTMS content in the range of 5–15 wt.% in order to investigate the effect of inorganic domains on the film properties. While the films of St–PGMA–VTMS were formed on the appropriate substrates by moisture curing and oxidative polymerization, St–PGMA films were only cured by oxidative polymerization. The characterization of the polymers was done by FTIR, ¹H NMR, DSC, TGA and SEM. FTIR and DSC analyses indicated the completion of the moisture curing process. Film properties such as flexibility, adhesion, water, alkali and acid resistances were determined. All samples showed good film properties. Moreover, in comparison, St–PGMA–VTMS samples exhibited better alkali resistance than St–PGMA due to the contribution of the inorganic domains.     

Styrenation of castor oil and linseed oil by macromer method

In this study a novel macromer technique has been described for the styrenation of triglyceride oils. Macromers were prepared through the interesterification of castor oil with linseed oil followed by esterification with acrylic acid. In this preparation various castor oil/linseed oil ratios were applied to obtain a macromer which gave a copolymer with good film properties after copolymerization with styrene. Macromers were styrenated at 100°C using benzoyl peroxide as an initiator. The styrenation leads to improved film properties with the related interesterification product although castor oil is a non‐drying oil.     

Simultaneous Interpenetrating Polymer Networks of Polyurethane from Pentaerythritol–Modified Castor Oil and Polystyrene: Structure–Property Relationships

Castor oil was transesterified with pentaerythritol thereby introducing reactive hydroxyl groups. The method of matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy was used to determine the components of the castor oil pentaerythritol alcoholysis products. Simultaneous interpenetrating polymer networks of pentaerythritol modified castor oil and diphenyl-methane 4-4′ diisocyanate polyurethane (P1-CO-PU) and polystyrene (PS) were synthesized using benzoyl peroxide as the initiator and divinyl benzene as the crosslinker. The effect of PU/PS composition on the morphology, miscibility and physical properties of the resulting IPNs was investigated by scanning electron microscopy, dynamic mechanical thermal analysis, measurements of mechanical properties and resistance to chemical reagents. The patterns of the extent of the phase separation and the characteristics of the interpenetration reached as a function of the components were deduced.     

Rigid,thermosetting liquid molding resins from renewable resources. I. Synthesis and polymerization of soy oil monoglyceride maleates

In this study, rigid thermoset polymers were prepared from radical copolymerization of the soybean oil monoglyceride maleates with styrene. In the first part of the study, soybean oil monoglycerides (SOMGs) were obtained from the reaction of soybean oil with glycerol at 220–240°C with an optimization of the reaction to maximize the monoglyceride yield. In the following step, SOMG were reacted with maleic anhydride at temperatures around 100°C to produce the SOMG maleate half esters. Different catalysts and different reaction conditions were examined to increase the maleate half esters' yields. The reactions were followed by IR and ¹H NMR, and the products were characterized by mass spectrometry. In the final step, the radical initiated copolymerization of the SOMG maleates with styrene produced rigid, thermoset polymers. The emulsion copolymerization of the SOMG maleates with styrene was also carried out successfully without the addition of an emulsifier. The obtained polymers were characterized by IR and the crosslinked network structure of the copolymers was examined with the swelling behavior in different solvents. Mechanical properties of the cured resin such as T_g, dynamic flexural modulus, and surface hardness were also determined. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 69–77, 2001     

Styrenation of triglyceride oil by nitroxide mediated radical polymerization

Styrenated oil was obtained by nitroxide mediated radical polymerization (NMRP) method in the presence of 2,2′,6,6′-tetramethylpiperidinyl-1-oxy (TEMPO). For this purpose, firstly, macroinitiator having thermally unstable azo groups was obtained with reaction of partial glycerides (PGs) mixture and 4,4′-azobis-4-cyanopentanoyl chloride (ACPC). Then, the macroinitiator was subjected to polymerization with styrene in the presence of TEMPO in order to obtain a copolymer with controlled structure and low polydispersity. The products thus obtained were characterized by GPC, ¹H NMR and FT-IR measurements. A classical styrenated oil was also prepared for comparison. The film properties of the products were determined according to the related standards and compared with each other. The product obtained at the end of the 72 h in the presence of TEMPO showed to some extent brittle film properties. To improve the film properties, this product was further reacted with the oil-based vinyl macromonomer (MM). The styrenated oil samples prepared by the controlled polymerization method, exhibited relatively low polydispersity (<1.5) and showed good film properties.     

