The preparation and characterization of urushiol powders (YPUOH) based on urushiol

Urushiol and lacquer sap from lacquer tree exhibit good antimicrobial and antioxidant properties. However, they are limited to commercial application due to their high volatility, low drying rate and allergic reaction. To overcome these limitations, solid-type urushiols (YPUOH), which is one of the essential factors for convenient handling in various industrial fields such as functional additives for paints, coating and composite films, were successfully prepared with urushiol and TPM. The reaction mechanism between urushiol and silane coupling agent has been evaluated based on Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). As-prepared YPUOH powders exhibited excellent antibacterial activity against E. coli and S. aureus, good antioxidant activity, and high thermal stability.     

基于天然高分子的可再生光刻材料的研究进展

与传统基于石油原料的光刻材料相比,基于天然高分子的可再生光刻材料不仅保留了高分辨率的光刻性能,还具有绿色可再生和无毒显影等优点.重点综述了天然高分子光刻材料中的蛋白类光刻材料和多糖类光刻材料,总结了各种天然高分子光刻材料的优缺点.通过对不同材料光刻机理的深入研究,总结出蛋白质光刻材料的光刻机理主要依靠辐射改变蛋白结构,使其溶解度在显影液中发生改变实现光刻;而天然多糖类光刻材料则主要依赖引入光响应基团实现光刻.最后对基于天然高分子的可再生光刻材料的现存问题进行了分析并对发展前景作出了展望.     

高导电镀银粒子/硅橡胶复合材料的制备研究

以自制玻璃微珠/银复合粒子作为导电填料、硅橡胶作为基胶,制备出具有高导电性能的硅橡胶复合材料,研究了导电复合粒子的添加量对橡胶复合材料物理性能和导电性能的影响。结果表明:自制玻璃微珠/银复合粒子的体积电阻率为3.14×10-4Ω.cm,导电性能优良;随着复合粒子添加量的增加,硅橡胶复合材料的导电性能和邵尔A硬度增加,但其它力学性能却呈下降趋势。当复合粒子的添加量为300phr时,硅橡胶复合材料的体积电阻率达到0.009Ω.cm,表现出优良的导电性能。     

Fabrication and distribution characteristics of polyurethane/single-walled carbon nanotube composite with anisotropic structure

A polyurethane/single-walled carbon nanotube (SWCNT) composite with anisotropic structure is synthesized by two-step process. The effects of external force during the curing process of the composite as well as the tensile stress on the distribution of the SWCNTs in the matrix have been examined by using field-emission scanning electron microscope. The microstructure analysis results indicate that the different distributions of the SWCNTs in the matrix have appeared along two orthogonal directions for the composite samples.     

Micelle and bilayer formation of amphiphilic janus particles in a slit-pore

We employ molecular dynamics simulations to investigate the self-assembly of amphiphilic Janus particles in a slit-pore consisting of two plane-parallel, soft walls. The Janus particles are modeled as soft spheres with an embedded unit vector pointing from the hydrophobic to the hydrophilic hemisphere. The structure formation is analyzed via cluster size distributions, density and polarization profiles, and in-plane correlation functions. At low temperatures and densities, the dominating structures are spherical micelles, whereas at higher densities we also observe wall-induced bilayer formation. Finally, we compare the MD results with those from a previous density functional study.     

Fabrication and mechanical properties of metal matrix composite with homogeneously dispersed ceramic particles

Titanium carbide (TiC) particles were coated with nickel (Ni) to increase their compatibility with a metal matrix, leading to an improvement in the dispersibility of TiC particles in the molten matrix. TiC particles were dispersed into a basic aqueous solution of pH 12, and then nickel nitrate (Ni(NO₃)₂), as a Ni precursor, was added to the TiC suspension. The interaction between the TiC particles and the Ni precursor is driven by the attractive force between the Ni cations and the TiC particles with negative charge. An inoculant (ferrosilicon), which has been used in the foundry industry to improve crystal growth of graphite, was used as a core particle. The Ni-treated TiC particles were coated onto the surface of the inoculant using an inorganic binder converted into its glass phase by sol–gel reactions. The reinforcement particles prepared through the dual-coating process were then injected into the molten matrix based on iron at 1500 °C. The crystal phase of the graphite is more finely and shortly grown in the reinforced metal matrix than in that without the reinforcement particles. This means that the reinforcement particles are homogeneously and uniformly dispersed into the matrix without any aggregation of particles, implying that the mechanical properties of the reinforced matrix would be greater than those of a non-reinforced matrix. Consequently, metal matrix composites with reasonable properties can be fabricated successfully using the reinforcement particles prepared by the dual-coating process.     

