Optimization of Soybean Oil Based Pressure-Sensitive Adhesives Using a Full Factorial Design

Plant oils are attractive renewable feedstocks for biobased pressure‐sensitive adhesives (PSAs). In this study, we investigated how the PSA adhesion properties were influenced by the compositions comprised of epoxidized soybean oil (ESO), 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexanecarboxylate (ECHM), dihydroxyl soybean oil (DSO), rosin ester, and cationic photo initiator. When the amounts of ESO and photo‐initiator were constant, the variables of ECHM, DSO, and rosin amounts and their interactions were significant in influencing PSA peel adhesion strength, with p values smaller than 0.05 under a 95% significance level. Rosin amounts with the largest coefficient of 0.94 compared to the other variables are the most determinant factors. The peel adhesion strength was higher when using relatively a lower level of ECHM and a higher level of ESO and rosin. A model with the coefficient of determination (R²) of 95.06% was obtained to describe the relationship between the amount of resin constituents (ECHM, DSO, and rosin) and PSA peel adhesion strength in the experimental variable ranges. The optimal PSA formulation without cohesive failure was (ECHM = 0.04, DSO = 0.7, rosin = 0.7), resulting in a peel adhesion strength of 4.45 N/in. Structure–property relationships of the PSAs were established via thermal and rheological studies.     

环氧大豆油增韧酚醛树脂/蒙脱土复合材料力学性能研究

采用环氧大豆油和有机蒙脱土复合改性酚醛树脂以提高材料的力学性能。环氧大豆油可通过醚键接枝在酚醛树脂上,向树脂中引入柔性长链来提高树脂韧性;蒙脱土可通过聚合插层,在树脂中形成“网—点”结构,从而大幅提高材料的力学性能。研究结果表明,环氧大豆油的加入量为40 ％（质量分数,下同）时,能使酚醛树脂的冲击强度提高72 ％,弯曲强度可达到94 MPa,断裂伸长率为4.5 ％。在此基础上,有机蒙脱土的加入量为2 ％时,材料的冲击强度可提高42.2 ％,弯曲强度为111 MPa,断裂伸长率为5.6 ％,拉伸强度为30.8 MPa。综合比较,加入40 ％的环氧大豆油,2 ％的有机蒙脱土对材料力学性能改善效果最佳。     

UV‐curable pressure‐sensitive adhesives derived from functionalized soybean oils and rosin ester

Functionalized plant oils such as epoxidized soybean oil (ESO) are widely used in plastic industries as additives and are available for more value‐added applications. Pressure‐sensitive adhesive (PSA) derived from petroleum feedstocks has a huge market ranging from tapes to packaging. Here we show a sustainable PSA derived from ESO/dihydroxyl soybean oil (DSO)/rosin ester (Sylvalite) via UV‐initiated copolymerization. The ether crosslinks derived from cationic polymerization of ESO and copolymerization between ESO and DSO (or rosin ester) were demonstrated using ¹H NMR, 2D ¹H–¹H COSY NMR, electrospray ionization mass spectrometry and thermal analyses (differential scanning calorimetry and thermogravimetric analysis). The PSA was formulated by modulating the ratio of ESO/DSO/rosin ester to achieve high performance. At a UV dose of 5.1–5.4 J cm^?2 and 0.3–3% (w/w) of a photoinitiator, i.e. [4‐(2‐hydroxy‐1‐tetradecyloxy)‐phenyl]phenyliodonium hexafluoroantimonate, the PSA at a ratio (by weight) of 1:1:0.7 (ESO/DSO/rosin ester) recorded the highest peel and loop tack strength, which was comparable to a commercial PSA, Scotch Magic Tape, and showed much stronger shear strength (>30 000 min) than the commercial tape (10 000 min). The high‐shear rheological behavior and excellent thermal stability of the PSA were also demonstrated. © 2012 Society of Chemical Industry     

Oxirane Cleavage Kinetics of Epoxidized Soybean Oil by Water and UV‐Polymerized Resin Adhesion Properties