Fatty acid‐based comonomers as styrene replacements in soybean and castor oil‐based thermosetting polymers

In this study, a fatty acid‐based comonomer is employed as a styrene replacement for the production of triglyceride‐based thermosetting resins. Styrene is a hazardous pollutant and a volatile organic compound. Given their low volatility, fatty acid monomers, such as methacrylated lauric acid (MLA), are attractive alternatives in reducing or eliminating styrene usage. Different triglyceride‐derived cross‐linkers resins were produced for this purpose: acrylated epoxidized soybean oil (AESO), maleinated AESO (MAESO), maleinated soybean oil monoglyceride (SOMG/MA) and maleinated castor oil monoglyceride (COMG/MA). The mechanical properties of the bio‐based polymers and the viscosities of bio‐based resins were analyzed. The viscosities of the resins using MLA were higher than that of resins with styrene. Decreasing the content of MLA increased the glass transition temperature (T_g). In fact, the T_g of bio‐based resin/MLA polymers were on the order of 60°C, which was significantly lower than the bio‐based resin/styrene polymers. Ternary blends of SOMG/MA and COMG/MA with MLA and styrene improved the mechanical properties and reduced the resin viscosity to acceptable values. Lastly, butyrated kraft lignin was incorporated into the bio‐based resins, ultimately leading to improved mechanical properties of this thermoset but with unacceptable increases in viscosity. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Polyesters from renewable resources: Preparation and characterization

Polyesters were synthesized with monoglycerides prepared from rubber seed oil, a renewable resource. Monoglycerides were obtained by an alcoholysis method from the oil, which was neat or modified by treatments with different amounts of maleic anhydride at 230°C. The polyester resins were subsequently prepared by the condensation polymerization of the monoglycerides with phthalic anhydride. The monoglycerides and resins were characterized by spectroscopic analysis and measurements of the physicochemical properties. The chemical resistance of the polyesters was also studied. The results revealed that the polyesters prepared from the modified monoglycerides possessed better properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3748–3755, 2006     

Styrenated sunflower oil polymers from raft process for coating application

Oil-based macroinitiator (MI) obtained from sunflower oil was styrenated using reversible addition–fragmentation chain transfer polymerization (RAFT) in the presence of phenacyl morpholine dithiocarbamate (PMDC) as chain transfer agent. The solvent effect and effect of the molar ratio of the transfer agent, PMDC, on polydispersity and molecular weight of the polymers were investigated. The obtained results showed that, 1,4-dioxane is a better solvent and 1/4 molar ratio of [MI]/[PMDC] provides relatively low polydispersities. No homopolystyrene was detected under these conditions, indicating the efficiency of PMDC in the chain transfer process. Livingness of the polymerization process was confirmed by chain extension with styrene using the preformed polymer as macrotransfer agent. The film properties of styrenated oil samples were determined according to the related standards. To improve film properties, the polymer obtained by RAFT technique was modified by reaction with MI. The resulting material gave transparent films with good film properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Thermal and mechanical properties of acrylated expoxidized‐soybean oil‐based thermosets

A series of epoxidized‐soybean oil (ESO) with different epoxyl content were synthesized by in situ epoxidation of soybean oil (SBO). The acrylated epoxidized‐soybean oil (AESO) was obtained by the reaction of ring opening of ESO using acrylic acid as ring opener. The acrylated expoxidized‐soybean oil‐based thermosets have been synthesized by bulk radical polymerization of these AESOs and styrene. The thermal properties of the resins were characterized by differential scanning calorimetry (DSC) and thermo‐gravimetric analysis (TG). The results showed that these resins possess high thermal stability. There were two glass transition temperature of each resin due to the triglycerides structure of the resins. The tensile strength and impact strength of the resins were also recorded, and the tensile strength and impact strength increased as the iodine value of ESO decreased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polyurethane Dispersions Based on Interesterification Product of Fish and Linseed Oil

Alkyd and styrenated alkyd resins based on fish oil and their interesterifications with linseed oil were synthesized. The various properties of fish oil, such as its iodine value, acid value, saponification value and moisture content were determined. The interesterification product of fish oil and linseed oil can be used to partially replace the commercially available linseed oil alkyd resin. Alkyd resin and styrenated alkyd resin were modified with 2,2 dimethylolpropionic acid to introduce acid functionality and then sequentially reacted with isophorone diisocyanate, neutralized with amine, chain extended with ethylenediamine and dispersed in water to form a polyurethane dispersion. The newly synthesized resins and polyurethane dispersions were studied for coating properties such as scratch hardness, adhesion, flexibility, impact, solvent and chemical resistance. The polyurethane dispersions exhibited superior coating properties to those of their respective alkyds and styrenated alkyds.     

