Bio-based compatibiliser enhancing the interface properties of CaCO3/recycled high-density polyethylene composites

The fabrication of composites of two or more materials with different polarities requires the use of compatibilisers to improve interface properties. However, most compatibilisers used for industrial production are derived from the cracking products of petroleum, which is a limited resource susceptible to price fluctuations and pollutes the environment. In this study, a new compatibiliser derived from renewable plant-oil-based products, ESO–G–OA, was designed and synthesized using epoxy soybean oil, oleic acid, and glycerol. Scanning electron microscopy results showed that ESO–G–OA can effectively improve the dispersion of CaCO₃ in a recycled high-density polyethylene (reHDPE) matrix and reduce the interfacial gap between the two phases. The analysis of the mechanical properties showed that the ESO–G–OA-modified composite has higher tensile and impact strength than unmodified samples. The ESO–G–OA modification improved the thermal stability and melt flow of the composite and reduced the energy consumption during processing. Moreover, the excellent compatibility of ESO–G–OA can improve the comprehensive properties of CaCO₃/reHDPE composites, compensating for the performance reduction caused by the multiple processing steps necessary to obtain reHDPE. This confirmed that ESO–G–OA has promising application prospects in the production of composites requiring compatibilisers.     

环氧大豆油低聚物增韧环氧树脂胶粘剂

合成了三种环氧大豆油低聚物作为室温和高温固化环氧树脂增韧剂,对其增韧环氧体系的粘接性能和力学性能进行了考察。试验结果表明,环氧树脂低聚物对固化体系的初期粘度等性能没有影响,对固化体系粘接性能和力学性能等有较大影响。与未改性的环氧树脂相比,由顺丁烯二酸酐扩链的环氧大豆油低聚物改性的环氧树脂剪切强度提高了56.64%。     

茶粉/聚乳酸复合材料的增韧改性

为高值化利用茶产业剩余物资源,以茶粉（TD）为生物质填料,聚乳酸（PLA）为基体,以甘油（GL）、聚乙二醇400（PEG400）、环氧大豆油（ESO）和乙酰柠檬酸丁酯（ATBC）为增塑剂,制备了可降解TD/PLA增韧复合材料,并采用红外吸收光谱、热重分析、转矩流变仪、扫描电镜及力学性能测试等考察了增塑剂对TD/PLA复合材料结构与性能的影响。结果表明：4种增塑剂都可改善TD/PLA复合材料的加工流变性,GL的添加不利于复合材料韧性,PEG、ATBC及ESO的添加提高了复合材料韧性,其中ESO增韧效果最佳,其添加制备的复合材料断裂伸长率及缺口冲击强度分别提高了154.23%和65.53%,GL增韧效果最差,ATBC增韧后复合材料力学强度和模量最高。FTIR分析表明,ATBC和ESO可与PLA发生一定相互作用,使C-O键红外吸收峰位增大,其增韧后复合材料吸水率下降。ESO添加提高了TD/PLA复合材料的维卡软化点和热稳定性。SEM图片显示,TD/PLA/ESO复合材料断面粗糙,ESO分散较均匀,与PLA部分相容,而TD/PLA/GL复合材料断面出现严重相分离结构。该研究结果可为进一步探索聚乳酸基茶塑复合材料制备及应用提供试验数据和理论参考。     

Preparation and properties of biocomposites composed of epoxidized soybean oil,tannic acid,and microfibrillated cellulose

As a new biobased epoxy resin system, epoxidized soybean oil (ESO) was cured with tannic acid (TA) under various conditions. When the curing conditions were optimized for the improvement of the thermal and mechanical properties, the most balanced properties were obtained when the system was cured at 210°C for 2 h at an epoxy/hydroxyl ratio of 1.0/1.4. The tensile strength and modulus and tan δ peak temperature measured by dynamic mechanical analysis for the ESO–TA cured under the optimized condition were 15.1 MPa, 458 MPa, and 58°C, respectively. Next, we prepared biocomposites of ESO, TA, and microfibrillated cellulose (MFC) with MFC contents from 5 to 11 wt % by mixing an ethanol solution of ESO and TA with MFC and subsequently drying and curing the composites under the optimized conditions. The ESO–TA–MFC composites showed the highest tan δ peak temperature (61°C) and tensile strength (26.3 MPa) at an MFC content of 9 wt %. The tensile modulus of the composites increased with increasing MFC content and reached 1.33 GPa at an MFC content of 11 wt %. Scanning electron microscopy observation revealed that MFC was homogeneously distributed in the matrix for the composite with an MFC content of 9 wt %, whereas some aggregated MFC was observed in the composite with 11 wt % MFC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Bio-based Epoxy Resins from Epoxidized Plant Oils and Their Shape Memory Behaviors