Di‐hydroxylated soybean oil (DSO), a biobased polyol synthesized from epoxidized soybean oil (ESO) could be used to formulate resins for adhesives; however, current DSO synthesis requires harsh reaction conditions that significantly increase both cost and waste generation. In this paper, we investigate the kinetics of oxirane cleavage in ESO to DSO by water and elucidate the role of different process parameters in the reaction rate and optimization of reaction conditions. Our kinetic study showed that ESO oxirane cleavage was a first‐order reaction and that the ESO oxirane cleavage rate was greatly influenced by tetrahydrofuran (THF)/ESO ratio, H₂O/ESO ratio, catalyst content, and temperature. Optimized reaction parameters were THF/ESO of 0.5, H₂O/ESO of 0.25, catalyst content of 1.5 %, and reaction time of 3 h at 25 °C. DSO with hydroxyl value of 242 mg KOH/g was obtained under these conditions. We also characterized the structure, thermal properties, adhesion performance, and viscoelasticity of UV‐polymerized resins based on this DSO. The resin tape exhibited peel adhesion strength of 3.6 N/in., which is comparable to some commercial tapes measured under similar conditions.     

Mechanical and rheological properties of epoxidized soybean oil plasticized poly(lactic acid)

Poly(lactic acid) (PLA) is a well known biodegradable thermoplastic with excellent mechanical properties that is a product from renewable resources. However, the brittleness of PLA limits its general applications. Using epoxidized soybean oil (ESO) as a novel plasticizer of poly(lactic acid), the composite blend with the twin‐screw plastic extruder at five concentrations, 3, 6, 9, 12, and 15 wt %, respectively. Compared with pure PLA, all sets of blends show certain improvement of toughness to different extents. The concentration with 9 wt % ESO increases the elongation at break about 63%. The melt flow rates of these blends with respect to different ESO ratio have been examined using a melt flow indexer. Rheological behaviors about shear viscosity and melt strength analysis are discussed based on capillary rheology measurements. The tensile strength and melt strength of the blends with 6 wt % ESO simultaneity reach the maximums; whereas the elongation at break of the blends is the second highest level. ESO exhibits positive effect on both the elongation at break and melt strength. The results indicate that the blend obtained better rheological performance and melt strength. The content of 6 wt % ESO in PLA has been considered as a better balance of performance. The results have also demonstrated that there is a certain correlation between the performance in mechanical properties and melt rheological characterization for the PLA/ESO blends.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of a biodegradable mulch: Paper coated with polymerized vegetable oils

Kraft paper was coated with resins based on vegetable oils and then tested for mechanical properties, rate of biodegradation in soil, and ability to inhibit weed growth. Resins included oxidatively polymerized linseed oil (LO) and a polyester formed by the reaction of epoxidized soybean oil and citric acid (ESO–CA). Tensile strength of LO-coated paper (82 MPa) was slightly higher than uncoated paper (68 MPa), while the tensile strength of ESO–CA coated paper was somewhat lower (45 MPa). Elongations to break (3–8%) were similar for all samples. The rates of weight loss and tensile strength during soil burial decreased as follows: uncoated paper > LO coated paper > ESO–CA coated paper. The polymerized oils acted as barriers to penetration of microorganisms to the cellulosic fibers. Resin-coated papers inhibited weed growth for > 10 weeks, while uncoated paper was highly degraded and ineffective by 6–9 weeks. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2159–2167, 1999     

Phosphate Esters Functionalized Dihydroxyl Soybean Oil Tackifier of Pressure-Sensitive Adhesives

Dihydroxyl soybean oil (DSO) has shown potential as a tackifier for pressure-sensitive adhesive (PSA) applications, and perchloric acid was used previously as a catalyst to open the oxirane rings of epoxidized soybean oils (ESO) when we prepared DSO and PSA. Phosphoric acid is a more eco-friendly catalyst than perchloric acid; therefore, the objective of this work was to prepare DSO using phosphoric acid as a catalyst and thereby create DSO-contained phosphate esters, or PDSO. The chemical scaffolds of PDSO were elucidated with ¹H, ¹H–¹H COSY, ³¹P NMR, FTIR, MALDI-TOF MS, and GPC. ESO PSAs were prepared from a mixture of ESO/PDSO. The ESO PSA prepared with PDSO had peel strength on a plastic carrier comparable to commercial PSA, and while on an aluminum carrier, the ESO PSA had a stronger peel strength. ESO PSA prepared with phosphoric acid was also stronger than the peel strength of the ESO PSA prepared with DSO using perchloric acid.     