Reactions of unsaturated fatty alcohols. XIV. Preparation and properties of styrenated fatty vinyl ether polymers

New polymeric products have been prepared from conjugated linseed vinyl ether polymers and styrene. Up to 64% by weight of styrene can be incorporated by heating the preformed fatty vinyl ether polymer and monomeric styrene in an aromatic solvent. Primary factors influencing the course of the reaction were molecular weight and peroxide content of the starting vinyl ether polymer, reaction temperature, and type of solvent used. Formation of heterogeneous reaction products and gelation were encountered unless styrene was consumed in the reaction or removed. Films of these styrenated vinyl ether polymers show improved properties over the homopolymers previously studied. Baked films exhibit better gloss, color, and hardness; are more throughly cured; and show good flexibility and adhesion. Their resistance to 5% aqueous alkali is outstanding. The films also exhibit air-drying properties. Fatty vinyl ether polymers and copolymers have shown only limited compatibility with commericial resins. However, styrenated polymers are compatible with long oil alkyd, urea, epoxy, hydrogenated rosin, and polyurethane resins. Presented at AOCS meeting, St. Louis, Mo., May 1–3, 1961. A laboratory of the Northern Utilization Research and Development Division Agricultural Research Service, U.S.D.A.     

Rigid thermosetting liquid molding resins from renewable resources. II. Copolymers of soybean oil monoglyceride maleates with neopentyl glycol and bisphenol A maleates

Soybean oil monoglycerides (SOMG), obtained by the glycerolysis of soybean oil, were reacted with maleic anhydride to produce SOMG maleate half esters. The copolymers of the SOMG maleates with styrene produced rigid thermosetting polymers. The dynamic mechanical analysis (DMA) of this polymer showed a glass‐transition temperature (T_g) around 133°C and a storage modulus (E′) value around 0.94 GPa at 35°C. The tensile tests performed on this polymer showed a tensile strength of 29.36 MPa and a tensile modulus of 0.84 GPa. Mixtures of SOMG with neopentyl glycol (NPG) and SOMG with bisphenol A (BPA) were also maleinized under the same reaction conditions and the resulting maleates were then copolymerized with styrene. The resulting polymers were analyzed for their mechanical properties. The T_g of the copolymers of the SOMG/NPG maleates with styrene was 145°C and the E′ value at 35°C was 2 GPa. The tensile strength of this polymer as calculated from the stress–strain data was 15.65 MPa and the tensile modulus was 1.49 GPa. The T_g of the copolymers of SOMG/BPA maleates, on the other hand, was found to be around 131°C and the E′ value was 1.34 GPa at 35°C. The changes observed in the mechanical properties of the resulting polymers with the introduction of NPG maleates and BPA maleates to the SOMG maleates can be explained by the structural changes on the polymer backbone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 972–980, 2002     

Polymerization reactions of epoxidized soybean oil and maleate esters of oil‐soluble resoles

In this study, the polymerization reactions of epoxidized soybean oil (ESO) with the maleate half‐esters of oil‐soluble resoles and the properties of the final products were demonstrated. The maleate half‐esters of the dimeric oil‐soluble resoles were obtained by the esterification reaction of maleic anhydride with a p‐tertiary butyl phenol (p‐TBP) resole and p‐nonyl phenol resole resins in the first step. The monomers were characterized by IR and ¹H‐NMR techniques. Then, the oil‐soluble resole maleates were polymerized with ESO to obtain tough and load‐bearing thermoset materials. The thermal and mechanical properties of the materials were determined by dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, and tensile strength testing. The tensile strengths and storage moduli of the crosslinked polymers varied between 0.17 and 13 MPa and 10 and 1088 MPa, respectively. The elongation percentages of the materials were between 1 and 128%. The thermal resistance of the thermosets was measured as the 5% weight loss temperature. The reaction product of the ESO and maleate ester of p‐TBP showed the highest 5% weight loss at 247°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41457.     

Synthesis and characterization of alkyd resins based on Camelina sativa oil and polyglycerol

A one pot synthesis of alkyd resins based on the Camelina sativa oil as a new renewable raw material and on polyglycerols as polyols was carried out. The oligomerization of glycerol was conducted in the presence of LiOH (0.1 wt%) at 245 °C. The total content of diglycerol reached its maximum (about 33.5 wt%) after 7 h. The oligomerization product with no additional treatment was subjected to the alcoholysis reaction with purified camelina oil. The alkyd resin was obtained after polycondensation of the alcoholysis products with phthalic and maleic anhydrides at 230–250 °C. A real possibility was determined for the synthesis of alkyd resins with some properties similar to those which can be found in equivalent products manufactured on the basis of semi drying oil and pentaerythritol like flexibility and drying time.     

