NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 24
·20015-20023
·
IF 3.201
Shi-Xian Zhang,Xiao-Li Wu,Tong-Hui Hao,Guo-Hua Hu,Tao Jiang,Qun-Chao Zhang,Hui Zhao
Environmentally friendly waterborne polyesters (WPEs) were obtained by copolymerization of diethylene glycol (DEG), isophthalic acid (IPA) and 5-sulfoisophthalic acid monosodium salt (5-SSIPA). The effects of the 5-SSIPA content on the properties of the resultant copolymers, including dispersity, crystallinity, dynamic thermo-mechanical properties, thermal stability and surface properties, were investigated. The 5-SSIPA contents in the intended polymers were determined by the peak areas of proton nuclear magnetic resonance (1H-NMR) spectra. Transmission electron microscopy (TEM), electrophoretic light scattering (ELS) and dynamic light scattering (DLS) were used to characterize the dispersion and stability performance of waterborne polyester solutions. The crystallinity of the WPEs was determined using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). As the 5-SSIPA content increased, the glass-transition temperature (Tg) of the WPEs increased significantly according to dynamic mechanical analysis (DMA), the thermal stability of the WPEs was deteriorated according to thermogravimetric analysis (TGA), surface roughness did not change according to atomic force microscopy (AFM), and their solid surface tension was increased from 28.47 to 32.90 mJ m−2 based on static contact angle measurements. Water contact angle (WCA) measurements proved that WPE dispersions could be used for enhancing the hydrophilicity of the PET surface.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Zhenzeng Wu,John Tosin Aladejana,Shuqiong Liu,Xinhuai Gong,Xiaodong Alice Wang,Yongqun Xie
Unsaturated polyester resin (UPR) with good chemical resistance, excellent mechanical properties, and formaldehyde-free shows great potentials in the wood industry. In this study, the mechanical strength, thermostability, dynamic thermomechanical property, and interfacial bonding of bamboo particle boards (BPBs) made from UPR adhesives with toluene diisocyanate (TDI) as the coupling agent were explored. The results showed that covalent bonds were formed among TDI, bamboo particles, and UPR, which could significantly enhance the mechanical strength. The internal bonding strength, modulus of elasticity, and modulus of rupture of treated BPBs were 1.36, 3010, and 19.6 MPa with the increment of 1250, 514, and 833%, respectively, compared to the control samples. Also, the thickness swelling rate of the BPB was 4.6%, much lower than that of the control, with a decrease of 92%. The thermostability of the treated BPB was also improved. As a result, the BPB using UPR as the adhesive and TDI as the coupling agent shows better usability, higher efficiency, and excellent mechanical strength.
研究领域:
材料科学
·
林业工程
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2021
·
IF 4.282
Yang Pan,Bin Yang,Ning Jia,Yangnan Yu,Xiang Xu,Yingying Wang,Bin Wu,Jiasheng Qian,Ru Xia,Chenjun Wang,Aiqing Sun,You Shi
In this work, multi-layer hot pressing (MLHP) method was used to prepare the graphene nanoplatelets (GNPs) filled polymethyl methacrylate (PMMA) composites. Effect of GNP content on the viscoelastic behavior and thermomechanical properties of composites was studied via rheometer, scanning electron microscope (SEM), infrared thermal imaging (ITI) and dynamic mechanical thermal analysis (DMTA), etc. According to dynamical rheological testing, thermorheological complexity was clearly displayed at elevated GNP content, based upon flow activation energy ( E a ) and time-temperature superposition (TTS) principle. The infrared thermal imaging (ITI) indicated that a filler conductive network was gradually formed with increasing filler content. The average heating rate of the samples increased from 0.74 to 0.92 °C/s. The Agari model was found to fairly interpret the variation of thermal conductivity as a function of GNP loading, which agreed well with SEM observation and indicative of the formation of a GNP network structure. Dynamic thermomechanical properties of the composites were heavily influenced by the temperature distributions within the samples. The addition of GNP increased the glass transition temperature of PMMA from 116.7 to 125.9 °C, which favored enhanced thermophysical properties of PMMA. The prepared composites in this work showed wonderful mechanical properties even at relatively high temperatures (e.g., having storage modulus of 1.3–1.9 GPa and yielding strength more than 58.0 MPa at 50 °C). The current work is practically significant for further expanding the application range of PMMA/GNP nanocomposites.
研究领域:
材料科学
·
复合材料
·
热力学
✓ 已验证
DOI
高影响因子
POLYMER COMPOSITES
·
2021
·Vol. 43
·期 1
·454-466
·
IF 3.171
Bo Song,Zhide Liu,Lei Chen,Lichun Ma,Yudong Huang
Poor interfacial properties are always one of the bottleneck problems limiting the development of the PBO fiber/epoxy composites. To solve this, we demonstrated a mussel-inspired molecular regulation strategy of interphase structure using the layer-by-layer construction of rigid (PDA) and flexible (PEI) molecules without fiber structure damage. The precise control on the molecular scale can maximally increase the roughness and polar functional group on the fiber surface, thus enhance the chemical bonding and the mechanical interlocking of the interfacial adhesion. In comparison with the untreated fiber, the IFSS and ILSS value of fiber with (PDA/PEI)n have an increment of 86.85% and 80.08%, respectively. Besides, the overall mechanical performance, such as impact strength and dynamic thermal-mechanical behavior, was also improved significantly, owing to the improved physical-mechanical attributes of the interphase. In brief, our study presents a non-destructive interface regulation of PBO fiber composite to enhance its interfacial adhesion and mechanical performance and optimize its structure/function integrated design.
研究领域:
材料科学
·
复合材料
·
表面化学
·
机械工程
✓ 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）