基于天然高分子的可再生光刻材料及其光刻机理的研究进展

基于天然高分子的新型光刻材料与石油原料的传统光刻材料相比,不仅保留了高分辨率的光刻性能,还具有绿色可再生和无毒显影等优点。本文综述了天然高分子光刻材料中的蛋白类光刻材料和多糖类光刻材料,系统的总结了各种天然高分子光刻材料的优缺点。通过对不同材料光刻机理的深入研究,得出蛋白质光刻材料的光刻机理主要依靠辐射改变蛋白结构,使其溶解度在显影液中发生改变实现光刻;而天然多糖类光刻材料则主要依赖引入光响应基团实现光刻。最后本文对基于天然高分子的可再生光刻材料的现存问题进行了分析并对发展前景做出了展望。     

Hybrid composite based on poly(vinyl alcohol) and fillers from renewable resources

Hybrid composite laminates consisting of polyvinyl alcohol (PVA) as continuous phase (33% by weight) and lignocellulosic fillers, derived from sugarcane bagasse, apple and orange waste (22% by weight) were molded in a carver press in the presence of water and glycerol such as platicizers agents. Corn starch was introduced as a biodegradation promoter and gluing component of the natural filler and synthetic polymeric matrix in the composite (22% by weight). The prepared laminates were characterized for their mechanical properties and degradative behavior in simulated soil burial experiments. The fibers type and content in composite impacted mechanical properties. Materials based on PVA and starch with apple wastes and sugarcane bagasse fillers were much harder (Young's Modulus respectively, 57, 171 MPa) than materials prepared with orange wastes (17 Mpa). Respirometric test revealed that soil microbes preferentially used natural polymers and low molecular weight additive as a carbon source compared to biodegradable synthetic polymer. The presence of PVA in formulations had no negative effect on the degradation of lignocellulosic fibers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Structured latex particles based on natural rubber for high-impact polymer blends

Natural latex (NR) particles, modified with a hard shell of poly(methyl methacrylate) (PMMA) and with a substructure of PMMA (type "NR-M") or polystyrene (type "NR-SM"), were tested as compatibilizers in blends of polycarbonate (of bisphenol A, PC) and PMMA or PS. During melt blending, the modified NR particles were torn apart, from an original size of >0.5 μm down to ≅0.1 μm in diameter. Two different types of particle distribution were observed in the blends: in PC/PMMA/NR-M blends, the NR-M particles were dispersed in the PMMA phase, whereas, in PC/PS/NR-SM blends, the NR-SM particles formed interface layers between PC and PS phase domains. The latter blend morphology, distinguished by continuous rubbery interface layers of NR-SM, turned out to be mechanically excellent in injection-moulded parts. The poor impact strength of PC/PS was raised by an order of magnitude. The effect depends on the orientation in the injection-moulded test bars.     

Thermoresponsive hydrogels based on renewable resources

This work aims to synthesize novel thermoresponsive hydrogels from renewable resources, bacterial cellulose (BC), and castor oil (CO), and to investigate the effect of CO on physical and thermal behaviors of BC/Poly(N-isopropylacrylamide) (PNIPAM) hydrogels. The structural properties of the hydrogels are analyzed by Fourier-transform infrared (FTIR) spectroscopy. Differential scanning calorimeter (DSC) technique and thermogravimetric analysis (TGA) are also performed to examine the thermal properties of the hydrogels. The morphological differences of the hydrogels are analyzed by scanning electron microscope (SEM). The thermoresponsive performances of the hydrogels are examined by swelling and deswelling behaviors. The hydrogel with CO is found to be more sensitive to temperature changes than the one without CO. Deswelling study demonstrates 91 and 25% of water loss for hydrogels with and without CO, respectively. The present study shows a novel approach to synthesize thermoresponsive hydrogels with renewable resources for biomedical applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48861.     

Fabrication of a zirconia/calcium silicate composite scaffold based on digital light processing

Zirconia (ZrO₂) and calcium silicate (CS) are widely used in bone repair. Zirconia has excellent mechanical properties, while calcium silicate has exceptional biological activity. A porous ZrO₂/CS composite ceramic scaffold was formed by digital light processing (DLP) technology in this study. The microstructure analysis demonstrated that CS was embedded between ZrO₂ particles. Mechanical tests showed that interconnected CS particles could improve mechanical properties, while discrete CS particles led to a decrease in that. Cell experiments showed that adding CS to ZrO₂ had a positive effect on cell proliferation and differentiation. In vitro degradation test showed that the weight loss of scaffolds in four weeks increased form ?0.63%–1.42% with the increase of CS content. Moreover, the degradation of scaffold promoted the deposition of apatite, which was beneficial to the integration of the scaffold with living bone. In conclusion, the ZrO₂/CS composite scaffold had better biocompatibility compared with the ZrO₂ scaffold, which showed a potential solution for 3D printing bone repair scaffolds.     

