Two kinds of rosin derivatives, (2-hydroxy-3-(methacryloyloxy)propyl 7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,4b,5,6,10,10a-decahydrophenanthrene-1-carboxylate) (HMPIDDC) and (((7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl)methyl)azanediyl)bis(2-hydroxypropane-3,1-diyl)bis(2-methylacrylate) (IDOMAHM) were synthesized under mild and easy to implement conditions. The two derivatives were employed as the rigid monomers to copolymerize with acrylated epoxidized soybean oil (AESO), as so to improve the performance of the cured resins. The chemical structures of HMPIDDC and IDOMAHM were confirmed by nuclear magnetic resonance (NMR) and Fourier Transform Infrared (FT-IR) before copolymerization. The curing behaviors of pristine AESO, AESO/HMPIDDC blend, and AESO/IDOMAHM blend were monitored by differential scanning calorimetry (DSC). Moreover, the thermal and mechanical properties of the cured resins were evaluated by universal mechanical testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The results demonstrated that after the introduction of HMPIDDC and IDOMAHM, the glass transition temperature and mechanical properties of the copolymerized resin were significantly increased. In one word, HMPIDDC and IDOMAHM showed dramatic potential to be used as bio-based compounds to improve the properties of soybean-oil based thermosets.

•Benzoxazine (BZ-F) with high purity was synthesized from bio-based furfurylamine.•Oxygen atom in furan ring led to more hydrogen bond in pBZ-F system.•pBZ-F system demonstrated higher performance.A high performance polybenzoxazine derived from bio-based furfurylamine was synthesized in an efficient and straightforward way. For comparison, its petroleum-based analogue was also prepared from 4, 4-diaminodiphenylmethane (DDM). The chemical structures of the precursors were confirmed by Nuclear Magnetic Resonance Spectroscopy (1H-NMR and 13C-NMR) and Fourier Transform Infrared Spectroscopy (FT-IR). After the curing reaction was investigated by Differential Scanning Calorimetry (DSC) and FT-IR in detail, the thermal and mechanical properties of the cured resins were studied by Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). Results demonstrated that the polybenzoxazine based on furfurylamine (BZ-F) possessed higher glass transition temperature (270 °C) and better thermal stability associated with higher charring ability when compared with the one (BZ-DDM) derived from DDM, which might be attributed to the stronger hydrogen bonding interaction in the BZ-F system and the post-curing reaction on furan ring above 280 °C. In this paper, the hydrogen bonding effect on the properties of polybenzoxazine has been especially studied, which might give us a guidance to design and synthesize the polybenzoxazine with high performance.Download high-res image (121KB)Download full-size image

•We prepared a series of novel bio-based antibacterial polymer films.•The antibacterial polymer films exhibited well inhibitory activity against E. coli and S. aureus, especially for E. coli.•We developed potential antibacterial materials with higher performance through a more environmental friendly method.Bio-based anti-bacterial cross-linked films with superior properties were prepared via UV-thermal induced thiol-ene “click” reaction of diallyl itaconate (DAI), eugenol allyl ether (EAE) with trimethylolpropane tris (3-mercaptopropionate). DAI and EAE were made from one-step reaction of itaconic acid and eugenol with allyl bromide, respectively. The curing behaviors studied by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and gel content measurement illustrated that UV-thermal dual cure technology made the thiol-ene reaction more completely and produced films with higher performance compared with UV cure technology. The investigation of the thermal and mechanical properties of the cross-linked films by DSC, thermogravimetric analysis (TGA) and tensile test indicated that the glass transition temperature, tensile strength and modulus of the films were significantly improved after introducing DAI, and all the films exhibited similar and high thermal stability. Meanwhile, these bio-based polymer films showed excellent efficiency in killing common bacterias, e.g. S. aureus and E. coli in the dynamic shake test.

Two kinds of UV-curable monomers (EM2G and EM3G) were synthesized from eugenol via a thiol–ene reaction. Their chemical structures were confirmed by FT-IR, 1H-NMR and 13C-NMR before they were employed to copolymerize with acrylated epoxidized soybean oil (AESO). Bio-based UV curable resins were prepared and their thermal and mechanical properties were investigated by tensile testing and dynamic mechanical analysis (DMA). Their coating properties on tinplate were also studied. The results showed that the tensile strength, tensile modulus and glass transition temperatures of the cured AESO were significantly improved after the introduction of eugenol-based monomers. In addition, the UV-cured resins could be well coated on the surface of tinplate and good coating properties, such as hardness, flexibility, adhesion, solvent resistance and water absorption were demonstrated.