In this study, bio‐based epoxy materials containing functionalized plant oil, such as epoxidized soybean oil (ESO) and epoxidized linseed oil (ELO), were processed with 4‐methylhexahydrophthalic anhydride (MHPA) as a curing agent. In the presence of tetraethylammonium bromide, the curing reaction of epoxidized plant oil and MHPA proceeded at 130 °C to give transparent plant oil‐based epoxy materials. The resulting bio‐based epoxy materials exhibited relatively soft and flexible characters, due to the aliphatic chains of plant oil. The thermal and mechanical properties of the ESO/MHPA polymers depended on the feed molar ratio of anhydride to oxirane. The mechanical properties such as tensile strength and Young's modulus of the ELO/MHPA polymer increased, compared with those of the ESO/MHPA polymer. The glass transition temperature of the ELO/MHPA polymer was higher than that of the ESO/MHPA polymer, because of the high oxirane number of ELO. Furthermore, the ELO/MHPA polymer showed excellent shape memory property.     

Effect of epoxy resin on morphology and physical properties of PVC/organophilic montmorillonite nanocomposites

Poly(vinyl chloride)/organophilic montmorillonite (PVC/OMMT) nanocomposites were prepared by means of melt blending. A liquid epoxy resin was used to aid PVC chains in intercalating into silicate layers. The effects of the preparation methods and epoxy resin contents on the melt intercalation of PVC were investigated. The morphology development, mechanical properties and optical properties of the PVC/OMMT composites were tested as functions of epoxy resin content and OMMT content. Wide‐angle X‐ray diffraction, transmission electron microscopy and scanning electron microscopy were used to characterize the morphology of the resulting composites. After being pretreated by the epoxy resin, the OMMT layers were largely intercalated into the PVC matrix, and even exfoliated at high epoxy resin content. The addition of epoxy resin led to a decrease in optical clarity of the composites but improved the processing stability, as indicated by yellowness index and haze measurement. However, the optical clarity of the composites containing 4 phr of epoxy resin (PVC/E‐OMMT) was improved by increasing the OMMT content, as shown by light transmission. Both the tensile strength and notched Izod impact strength of the PVC/E‐OMMT composites reached their maximum values when the OMMT content was 0.5 phr and the epoxy resin content was 2 phr. With further increase of the OMMT content and the epoxy resin content, the tensile strength decreased but was still higher than that of original PVC. The method of addition of epoxy resin had little effect on the physical properties but mainly influenced the morphology of PVC/OMMT nanocomposites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2184–2191, 2003     

Thermal and Mechanical Characterization of Epoxy Resins (ELO and ESO) Cured with Anhydrides

In this work we have developed polymeric materials from epoxidized vegetable oils in order to obtain materials with excellent mechanical properties for use as green matrix composites. Epoxidized soybean oil (ESO), epoxidized linseed oil (ELO) and different mixtures of the two oils were used to produce the polymers. Phthalic anhydride (17 mol%) and maleic anhydride (83 mol%) which has a eutectic reaction temperature of 48 °C were used as crosslinking agents while benzyl dimethyl amine (BDMA) and ethylene glycol were used as the catalyst and initiator, respectively. The results showed that samples 100ELO and 80ELO20ESO could be used as a matrix in green composites because they demonstrated good mechanical properties.     

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.     

Development of Novel Bio-Based Soybean Oil Epoxy Resins as a Function of Hardener Stoichiometry

Bio-based epoxy materials were prepared from epoxidized soybean oil (ESO) with an anhydride-curing agent. Variation of anhydride/epoxy ratio (R) was found to have significant effect on the resulting properties of the materials. The properties were studied and compared by dynamic mechanical analysis (DMA), izod impact, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The glass transition temperature reaches the maximum at stoichiometric ratio related to the cross-link density of the formed networks. These materials are thermally stable but exhibit a rapid decrease as the anhydride/epoxy ratio was increased.     

Effect of epoxidized soybean oil on mechanical properties of woven jute fabric reinforced aromatic and aliphatic epoxy resin composites

A systematic study was performed to describe the effect of epoxidized soybean oil (ESO) on storage modulus, glass transition temperature (T _g) and mechanical properties in epoxy resin composites reinforced by jute fabric. In addition to aromatic diglycidylether of bisphenol‐A (DGEBA) resin, a glycerol (GER)‐and a pentaerythritol (PER)‐based aliphatic resin was applied as base resin, which can be also synthesized from renewable feedstock. Based on strip tensile test results, the usual alkali treatment of jute fabric was avoided. By increasing the ESO‐content in aliphatic composites the T _g increases, whereas in case of DGEBA, it decreases. The results indicate that although ESO has a significant softening effect, the jute fiber‐reinforced DGEBA composite can be replaced without significant compromise in mechanical properties by a potentially fully bio‐based composite consisting of 25 mass% ESO‐containing aliphatic PER‐reinforced by jute fibers. POLYM. COMPOS., 38:884–892, 2017. © 2015 Society of Plastics Engineers     

