Conventional glass fiber reinforced composites (GFRCs) are usually difficult to degrade and the matrix usually exhibit low Tg. To address this dilemma, a degradable catalyst-free self-healing vitrimer matrix with a high Tg was fabricated using turpentine-derived terpene maleic acid (TMA) as a curing agent and epoxidized menthane diamine (EMDA) with a tertiary amine structure as an epoxy resin. Due to the introduction of a rigid terpene ring skeleton of turpentine, EMDA-TMA vitrimer exhibits a Tg of up to 201.8 degrees C. Due to the tertiary amine groups in the EMDA-TMA, the vitrimer can achieve self-healing and recycling properties by dynamic transesterification reaction without the addition of catalysts. More importantly, the EMDA-TMA-GF composite prepared using EMDA-TMA vitrimer as a matrix also shows a high Tg (223.6 degrees C), and excellent mechanical properties. In addition, under the synergistic action of potassium hydroxide (KOH) and ethanolamine (EA), the EMDA-TMA-GF composite can be rapidly degraded by a KOH/EA solution to realize non-destructive recovery of glass fibers.

Designing degradable foams with excellent Joule heating and electromagnetic interference (EMI) shielding properties are crucial for protecting both the environment and low-temperature sensitive electronic devices. In this work, we used 1,3-diaminopropane carbamate (DPC) as a latent foaming-curing agent to prepare soft-hard tunable, degradable bio-based epoxy foams through one-step chemical foaming method. Subsequently, using F3 foam with outstanding reversible compressibility as the substrate, we developed a silver-plated foam, F3A3, with predominantly reflective and high EMI shielding performance via silver mirror reaction. The silver-plated foam F3A3 exhibited an electromagnetic interference shielding effectiveness (EMI SE) of 76.37 dB in the X-band (8.2-12.4 GHz), achieving a shielding efficiency as high as 99.99999%. Additionally, under an input voltage of 1.0 V, the surface saturation temperature of F3A3 rapidly increased from room temperature to 104.0 degrees C and demonstrated excellent stability and durability in low-voltage Joule heating. Due to the presence of dynamic ester bonds and tertiary amine structures in the F3A3 foam, it exhibited catalyst-free self-healing capability. These superior properties make the silver-plated foam highly promising for applications in military equipment, aerospace, and wearable electronic devices.

Polybenzoxazines (PBozs) are regarded as prime candidates as low dielectric matrixes. However, the fabrication of high-performance PBozs that combines low dielectric property with high thermal stability using sustainable resources as the starting raw materials remains a significant challenge. In this work, we constructed a novel main-chain benzoxazine (Boz) oligomer from natural essential oil-derived compounds (eugenol and p-menthane diamine) to fulfill the principles of green chemistry. To enhance their low dielectric properties, polar C-Si unit on the main-chain and cellular structure of polyoctahedral silsesquioxanes (POSS) as the cross-linkers were introduced in PBoz-POSS composites. The obtained composites demonstrated excellent thermal stability, mechanical property, and with remarkable low dielectric constants. Coupled with their exceptional hydrophobicity and heat resistance, these materials are promising matrixes for low dielectric application in contemporary electronic industries.

For the first time, a novel porous organic polymer (POP), namely Cin-POP, was constructed under normal temperature and pressure using less toxic basic fuchsin and natural cinnamic acid. Cin-POP was synthesized through the diazo-coupling reaction between the diazonium salts of basic fuchsin and cinnamic acid. The FT-IR spectra and XPS analysis prove the successful construction of the Cin-POP, and the BET analysis demonstrates the high-surface-area (166.42-202.56 m(2) g(-1)) and suitable pore sizes (11.00-18.63 nm). Owing to the advantages of porous structures, abundant aromatic groups, good thermal stability, and good dispersity, Cin-POP exhibits remarkable adsorption rates and capacities towards polyphenols, including procyanidine and rutin. Especially for procyanidine, the extraction efficiency can arrive at nearly 98.1 % after 2.5 min adsorption, and the pseudo-second-order rate constant (k(2)) of Cin-POP is 0.0257 g mg(-1) min(-1). The maximum adsorption capacities of Cin-POP towards procyanidine and rutin are 2500.00 mg g(-1) and 1814.83 mg g(-1), outpacing all reported adsorbents. In addition, Cin-POP can selectively adsorb polyphenol among the mixtures of polyphenols and alkaloids. More importantly, Cin-POP can be used for polyphenols separation from complex cinnamon extract. All the above advantages make Cin-POP comparable porous adsorbent for polyphenol separation.