•A crosslink agent IG derived from itaconic acid with low viscosity and high UV reactivity was synthesized.•IG together with HMP was used as crosslink agents to strengthen AESO and the UV-curable coatings without any solvent were prepared.•The coatings films exhibited good solvent resistance performance.A UV curable unsaturated monomer (IG) was synthesized from itaconic acid and glycidyl methacrylate (GMA). After its chemical structure was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (1H NMR and 13C NMR), IG was used as a crosslink agent to copolymerize with acrylated epoxidized soybean oil (AESO) and a series of UV-cured coatings were prepared. Their thermal and mechanical properties as well as the coating properties on tinplate were investigated. Results demonstrated that not only the mechanical properties such as tensile strength and modulus, but also the coating performances in terms of hardness, flexibility, adhesion and solvent resistance of the cured AESO were increased significantly with the increasing content of IG. The synthesized bio-based IG showed great potential to improve the coating properties of AESO.

A bio-based shape memory epoxy resin (DGEAPA) was synthesized from rosin to achieve the sustainability of shape memory epoxy resin, and its chemical structure was determined by FTIR and 1H NMR. For comparison, a petroleum-based epoxy, diglycidyl ester of terephthalic acid (DGT) having one benzene ring, was also synthesized. The properties, including thermal and mechanical properties, as well as shape memory properties of the epoxy resins cured with poly(propylene glycol)-bis (2-aminopropyl ether) (D230), were studied by differential scanning calorimeter, dynamic mechanical analysis, thermogravimetric analysis, tensile test, and U-type shape memory test. The effect of the stoichiometric ratio nDGEAPA/nDGT on the properties was studied as well. The thermal and mechanical properties, including thermal stability, glass transition temperature, tensile strength, and modulus of the cured epoxy systems, were found to be increased with DGEAPA incremental content, and the cured neat rosin-based epoxy system exhibited the highest properties. Both the cured rosin-based epoxy and the cured DGEAPA showed significant shape memory performance. Meanwhile, the rosin ring structure made the cured rosin-based epoxy systems display excellent shape recovery fixity, while small lower shape recovery and shape recovery rate relative to the cured neat DGT system. Therefore, the rosin-based epoxy resin has a great potential in the shape memory material applications.

•The composition of copolyesters determined by the feed molar ratio of CHDM to DMFD.•The toughness of PEF could be efficiently improved by the introduction of CHDM units.•The oxygen and carbon dioxide barrier properties of the copolymers were much higher than PET homopolymers.•An expectable method is provided to improve the toughness of PEF without sacrificing its Tg and barrier properties.A series of poly(ethylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate)s (PECFs) with different compositions were synthesized from 2,5-Furandicarboxylic acid (FDCA), 1,4-cyclohexanedimethylene (CHDM) and ethylene glycol (EG). Their chemical structures, composition and sequence distribution were determined by FT-IR, 1H NMR and 13C NMR. The composition of the resulted polyesters could be controlled by the feed mole ratio of CHDM to dimethyl furan-2,5-dicarboxylate (DMFD). And for all the copolyesters, the degree of randomness (R) was close to 1, indicating their randomness. Their thermal and mechanical properties were investigated by Differential Scanning Calorimeter (DSC) and tensile testing, results showed that the crystallizability, tensile modulus and strength of PECFs were decreased with the increasing content of CHDM at first (0–59%), and with the introduction of more CHDM (76–100%) units, they were increased accordingly. However the elongation at break was changed contrarily. The barrier properties study demonstrated that although the O2 and CO2 permeability of PEF was increased by the introduction of CHDM, PECF-32 and PECF-76 still showed excellent barrier properties, which were better or comparable to those of PEN and PEI.A serials of bio-based polyesters (PECFs) in full composition range were synthesized from CHDM, EG and FDCA. Considering the crystallization ability and toughness as well as O2/CO2 permeability of PECFs, the copolyesters PECF-76 might be the promising substitute for PET in packaging industry.

A series of bio-based polyesters were synthesized by melt polycondensation of itaconic acid with diols and glycerol without VOC emission. Their chemical structures were confirmed by FT-IR and 1H-NMR before they were made to copolymerize with acrylated epoxidized soybean oil (AESO). The thermal and mechanical properties of the resulting thermosets were investigated by differential scanning calorimetry (DSC), tensile testing and dynamic mechanical analysis (DMA). Their coating properties on tinplate and glass plate were also studied. Results showed that the tensile strength, modulus, glass transition temperatures and bio-based content of the AESO-based thermosetting resins were significantly improved after the introduction of the synthesized polyesters. In addition, the modified AESO systems could be well coated on the surface of tinplate and glass plate and good coating properties such as hardness, flexibility, adhesion, solvent resistance and water absorption were demonstrated. They showed great potential for applications as coatings, adhesives and composites.