Mechanical properties and morphology of epoxidized soyabean‐oil‐modified epoxy resin

Epoxidized soyabean oil (ESO) has been used to toughen epoxy resin cured with an ambient temperature hardener. The ESO was prepolymerized before blending with epoxy resin to obtain modified networks having various concentrations of ESO. The modified networks were also made by blending the ESO with epoxy resin by a one‐stage process. All the modified networks were characterized for their thermal, flexural and impact properties, and compared to the parent epoxy network. The optimum properties were obtained at 20 parts per hundred grams of resin (phr) of ESO. The impact behaviour is explained in terms of morphology observed by scanning electron microscopy. © 2001 Society of Chemical Industry     

Cationic UV-cured coatings containing epoxidized soybean oil initiated by new onium salts containing tetrakis(pentafluorophenyl)gallate anion

Different formulations containing epoxidized soybean oil (ESO) and a commercial cycloaliphatic epoxy resin (UVR6110) were cured by onium tetrakis(pentafluorophenyl)gallate (Gallate) on steel panels. The resulting coatings were clear and their mechanical properties were tested by the Sward hardness test, cross-hatch tape adhesion test and MEK double rub test. The new initiators have the advantage of good solubility, high reactivity, and the production of colorless coatings. The best formulations obtained contain 50% ESO, 50% UVR6110, and 0.5% silwet if sulfonium gallate is used as initiator, and 60% ESO, 40% UVR6110, and 0.5% silwet if iodonium gallate is the initiator. Center for Photochemical Sciences, Bowling Green, Ohio 43403.     

Biobased cyanate ester composites with epoxidized soybean oil and in situ generated nano‐silica

Biobased cyanate ester (CE) nanocomposites have been prepared from renewable resource, epoxidized soybean oil (ESO) and in situ generated nano‐silica via sol–gel process. The isothermal curing process was investigated by differential scanning calorimetry (DSC) and rheometry. The results indicate that the incorporation of silica accelerates the reaction at the beginning stage of curing process but descends the final isothermal curing conversion. The morphological study of nanocomposites by scanning electron microscope and transmission electron microscope suggests that the silica exists in the forms of both nanoparticles and silica networks, while the diameter of ESO‐rich phase diminished with the increase of silica loading. In addition, the thermal–physical and mechanical properties were evaluated by dynamic mechanical analysis, thermogravimetric analysis, and tensile mechanical test. The biobased CE nanocomposites show effectively improved properties compared to the systems without nano‐silica. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.     

Improved mechanical and thermal properties of bamboo–epoxy nanocomposites

Natural fiber‐reinforced hybrid composites based on bamboo/epoxy/nanoclay were prepared. Ultrasound sonication was used for the dispersion of nanoclay in the bamboo–epoxy composites. The morphology of bamboo–epoxy nanocomposites was investigated by using scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction. The results show that there exists an optimum limit in which the mechanical properties of composites improved by continuously increasing the nanoclay content. The tensile and flexural strength of bamboo–epoxy nanocomposites with 3 wt% nanoclay increased by 40% and 27%, respectively, as compared to pure composites. The highest value of impact strength was obtained for 1 wt% nanoclay content bamboo–epoxy nanocomposites. The enhanced impact strength of bamboo–epoxy nanocomposites was one of the key advantages brought by nanofiller. The results show that incorporation of nanoclay substantially increases the water resistance capability and thermal stability of bamboo–epoxy nanocomposites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Biobased nanocomposites from clay modified blend of epoxidized soybean oil and cyanate ester resin

Novel bio-based nanocomposites were prepared by blending surface modified natural clay with epoxidized soybean oil (ESO) and cyanate ester resin (CE). A convenient method was employed to modify the attapulgite (ATT) clay by adsorbing the poly(ethylene glycol) diglycidyl ether (PEGDE) onto the clay surface, which was confirmed by the appearance of a new peak of infrared spectroscopy due to hydrogen bonding and chelation. Thermogravimetic analysis (TGA) showed that the amount of PEGDE adsorbed on ATT was influenced by PEGDE concentration in acetone solution. Scanning electron microscope (SEM) and transmission electron microscope (TEM) results showed that nanoscaled ATT dispersed well in the blend of epoxidized soybean oil (ESO) before and after curing. The thermal-physical and mechanical properties were evaluated by dynamic mechanical analysis (DMA), TGA and tensile mechanical test. The nanocomposites showed higher glass transition temperature and modulus, and the tensile strength of the nanocomposites was reinforced as compared to that of ESO/CE blends.     