Fabrication and characterization of eggshell powder particles fused wheat protein isolate green composite for packaging applications

Ample biodegradable eggshell powder (ESP)/wheat protein isolate (WPI) composite films were made by solution casting method of altering the WPI solution and fused with ESP particles in the percentage of 5, 10, 20, 30, and 40% (w/w) and asses the properties, i.e., physical, mechanical, and thermal as a function of ESP concentration. Determine the unification of ESP particles into the WPI matrix by X‐ray diffraction, fluorescence spectra, and SEM analysis. The data clearly showed the successful incorporation of ESP particles and good compatibility with the WPI and also mechanical properties and thermal stability of composite film increasing with the increasing ratio of ESP. Microstructural evaluation confirmed the aggregation and distribution of ESP particles within the WPI matrix and validated the results of functional properties of the WPI/ESP film. The results confirmed that the composite films have potential applications in the field of food and medicinal packaging especially for photosensitive medicines in a very simple and cheap way. POLYM. COMPOS., 37:3280–3287, 2016. © 2015 Society of Plastics Engineers     

Composite natural rubber based latex particles: a novel approach

The oil resistance of natural rubber (NR) film could be effectively improved by using the heterocoagulation of large NR particle with small polychloroprene (CR) particles. In the preparation of NR/CR composite particle with a core-shell structure, a nonionic surfactant whose molecule bears poly(ethylene oxide) (PEO) was adsorbed on CR particles and allowed to form complexes between PEO and indigenous surfactant (protein-lipid) on the NR particle surface. Composite latex particle obtained was characterised by particle size, zeta potential and glass transition temperature measurements and the data indicated the presence of CR on the outer layer of composite particle. Better oil resistance of film casted from heterocoagulated latex when compared to that of NR film confirmed the NR/CR core-shell structure. The epoxidised natural rubber (ENR), crosslinked ENR and/or skim latex particles were investigated in order to replace the use of CR in the heterocoagulation process.     

Ni-P基纳米化学复合镀研究现状

阐述了Ni-P基纳米化学复合镀层沉积机理、结构、性能特点及影响因素。提出了目前纳米化学复合镀存在的主要问题，如镀液的稳定性、纳米粒子的分散性。综述了纳米化学复合镀的研究现状，并对今后的研究提出了建议。     

Fabrication of polyimide composite films based on carbon black for high‐temperature resistance

A novel high‐performance material, carbon black (CB) polyimide (PI), was obtained by the chemical synthesis of CB (carbon black N326) with PI. Following its synthesis, several analyses were carried out to investigate the thermal and mechanical properties of the newly synthesized CB‐PI. The thermal decomposition temperature of CB‐PI compared to PI increased by 76°C from 508 to 584°C. The glass transition temperature of CB‐PI as evaluated by differential scanning calorimetry increased by 204°C from 379 to 583°C compared to that of PI. Moreover, the mechanical strength of CB‐PI increased by 16% compared to that of PI. In addition, the analyses confirm that CB and PI in the synthesized CB‐PI were chemically crosslinked, which was shown to be responsible for the superior thermal and mechanical properties of the CB‐PI. POLYM. COMPOS., 35:2214–2220, 2014. © 2014 Society of Plastics Engineers     

生物质材料木材胶粘剂的研究进展

大豆蛋白作为一种廉价、易得、资源丰富、环境友好的生物质材料受到了广泛的关注,为了解决豆蛋白胶自身易水解、易受微生物侵蚀的缺陷,化学改性豆蛋白被广泛采用,以贻贝胶为模板对豆蛋白、木素等生物质材料进行化学改性用于制备木材胶粘剂也是研究的热点,本文对这2方面的研究进展做了简要的回顾。     

核壳复合粒子的制备

以硅烷偶联剂改性的纳米二氧化钛(SB570TiO为核材料,苯乙烯(St和二乙烯苯(DVB共聚物为壳材料,通过分散聚合法制备核壳复合粒子。通过用透射电子显微镜对粒子形态的观察,研究了稳定剂用量、引发剂用量、单体用量以及反应介质对核壳复合粒子制备的影响。结果表明,在mSB570TiO为1.47 gmSt为2.00 gmDVB为2.00 gm偶氮二异丁腈(AIBN为0.20 gm聚乙烯基吡咯烷酮K30PVP为2.00 g反应介质为乙醇时,能得到近球形的核壳复合粒子。     

莫来石—高硅氧玻璃复相材料的研制

研究了莫来石-高硅氧玻璃复相材料的相组成、显微结构、性能及应用。从相图出发，探讨了该复相材料的制备工艺和几种不同添加剂对制备该复相材料的影响。结果表明，含K2O化合物或矿物为较理想的助熔剂，以高钾矿物为添加剂，以高岭土为原料，制备了不含方石英和刚玉、莫来石含量在55％～60％的莫来石-高硅氧玻璃复相材料，该复相材料的体积密度为2．56g·cm－3，耐火库为1750～1770℃，室温至1300℃的热膨胀系数为4．2×10－6K－1。     

纳米晶金刚石织构粒子增强银基电接触复合镀层的研究

采用具有纳米晶织构的金刚石微粒强化银基电接触复合镀层。研究了金刚石微粒的粒度和浓度对复合镀层外观，微观形貌、硬度、耐磨性、接触电阻及电磨损率的影响。结果表明，金刚石粒子的加入能有效提高银镀层的耐磨性和电接触使用寿命。与压机合成的单晶金刚石微粒相比，纳米晶金刚石粒子与银基体的结合力更强。