A bio-based epoxy monomer, diglycidyl ester of 2,5-furandicarboxylic acid (DGF) was synthesized for the first time from the renewable 2,5-furandicarboxylic acid (FDCA). For comparison study, its petroleum-based counterpart, diglycidyl ester of terephthalic acid (DGT) was also prepared. Their chemical structures were confirmed in detail by 1H NMR, 13C NMR and FT-IR before they were cured by methylhexahydrophthalic anhydride (MHHPA) and poly(propylene glycol)bis(2-aminopropyl ether) (D230), respectively. The curing behaviors were investigated using differential scanning calorimetry (DSC). The thermal mechanical properties and thermal stabilities of the cured resins were evaluated using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). Results showed that DGF displayed higher curing activity, elevated glass transition temperature and similar mechanical properties compared with those of the cured DGT. This study indicated that FDCA had a huge potential to replace the petroleum-based terephthalic acid in the synthesis of epoxy resins with satisfactory performance.

•We synthesized a series of fully bio-based unsaturated polyester resins.•High bio-based content waterborne UV-curable coatings were prepared.•The coatings exhibited excellent adhesion and flexibility.A series of bio-based unsaturated polyesters was synthesized by melt polycondensation of itaconic acid with 1,4-butanediol and glycerol. Their chemical structures were confirmed by FT-IR, 1H NMR, acid and hydroxyl values. Waterborne UV curable dispersion coatings based on these polyesters and acrylated epoxidized soybean oil (AESO) were formulated. The average particle size and their stability before curing as well as the coating properties after curing, including adhesion, flexibility, pencil hardness and solvent resistance, were investigated. Results demonstrated that the glycerol segment in the polyesters together with AESO led to the excellent coating properties in terms of highest grade of adhesion (5B), 0T flexibility, pencil hardness of 5H and excellent solvent resistance (no appearance change after 250 double rubs with ethanol and acetone). This work provided us the coating systems combining the merits of being bio-based, UV-curable and water dispersible.

The utilization of soybean oil-based UV coatings depends on the introduction of petroleum-based comonomers or crosslink agents. Thus, in this paper, a bio-based crosslink agent (GACA) for UV curable coatings was synthesized from gallic acid and its chemical structure was confirmed by FT IR, 1H NMR and 13C NMR. Crosslinked networks with high biobased content of more than 88% were obtained after co-photopolymerization between acrylated epoxidized soybean oil (AESO) and GACA. The thermal, mechanical and coating properties of these GACA crosslinked AESO networks were investigated and a commonly used crosslink agent triallyl isocyanurate (TAIC) was used as the control. GACA exhibited more functional groups and better copolymerization with AESO than TAIC, resulting in the higher gel content, crosslink density, tensile strength and modulus as well as much better coating properties (reflected by the higher pencil hardness, better wear resistance and adhesion) of GACA crosslinked AESO networks than TAIC crosslinked AESO networks. These results indicated that GACA exhibited great potential to replace petroleum-based crosslink agents such as TAIC, and high-performance soybean oil-based UV-cured coatings with high biobased content could be achieved after introducing GACA.

A phosphorus-containing bio-based epoxy resin (EADI) was synthesized from itaconic acid (IA) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). As a matrix, its cured epoxy network with methyl hexahydrophthalic anhydride (MHHPA) as the curing agent showed comparable glass-transition temperature and mechanical properties to diglycidyl ether in a bisphenol A (DGEBA) system as well as good flame retardancy with UL94 V-0 grade during a vertical burning test. As a reactive flame retardant, its flame-resistant effect on DGEBA/MHHPA system as well as its influence on the curing behavior and the thermal and mechanical properties of the modified epoxy resin were investigated. Results showed that after the introduction of EADI, not only were the flame retardancy determined by vertical burning test, LOI measurement, and thermogravimetric analysis significantly improved, but also the curing reactivity, glass transition temperature (Tg), initial degradation temperature for 5% weight loss (Td(5%)), and flexural modulus of the cured system improved as well. EADI has great potential to be used as a green flame retardant in epoxy resin systems.