Monomer-grafted sucrose ester resins

Styrenated sucrose esters of soybean fatty acids were successfully synthesized and the coatings properties were found to be comparable to a commercial styrenated alkyd while having lower volatile organic content at comparable solids content. A series of reactions were performed which varied the percent styrene incorporated into the resin. The dry time was significantly reduced as the styrene content increased which was a result of having more hard polystyrene chain segments. Tack-free times of ≈30 min were observed for resins containing high amounts of polystyrene. Nuclear magnetic resonance spectroscopy indicated residual bisallylic hydrogens were present which are capable of further crosslinking through autoxidation after film application. The addition of cobalt and zinc driers reduced the drying time which indicates that autoxidation is occurring. Furthermore, the styrenation reaction was extended to make water-reducible resins. These resins were crosslinked with a melamine–formaldehyde resin resulting in biobased thermosets having high solvent resistance, high hardness while retaining good flexibility.     

Ecofriendly Autoxidation of Castor Oil/Ricinoleic Acid. Multifunctional Macroperoxide Initiators for Multi Block/Graft Copolymers

Ecofriendly autoxidation is a reaction of air oxygen with unsaturated organic molecules at room temperature. Castor oil and ricinoleic acid were ecofriendly autoxidized for 5 months to obtain castor oil macroperoxide with a Mn of 1935 g mol⁻¹ (Pcast5m) and the ricinoleic acid macroperoxide initiator (Prici5m) with a Mn of 1169 g mol⁻¹. Peroxide groups thermally initiated the free radical polymerization of methyl methacrylate (MMA), n-butyl methacrylate (nBMA), and styrene (S). Peroxide formation in the oxidized castor oil and ricinoleic acid was confirmed using iodometric analysis, elemental analysis, and differential scanning calorimetry technique. Peroxide decomposition in both macroperoxide initiators was observed at 166 °C for Prici5m and 170 °C for Pcast5m. Hydroxyl groups of Pcast5m were reacted with methacryloyl chloride to obtain methacrylated castor oil macroperoxide (PcastMA). The polymerization rates of the obtained macroinitiators were compared. The polymerization rate order is Pcast5m > Prici5m > PcastMA. Polymerization of styrene by PcastMA resulted in an increase in molar masses and an increase in the polymerization time while those of the styrene polymerization by Pcast5m and Prici5m remained constant. Carboxylic acid groups were reacted with amine-terminated polyethylene glycol (PEG), polydimethyl siloxane (PDMS), and polytetrahydrofuran (PTHF) while the hydroxyl functionality initiated the ring-opening polymerization of ε-caprolactone (CL). Prici-PEG-PMMA, Prici-PS-PDMS, Prici-PS-PTHF, Pcast-PS-PCL, Pcast-PCL-PMMA, and Pcast-PS-PnBMA multiblock copolymers were prepared and characterized using spectrometric, thermal, and stress–strain measurement techniques.     

蓖麻油基聚酯多元醇的制备及表征

以可再生资源蓖麻油、苯酐和小分子醇为原料,钛酸正丁酯为催化剂,经酯化、缩聚合成蓖麻油基聚酯多元醇,考察了反应时间对聚酯多元醇酸值的影响以及不同官能度的小分子醇对醇解蓖麻油结构和羟值的影响。采用红外光谱仪（FT—IR）、凝胶色谱（GPC）、热失重仪（TGA）对醇解蓖麻油、蓖麻油基聚酯多元醇的相对分子质量、热稳定性进行了表征。结果表明,随着小分子醇官能度的增加,醇解体系中单酯和二酯含量明显减少,转化率也相应减小;甘油醇解蓖麻油和蓖麻油基聚酯多元醇较普通聚醚多元醇635具有更高的热稳定性。     

The effect of alkyd resins on the properties of AA‐NC semi‐IPNs as binders in wood finish

Wood coatings of AA‐NC semi‐interpenetrating polymer networks (semi‐IPNs), made from acid curing amino‐alkyd resins (AA) and nitrocellulose (NC), were prepared by sequential polymerization method. To investigate the effects of oil length on the properties of AA‐NC semi‐IPNs, three grades of alkyd resins (Alkyd) containing 38, 48, and 58% oil were synthesized with phthalic anhydride, glycerol, and soybean oil, employing alcoholysis method. The butylated urea formaldehyde resin (UF) and melamine formaldehyde resin (MF) were also prepared in this study. The AA‐NC semi‐IPNs were maintained at a weight ratio of AA : NC of 25 : 75, where the AA was the composition of MF : UF : Alkyd of 7.5 : 22.5 : 70 (by weight), and 10% of p‐toluene sulfonic acid solution (concentration, 25% in isopropyl alcohol) based on the weight of amino resins was added as acid catalyst. The properties of coatings such as viscosity, drying time, and gel time, and the properties of films including adhesion, hardness, abrasion resistance, impact resistance, tensile strength, released formaldehyde, lightfastness, solvent resistance, and durability were examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1923–1927, 2004