CONSTRUCTION AND BUILDING MATERIALS
·
2019
·
IF 4.046
Yihang Zhang,Miao He,Mingbiao Xu,Jianjian Song,Peng Xu,Xiaoliang Wang
Sepiolite fiber (HPS), as a cheap and environmentally friendly mineral fiber material, has good application value in toughening filler of oil well cement stone and is the best substitute for toxic asbestos material. However, due to the defects of conventional industrial HPS such as low purity, poor dispersion, it will produce great incompatibility with cement slurry, which will adversely affect its performance. In this paper, conventional industrial HPS was treated with activation modification. The changes of surface groups of sepiolite before and after modification and the actual dispersion effect in aqueous solution were studied by FTIR and dispersion state of aqueous solution. In addition, the effects of modified sepiolite fibers (H-HPS) and carbon fibers (C-Fibers) on oil well cement were also investigated. The mechanism of the micro-morphology of the toughened cement paste was analyzed. The results show that the dispersion and suspension of H-HPS in aqueous solution have been greatly improved. The rheological test results of cement paste also support the improvement. At the same time, the optimum mixing ratio of the two materials was screened out by synergistic study with C-Fibers. It was found that the composite fiber cement slurry system synthesized the advantages of the two kinds of fiber materials, and the toughening effect was obviously better than that of the modified cement paste with a single admixture. From the analysis of SEM, it can be seen that HPS in the composite fiber cement slurry system fills in micro-voids on the one hand, and forms a uniformly dispersed network structure on the other hand, The C-Fibers in the system can effectively dissipate the tensile energy of the fracture interface of cement paste by interacting with hydration products, thus reducing the filtration of cement paste and improving the bulk toughness of cement paste.
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Bo Yang,Jianyi Qin,Umar Wahid,Xibao Chen,Rui Cai,Zhongfu Zhao,Wei Liu,Chunqing Zhang
Many toughening strategies have been employed to address the inherent brittleness of epoxy resin (Ep), but at the cost of strength and modulus. Herein, a series of poly(arylene pyridine) copolymers (MTAP-X) were synthesized via superacid-catalyzed polyhydroxyalkylation and blended directly with epoxy precursors in varying ratios. Both MTAP-X copolymers and epoxy composites were characterized using 1H NMR, FT-IR, TGA, DSC, DMTA, SEM, and AFM, as well as mechanical and impact testing. The results demonstrate that the twisted aromatic molecular structures of MTAP-X, controlled by the m-terphenyl to p-terphenyl ratio, enhances both the toughness and mechanical properties of epoxy composites by increasing free volume and incorporating rigid biphenyl units. As the proportion of meta-terphenyl in triphenyls increases from 30% to 60%, MTAP-X copolymers significantly enhance the tensile strength, Young’s modulus and toughness of the epoxy composites. Although further increasing the meta-terphenyl content improves toughness, it compromises the mechanical strength of the epoxy composites. At an optimal loading of 7.5 wt % MTAP-50 copolymer, the KIC, GIC, impact strength, tensile strength, and Young’s modulus increase by 92.87%, 220.39%, 93.14%, 59.66%, and 46.61%, respectively, compared to pure Ep. The toughening mechanism is attributed to the ability of adjacent phenyl groups in the MTAP-X copolymers to rotate toward each other through σ-bonds, thereby increasing free volume. Additionally, strong interfacial interactions between the pyridine ring, suspended from the polymer backbone, and the Ep contribute to the toughening effect. The rigid copolymer backbone further reinforces the epoxy network, enhancing the overall strength and durability of the Ep.
研究领域:
高分子科学
·
材料工程
·
有机合成
·
复合材料
·
力学性能
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 34
·e52803
·
IF 3.057
Wei Zhang,Qingyin Wang,Gongying Wang,Shaoying Liu
The block copolymers PEF/PBAT were synthesized by copolymerizing ethylene 2,5-furandicarboxylate (EF) with totally biodegradable poly (butylene adipate-co-terephthalate) (PBAT). The copolymers' molecular chain structure, thermal properties, thermal stability, and mechanical properties were investigated, and the toughening mechanism was preliminarily studied via the micromorphology. The results revealed that the prepared block copolymers were amorphous, the thermal stability of PEF was improved, while the glass transition temperature decreased with the increase of PBAT content. PBAT was enhancing the tensile strength and elongation at break of PEF simultaneously. When the PBAT content was 25% (PEF/PBAT-25), the brittle-ductile transition occurred, with the tensile strength, Young's modulus and elongation at break of 72 MPa, 3210 MPa and 287%, respectively. The copolymers have broad application in the field of packaging materials.
研究领域:
高分子科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2011
·
IF 2.518
Bing Meng,Jingjing Deng,Qing Liu,Zhihua Wu,Wei Yang
Poly(butyl acrylate) was prepared by the free radical polymerization of butyl acrylate as an initiator in the presence of 2,2′-Azoisobu-tyronitrile (AIBN) and the average molecular weight , polydispersity and thermal stability were evaluated. PLA and PBA were melt blended using a Haake Rheometer, and the light transmission, thermal properties, dynamic rheological properties, mechanical properties , phase morphology of blends and toughening mechanism were investigated. Dynamic rheology, SEM and DSC results show that the PLA is partial miscible with PBA. The PBA component improved the crystallization ability of PLA and the crystallinity of PLA increased with content of PBA (<15 wt.%). With the increase of PBA, the tensile strength and modulus of the blend decreased slightly while the elongation at break and toughness were dramatically increased. With the addition of PBA, the failure mode changes from brittle fracture of neat PLA to ductile fracture of the blend. Rheological results revealed the complex viscosity and melt elasticity of the blends decreased with increasing content of PBA and phase segregation occurred at loading above 11 wt.% PBA. UV–vis light transmittance showed that PLA/PBA blends with a high transparency, and the transmittance decreased with the amount of PBA.
研究领域:
材料科学
·
高分子科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）