A novel itaconic acid (IA) based epoxy resin with curable double bonds (EIA) was synthesized by the esterification reaction between IA and epichlorohydrin (ECH). Its chemical structure was confirmed in detail by FT-IR, 1H-NMR and ESI-ION TRAP MS before being cured by methyl hexahydrophthalic anhydride (MHHPA). In order to manipulate the properties of the cured resin, divinyl benzene (DVB) and acrylated epoxidized soybean oil (AESO) were employed here to act as comonomers. The results demonstrated that EIA showed a higher epoxy value of 0.625 and higher curing reactivity toward MHHPA compared with the commonly used diglycidyl ether of bisphenol A (DGEBA). The glass transition temperature, tensile strength, flexural strength and modulus of the cured EIA without comonomers were 130.4 °C, 87.5 MPa, 152.4 MPa and 3400 MPa, respectively, which were comparable or better than those of DGEBA cured by the same curing agent. After being copolymerized with DVB or AESO, the properties of the cured EIA could be regulated further. The results indicated that EIA has great potential to replace the petroleum-based thermosetting resin, such as DGEBA.

Two kinds of rosin acid derivatives were synthesized to serve as the rigid monomers to copolymerize with acrylated epoxidized soybean oil (AESO). Full bio-based thermosetting resins with satisfactory properties were then prepared. For comparison, petroleum-based divinylbenzene (DVB) was also used to copolymerize with the same AESO. The chemical structures of the synthesized rosin derivatives were confirmed by 1H NMR, 13C NMR and FT-IR before polymerization. The mechanical and thermal properties of the resulting thermosets were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). Results demonstrated that the glass transition temperatures, tensile strength and modulus of the cured AESO were significantly improved after copolymerization with the rosin derivatives. The rosin acid derivatives showed great potential to replace petroleum-based rigid compounds for preparing soybean oil-based thermosets. The important information about how to design and synthesize more renewable thermosets with satisfactory properties was provided in this study.

A bio-based epoxy monomer (GA-II) was synthesized from renewable gallic acid. The aromatic group contained made it capable of being absorbed onto the surface of graphene via strong π–π interactions, which was proven by Raman spectra and UV spectra. The GA-II anchored graphene was easily homogeneously dispersed in the epoxy resin. After solidification, the graphene/epoxy composites demonstrated superior performances in terms of good mechanical properties, excellent thermal conductivity, as well as high electrical conductivity. With the addition of only 2 wt% GA-II/graphene, the tensile strength, tensile modulus, flexural strength and flexural modulus of the composites were improved by 27%, 47%, 9% and 21%, respectively. The thermal and electrical conductivities were also improved by 12-fold (from 0.15 to 1.8 W m−1 K−1) and 8 orders (from 7.0 × 10−15 to 3.28 × 10−5 s cm−1), respectively. This work provided us with an environmentally friendly agent with high efficiency for graphene dispersion and demonstrated an efficient method for fabricating epoxy/graphene composites with superior properties.

In view of sustainable development and environmental protection, renewable itaconic acid was used to synthesize a bio-based curing agent for soy-based adhesives. The bio-based curing agent, i.e., itaconic acid-based polyamidoamine-epichlorohydrin resin (IA-PAE), was characterized by RSV and 1H-NMR. Results showed that IA-PADA and IA-PAE had much lower molecular weights than commercial PAE (C-PAE). Both N-(3-chloro-2-hydroxypropyl) groups and azetidinium rings of IA-PAE could perform as functional groups in IA-PAE modified soy flour adhesive (IA-PAE-SF). The pH values affected the viscosities of IA-PAE-SF adhesives significantly but had little effect on the wet strengths. Wet strength of IA-PAE-SF on plywood (0.95 MPa) was comparable to that of C-PAE-SF and met the requirements of Chinese National Standards for type-II applications. Cross-linking networks were formed during hot-pressing process and thus, improved water resistance of IA-PAE-SF on plywood. Measurement of water-insoluble solid content of cured adhesives and observation of SEM confirmed the formation of cross-linking networks in cured IA-PAE-SF.

A bio-based epoxy monomer (GA-II) was synthesized from renewable gallic acid. The aromatic group contained made it capable of being absorbed onto the surface of graphene via strong π–π interactions, which was proven by Raman spectra and UV spectra. The GA-II anchored graphene was easily homogeneously dispersed in the epoxy resin. After solidification, the graphene/epoxy composites demonstrated superior performances in terms of good mechanical properties, excellent thermal conductivity, as well as high electrical conductivity. With the addition of only 2 wt% GA-II/graphene, the tensile strength, tensile modulus, flexural strength and flexural modulus of the composites were improved by 27%, 47%, 9% and 21%, respectively. The thermal and electrical conductivities were also improved by 12-fold (from 0.15 to 1.8 W m−1 K−1) and 8 orders (from 7.0 × 10−15 to 3.28 × 10−5 s cm−1), respectively. This work provided us with an environmentally friendly agent with high efficiency for graphene dispersion and demonstrated an efficient method for fabricating epoxy/graphene composites with superior properties.