Comparison of curing agents for epoxidized vegetable oils applied to composites

Interest in polymers from renewable sources, as alternatives to petroleum‐based polymers, remains strong; however, their performance must be acceptable. To improve performance of epoxidized vegetable oils (EVO) in composite matrix applications, five amine curing agents were evaluated and compared with an anhydride agent used previously. Curing agents were tested in matrices for composites containing a petroleum‐based epoxy resin plus 0% or 30% epoxidized oil from canola (ECO) and soybean (ESO). The two amines with the highest glass transition temperature, determined by differential scanning calorimetry, were selected for characterization by dynamic mechanical analysis; bis (p‐aminocyclohexyl) methane (PACM) showed the highest performance. Amine: epoxy ratios 0.6 to 1.6 were then evaluated; ratios of 0.8 and 1.0 showed superior performance. E‐glass fiber reinforced composites with PACM/EVO showed thermal and mechanical performance slightly lower than the composites with 0% EVO and comparable with those of the anhydride curing agent. Therefore, ECO or ESO blended with petroleum‐based epoxy resins cured with PACM are recommended for its application in E‐glass reinforced composites. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Nanoclay and long-fiber-reinforced composites based on epoxy and phenolic resins

In this study, high-performance thermoset polymer composites are synthesized by using both long fibers and nanoclays. Epoxy and phenolic resins, the two most important thermoset polymers, are used as the polymer matrix. The hydrophobic epoxy resin is mixed with surface modified nanoclay, while the hydrophilic phenolic resin is mixed with unmodified raw nanoclay to form nanocomposites. Long carbon fibers are also added into the nanocomposites to produce hybrid composites. Mechanical and thermal properties of synthesized composites are compared with both long-fiber-reinforced composites and polymer- layered silicate composites. The optimal conditions of sample preparation and processing are also investigated to achieve the best properties of the hybrid composites. It is found that mechanical and thermal properties of epoxy and phenolic nanocomposites can be substantially improved. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚苯胺改性蒙脱土/天然橡胶纳米复合材料的制备与性能

采用原位聚合法制备了聚苯胺质量分数为20% 的聚苯胺改性蒙脱土,并以此作为增强剂利用机械混炼法制备了聚苯胺改性蒙脱土( PANI － MMT) /天然橡胶( NR) 纳米复合材料。使用X 射线衍射仪、傅里叶变换红外光谱仪及扫描电镜等对PANI － MMT 和PANI － MMT/NR 复合材料的结构进行了表征,并考察了PANI － MMT/NR 复合材料的力学性能。结果表明,PANI － MMT/NR 复合材料形成了插层型纳米结构; 与普通的有机蒙脱土/NR 复合材料相比,PANI － MMT/NR 复合材料的力学性能明显提高,PANI － MMT 添加质量为20 份时其力学性能达到最好,并超过了添加40 份炭黑N 660 的NR 的力学性能。     

Solid freeform fabrication of epoxidized soybean oil/epoxy composites with di‐, tri‐, and polyethylene amine curing agents

Soybean oil/epoxy‐based composites are prepared by solid freeform fabrication (SFF) methods. SFF methods built materials by the repetitive addition of thin layers. The mixture of epoxidized soybean oil and epoxy resin is modified with di‐, tri‐, or polyethylene amine gelling agent to solidify the materials until curing occurs. The high strength and stiffness composites are formed through fiber reinforcement. E‐glass, carbon, and mineral fibers are used in the formulations. The type of fiber affects the properties of the composites. It was found that a combination of two types of fibers could be used to achieve higher strength and stiffness parts than can be obtained from a single fiber type. In addition, the effects of curing temperature, curing time, and fiber concentration on mechanical properties of composites are studied and reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 356–363, 2004     

Functionally Graded Polyurethane/Cellulose Nanocrystal Composites

The preparation and investigation of functionally graded polymer nanocomposites, which have a concentration gradient of cellulose nanocrystals (CNCs) along one direction, is reported here. As a test bed, a series of nanocomposites consisting of a thermoplastic polyurethane (PU) and 0–15% w/w CNCs is prepared via solvent casting and the mechanical properties of films of these materials are characterized by dynamic mechanical analyses and tensile tests. The formation of graded materials is accomplished by lamination of films with varying CNC content. The processing conditions are optimized to achieve intimate fusion of the individual layers. The elimination of internal interfaces is evidenced by an elongation at break of up to 500%. In order to explore potential applications of graded PU/CNC nanocomposites, structure‐dependent actuation in response to water is demonstrated in a bioinspired architecture. In addition, the damping behavior of cylindrical shaped composites is investigated by way of compression tests. The results show that functionally graded PU/CNC composites show good damping behavior over a much larger range of forces than the neat PU or the homogeneous nanocomposites.