The preparation of carbon fiber reinforced polymers (CFRP) using vitrimer with hydroxyl ester bonds as matrix requires harsh degradation conditions. To solve this problem, tung oil-based triglycidyl ester (TOTGE) and 4-ami-nophenyl disulfide (APD) are cured to fabricate a TOTGE-APD vitrimer with a dual dynamic network of hy-droxyl ester and disulfide bonds. The TOTGE-APD vitrimer exhibits a low dynamic bond exchange activation energy (66.51 kJ/mol) due to the introduction of disulfide bonds and can achieve stress relaxation at 100 degrees C, thus exhibiting excellent self-healing and recycling properties. After crushing/remodeling, tensile strength of the remodeling sample can achieve 97.5% the original sample. Due to the disulfide and ester group in the vitrimer, CFRP prepared with TOTGE-APD vitrimer can be degraded in mercaptoehtanol, ethanolamine, and ethylene glycol, achieving multiple recycling.

Closed-loop recycling in the matrix resin and carbon fibers (CFs) of carbon fiber-reinforced polymers (CFRPs) is a major challenge. To solve this problem, herein, a closed-loop recyclable vitrimer matrix containing hydroxy-terminated hyperbranched polyesters (HBPs), rosin-derived fumaropimaric acid (FPA), and glycerol triglycidyl ether (GTE) is prepared. The FPA/GTE/HBP vitrimers exhibited excellent mechanical properties owing to the highly reactive hydroxy-terminated HBP and rigid FPA. The abundant hydroxyl groups of HBP catalyzed the dynamic transesterification reaction of the vitrimer network, resulting in self-healing and reprocessing properties. In addition, FPA/GTE/HBP−CF composites exhibited high mechanical strength and interlayer shear strength owing to the presence of HBP. FPA/GTE/HBP15−CF was degraded by ethylene glycol during the catalytic operation of the hydroxy-terminated HBP, and the degraded matrix could be closed-loop recycled. Scanning electron microscopy, Raman analysis, and tensile testing showed that the degradation reaction did not degrade the properties of the recycled CFs. This study presents an environmentally-friendly strategy for preparing closed-loop recyclable CFRPs.

The poor mechanical properties and disadvantages of catalysts limit the application of self-healing materials. To address these issues, catalyst-free self-healing bio-based polymers (AESO-EMPA polymers) with robust mechanical properties were prepared using epoxidized maleopimaric anhydride (EMPA) and aminated epoxidized soybean oil (AESO). The AESO-EMPA polymers are recyclable and exhibit self-healing and shape memory because of the dual-dynamic network of multiple H-bonds and dynamic ester bonds in the structure. Under the synergistic catalysis of the tertiary amines and hydroxyl groups originated from the polymers, the polymers in this study achieve network rearrangement without the need for additional catalysts. The polymers also exhibit excellent mechanical properties with a tensile strength of 29.1 ± 0.25 MPa and a Tg of 80.2 °C owing to the unique rigid backbone of rosin and the dual-dynamic network. The AESO-EMPA polymers can be used as reusable adhesives and exhibit excellent shear strength and repair rates.

In this study, we will report on the synthesis and application of efficient botanical agrochemicals from turpentine for sustainable crop protection. Two series of turpentine derived secondary amines were synthesized and identified by FT-IR, 1H NMR, 13C NMR, and HRMS. The herbicidal activities against Echinochloa crus-galli were evaluated. The potential toxicity of the synthesized compounds was tested by MTT cytotoxicity analysis. The effect of structure of the synthesized secondary amines and corresponding Schiff base compounds on their activities was investigated by quantitative structure-activity relationship (QSAR) study. All target products were found to be low toxicity, with similar or higher herbicidal activities than commercial herbicides diuron and Glyphosate. Results of QSAR study showed that a best four-descriptor QSAR model with R2 of 0.880 and Rloo2 of 0.818 was obtained. The four descriptors most relevant to the herbicidal activities are the min valency of a N atom, the max total interaction for a C-H bond, the relative number of aromatic bonds, and the min partial charge (Qmin).

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The molecule of the title compound, C17H17BrN2O5, assumes an E configuration, with the 5-bromo-2-hydroxyphenyl and benzohydrazide units located on opposite sites of the C=N double bond. The dihedral angle between the planes of the two benzene rings is 32.48 (15)°. The crystal structure is stabilized by intramolecular O—H...N and intermolecular N—H...O hydrogen bonds.