Effect of functionality and content of epoxidized soybean oil on the physical properties of a modified diglycidyl ether of bisphenol A resin system

Partially epoxidized soybean oil (pESO) and fully epoxidized soybean oil (fESO) were used respectively to modify a diglycidyl ether of bisphenol A (DGEBA) resin system in this study. The pESO was prepared by epoxidizing soybean oil and the fESO was purchased as it was commercially available. DGEBA/ESO ratio of the epoxy resin system was changed from 100/0 to 70/30 and triethylenetetramine was used as a curing agent. Impact strength of the bio-epoxy resin system with fESO increased with ESO content, but the system with pESO decreased with ESO content. The bio-epoxy resin system with pESO showed higher tensile strength and elongation at break than the system with fESO at ESO 30 wt%. Tensile modulus and thermal degradation temperature decreased with ESO content and glass transition temperature was highest at 20 wt% ESO regardless of epoxide functionality of ESO. The performance of the DGEBA/ESO bio-epoxy resin system could be tailored by changing ESO content and functionality.     

Biocomposites composed of epoxidized soybean oil cured with terpene‐based acid anhydride and cellulose fibers

Epoxidized soybean oil (ESO) was cured with a terpene‐based acid anhydride (TPAn) at 150°C, and the thermal and mechanical properties of the cured product were compared with ESO cured with hexahydrophthalic anhydride (HPAn), maleinated linseed oil (LOAn), or thermally latent cationic polymerization catalyst (CPI). The ESO‐TPAn showed a higher glass transition temperature (67.2°C) measured by dynamic mechanical analysis than ESO‐HPAn (59.0°C), ESO‐LOAn (?41.0°C), and ESO‐CPI (10.0°C). The storage modulus at 20°C of ESO‐TPAn was higher than those of ESO‐LOAn and ESO‐CPI. Also, ESO‐TPAn showed higher tensile strength and modulus than the other cured ESOs. Regarding the biodegradability measured by biochemical oxygen demand in an activated sludge, ESO‐TPAn possessed some biodegradability, which was lower than that of ESO‐LOAn. Next, biocomposites composed of ESO‐TPAn and regenerated cellulose (lyocell) fabric were prepared by compression molding method. The tensile strength of ESO‐TPAn/lyocell composites increased with increasing fiber content. The tensile strength and modulus of ESO‐TPAn/lyocell composite with fiber content 75 wt % were 65 MPa and 2.3 GPa, which were three times higher than those of ESO‐TPAn. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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.     

光敏预聚物丙三醇三缩水甘油醚三丙烯酸酯的合成

以N,N 二甲基苄胺为催化剂、对羟基苯甲醚为阻聚剂,用丙三醇三缩水甘油醚和丙烯酸为主要原料合成了一种新型光敏预聚物———丙三醇三缩水甘油醚三丙烯酸酯。研究了反应温度,阻聚剂、催化剂用量等因素对反应的影响,优化的合成反应条件是温度90～110℃、N,N 二甲基苄胺的质量分数为0 80%～1 00%、对羟基苯甲醚的质量分数为0 20%～0 40%。把所合成的光敏预聚物加入光引发剂配成了光固化涂料,对其紫外光固化涂料膜进行了拉伸实验,测得其拉伸强度为27 14MPa,弹性模量946 85MPa,断裂伸长率3 72%。     

Interpenetrating polymer network structured thermosets prepared from epoxidized soybean oil/diglycidyl ether of bisphenol A

Epoxidized soybean oil (ESO)/diglycidyl ether of bisphenol A (DGEBA) in various blend ratios (i.e. 100/0, 90/10, 80/20, 70/30, 60/40, 50/50) was thermally cured using methylhexahydrophthalic anhydride in the presence of 2‐ethyl‐4‐methylimidazole catalyst. The tensile properties and fracture toughness of the ESO/DGEBA thermoset blends were determined. Thermal properties of the blends were characterized using dynamic mechanical analysis, differential scanning calorimetry and thermogravimetric analysis. Blending of ESO and DGEBA gave synergistic effects on the modulus, strength, glass transition temperature and thermal stability. However, the fracture toughness and elongation at break of ESO/DGEBA blends are lower than those of ESO, as expected. The enhancement in certain mechanical and thermal properties of ESO/DGEBA can be associated with the crosslink density, gel content and possible interpenetrating network of the resulting thermoset blends. © 2013 Society of Chemical Industry     

KH-570对硅丙核/壳乳液合成及性能影响的研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和丙烯腈(AN)为主要原料,γ-(甲基丙烯酰氧基)丙基三甲氧基硅烷(KH-570)为改性剂,采用半连续种子乳液二阶段聚合法制备出一种核/壳结构型硅丙乳液。研究结果表明:KH-570含量对胶膜吸水率影响较小;胶膜力学性能及其保持率随KH-570含量增加而增大;当w(KH-570)=5%(相对于单体总质量而言)时,乳液及其胶膜的综合性能相对最好,其吸水率、拉伸强度和断裂伸长率分别为6.92%、13.37 MPa和43.98%,吸水48 h后拉伸强度和断裂伸长率分别为12.01 MPa和40.02%,吸水48 h后拉伸强度和断裂伸长率的保持率分别为89.83%和91.41%。     

Di-Hydroxylated Soybean Oil Polyols with Varied Hydroxyl Values and Their Influence on UV-Curable Pressure-Sensitive Adhesives

Di-hydroxylated soybean oil (DSO) polyols with three different hydroxyl values (OHV) of 160, 240, and 285 mg KOH/g were synthesized from epoxidized soybean oils (ESO) by oxirane cleavage with water catalyzed by perchloric acid. The DSO were clear, viscous liquids at room temperature. The structure and physical properties of DSO were characterized using titration methods, Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography, rheometer, differential scanning calorimetry, and thermogravimetric analysis. The number average molecular weight of DSO160, DSO240, and DSO285 were 1,412, 1,781, and 1,899 g/mol, respectively, indicating that oligomerization occurred during DSO synthesis, which was further confirmed by FTIR. All DSO polyols exhibited non-Newtonian, shear thinning behavior. DSO with higher OHV were more viscous than those with lower OHV. All DSO were thermally stable up to 380 °C. These three DSO were formulated into pressure-sensitive adhesives (PSA) by copolymerizing with ESO using UV curing. The peel adhesion strength of the PSA was significantly affected by the OHV of DSO and DSO content. Maximal PSA adhesion strength of 4.6 N/inch was obtained with DSO285 and a DSO/ESO weight ratio of 0.75.     

大豆分离蛋白/淀粉可生物降解材料的性能研究

大豆分离蛋白(SPI)和淀粉混合物经丁二酸酐改性,经甘油和水增塑之后,热压得到力学性能较好的可生物降解材料。以材料的断裂伸长率和拉伸强度作为力学性能的考察指标,并利用FTIR对其进行了分析,结果表明:添加淀粉后,材料的力学性能有了很大提高,SPI与淀粉发生了Maillard反应,断裂伸长率为353%,拉伸强度为7.30MPa。     

Crosslinked glutinous rice starch filled polyvinyl alcohol films

The influence of glutinous rice starch (GRS) content and sodium hexametaphosphate (SHMP) in polyvinyl alcohol (PVOH) films were studied. The increase of GRS content (0–40 wt%) reduced the tensile strength (from 14.3 to 4.3 MPa) and elongation at break (from 183 to 52.5) of PVOH/GRS films. Nevertheless, the modulus of elasticity of PVOH/GRS films increased with GRS content, from 20.3 to 132.83 MPa. SHMP was used as a crosslinking agent, which improved more than 30% of tensile strength and modulus of elasticity of PVOH/GRS films. However, the elongation at break reduced after crosslinking process of the films. The crosslinked film showed better interaction between GRS and PVOH, as demonstrated by scanning electron microscopy. Conversely, the crosslinked films exhibited a lower swelling degree, but a higher gel content compared to uncrosslinked films. J. VINYL ADDIT. TECHNOL., 25:359–365, 2019. © 2019 Society of Plastics Engineers     

基于异构联苯二酐的热塑性聚酰亚胺性能研究

制备了一系列基于异构联苯二酐[2,2’,3,3’-联苯四甲酸二酐(3,3’-BPDA)、2,3’,3,4’-联苯四甲酸二酐(3,4’-BPDA)和3,3’,4,4’-联苯四甲酸二酐(4,4’-BPDA)]的聚酰亚胺(PI)均聚物和共聚物,比较研究了这些聚合物的热学和力学性能。结果表明,当二胺结构相同时,基于3,3’-BPDA和3,4’-BPDA的PI均聚物或共聚物较基于4,4’-BPDA的均聚物有更高的玻璃化转变温度(Tg)和更好的热加工性;当二酐结构相同时,基于对苯二胺(PDA)的PI的Tg高于基于4,4’-二氨基二苯醚(ODA)的PI。基于3,4’-BPDA/PDA的PI具有最高的Tg,其值为382℃,由其制备的薄膜的拉伸强度为100 MPa,拉伸弹性模量为1.8 GPa,断裂伸长率为12%。基于4,4’-BPDA/PDA的PI薄膜具有最高的拉伸性能,其拉伸强度为307 MPa,拉伸弹性模量为4.1 GPa,断裂伸长率为23%。基于3,4’-BPDA/ODA和3,3’-BPDA/4,4’-BPDA(1/1)/ODA的PI模塑料均具有高于300℃的Tg和较好的力学性能,其冲击强度分别达到82.3 kJ/m2和94 kJ/m2。     

木质素聚氨酯薄膜合成条件及性能的研究

以麦草碱木质素、相对分子质量为300和 1000 的聚乙二醇(PEG)及多苯基甲烷多异氰酸酯(PAPI)为原料,以N,N-二甲基甲酰胺为溶剂,使用溶液浇注法固化成型工艺,制备了碱木质素聚氨酯薄膜。通过调整PEG1000与PEG300的比例提高了聚氨酯的力学性能。测定了木质素聚氨酯薄膜的弹性模量、拉伸强度和断裂拉伸率、耐撕裂度。实验结果表明,调节不同相对分子质量聚乙二醇在反应体系中的比例,可以显著提高成膜后的耐撕裂性能,改善由于加入木质素后聚氨酯薄膜过脆的缺点。当使用PEG1000与PEG300物质的量之比值为2.0,异氰酸酯指数为2.5,木质素加入量为 20%(质量分数)时,聚氨酯薄膜的弹性模量为 1.49 GPa、拉伸强度为 36.5 MPa、断裂拉伸率为 12.7%,耐撕裂度为 8460 mN,且成膜性能良好。     

Spider Silk Inspired Robust and Photoluminescent Soybean-Protein-Based Materials

Development of mechanical robust and functional biomass-based materials still remains challenging. Here, a design strategy inspired by spider silk structure is proposed to prepare strong, robust, and photoluminescent soybean protein isolate (SPI)-based materials, by integrating epoxy soybean oil (ESO) and SPI as soft phase matrices and graphene oxide quantum dots (GQDs) as hard phase. The results show that the soft–hard coordination network can form a close covalent/hydrogen bond network. The tensile strength, elongation at break, and toughness of the SPI/ESO/GQD film are 13.22 MPa, 209%, and 22.54 MJ m⁻³, respectively. In addition, SPI/ESO/GQD has strong photoluminescence intensity due to the ring-opening polymerization of amino structure with epoxy resin. The prepared SPI-based materials are promising candidates for optical coatings and provide new ideas for the intelligent research of other protein-based materials.     

聚己内酯/聚乳酸/竹纤维复合材料制备及性能

以聚己内酯（PCL）和聚乳酸（PLA）共混物为基材,竹纤维（BF）作为增强材料,硅烷偶联剂为改性剂,通过模压成型制备了PCL/PLA/BF复合材料。研究了PCL和PLA质量比、BF质量分数、硅烷偶联剂用量以及模压温度对复合材料性能影响。结果表明,适宜的PCL/PLA质量比为1∶1,BF质量分数为40 %时BF/PCL/PLA复合材料的冲击强度、拉伸强度和断裂伸长率分别达到最大值11.26 kJ/m2,12.68 MPa和5.2 %;硅烷偶联剂用量为1 %时复合材料的冲击强度、拉伸强度和断裂伸长率分别达到最大值15.11 kJ/m2、13.15 MPa和5.8 %;模压温度为150 ℃时,复合材料的冲击强度、拉伸强度和断裂伸长率分别达到最大值14.51 kJ/m2、13.75 MPa和5.8 %。