麦秆液化物环氧树脂的制备与表征

以苯酚为溶剂,浓硫酸为催化剂液化麦秆得到麦秆液化产物,并以其为原料与环氧氯丙烷反应制备出以麦秆液化物为基材的环氧树脂。考察了液比(苯酚与麦秆质量比)、反应温度和反应时间对液化反应的影响。采用凝胶渗透色谱(GPC)对比分析了麦秆液化物及其环氧树脂的相对分子量分布。以聚酰胺为固化剂进行固化并进行力学测试。结果表明:在液比为4∶1,反应温度为150℃,反应那个时间为60min时,麦秆液化效果最佳,此时,麦秆液化物环氧树脂固化物的剪切强度可达4.1MPa。     

Reproducibility of w/c ratio determination from fluorescent impregnated thin sections

The ease and reproducibility of preparing fluorescent epoxy impregnated thin sections for w/c determination of concrete has been studied. Five sets of thin sections were prepared from 6 concrete mixes having different compositions and w/c ratios (0.35 to 0.80). The thin sections were prepared by different technicians and produced over a period of nearly a year. The quality of the thin sections was checked and the w/c ratio determined by seven petrographers using fluorescent light microscopy as a Round Robin test.The investigation showed that, within a reasonable time, different technicians were able to produce a comparable quality of fluorescent epoxy impregnated thin sections, even though the thin sections were produced from concrete at different ages and using different equipment and chemicals. The petrographers were able to distinguish between the green shades of the fluorescent dye epoxy impregnated cement paste, with sufficient accuracy. The result of the w/c Round Robin test gave standard deviations between 0.02 and 0.03 (average 0.026).     

Pyrolysis oil substituted epoxy resin: Improved ratio optimization and crosslinking efficiency

The objective of this study was to determine the compatibility of whole pyrolysis oil (PO) of pine as a substitute for the phenolic component of epoxy resins (ER). Pyrolysis oil‐based epoxy resin (POBER) was synthesized by modification of EPON828 ER with PO at various mixing ratios (1 : 3–1 : 8, PO:EPON828, w/w). Acetone extraction determined that a ratio of 1 : 7–1 : 8 resulted in a fully reacted thermoset, leaving neither PO nor EPON828 in a significantly unreacted state. Dynamic mechanical analysis (DMA) revealed that a ratio of 1 : 8 produced the highest storage modulus (E’); in addition, it was determined that this ratio provided a superior glass transition temperature (Tg) of 120°C and crosslinking density of 1891 mol/m³. FTIR spectra concluded that the reaction between the EPON828 and PO was complete at the 1 : 8 ratio, citing the removal of hydroxyl and epoxide peaks within the cured product. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42239.     

Modification of Acid Anhydride-cured Epoxy Resins By N-Phenyl- maleimide–Styrene Copolymers and N-Phenylmaleimide–Styrene– p-Hydroxystyrene Terpolymers

N-Phenylmaleimide–styrene copolymers (PMS) and reactive N-phenylmaleimide–styrene–p-hydroxystyrene (HSt) terpolymers (PMSH) containing p-hydroxyphenyl groups were used to improve the toughness of bisphenol A diglycidyl ether epoxy resin cured with methyl hexahydrophthalic anhydride. PMS and PMSH were effective modifiers for epoxies. The morphologies of the modified resins depended on modifier structure and content. The most effective modification for the cured resins was attained because of the co-continuous structure of the modified resins in both PMS and PMSH modification systems. When using 15wt% of PMS (M¯_w 125000), the fracture toughness, K_IC, for the modified resin increased by 230%, with retention of flexural modulus and glass transition temperature, but with a loss of flexural strength, compared with the values for the unmodified epoxy resin. When using PMSH as the reactive modifier, the efficiency decreased with increase in HSt content, because of the increasing extent of dispersion of the PMSH-rich continuous phases. In the modification with 10wt% PMSH (1·0mol% HSt unit, M¯_w 294000), the modified resin had balanced physical properties. © of SCI.     

PBT/PA610共混合金的制备及其力学性能的研究

选用环氧树脂(EP)、(苯乙烯/乙烯-丁烯/苯乙烯)三嵌段共聚物接枝马来酸酐(SEBS-g-MAH)和(乙烯/马来酸酐/甲基丙烯酸缩水甘油酯)三元共聚物(EMG)为增容剂,采用熔融挤出的方法制备了PBT/PA610/EP、PBT/PA610/EP/SEBS、PBT/PA610/EP/EMG3种合金,研究了这3种合金的力学性能。结果表明,当PBT/PA610/EP的质量比为70/30/3时,合金的冲击强度比不加EP时提高了37.3%,比纯PBT提高了91.2%;而且在PBT/PA610/EP的质量比为70/30/3时,随着SEBS-g-MAH和EMG含量的增加,合金的冲击强度也明显提高。     

Toughening of aromatic diamine-cured epoxy resins by modification with hybrid modifiers composed of N-phenylmaleimide–styrene copolymers and N-phenylmaleimide–styrene–p-hydroxystyrene terpolymers

Hybrid modifiers composed of N-phenylmaleimide–styrene copolymers (PMS), and N-phenylmaleimide–styrene–p-hydroxystyrene terpolymers (PMSH) containing pendent p-hydroxyphenyl groups as functionalities, were used to improve the toughness of bisphenol-A diglycidyl ether epoxy resin cured with p,p′-diaminodiphenyl sulphone. The hybrid modifiers were effective in toughening the epoxy resin. When using the modifier composed of 10 wt% PMS (M?_w 313000) and 2.5 wt% PMSH (2.5 mol% p-hydroxystyrene units, M?_w 316000), the fracture toughness (K_IC) for the modified resins increased 100% with no deterioration in the flexural properties and the glass transition temperature. The improvement in toughness of the epoxy resins was attained because of the co-continuous phase structure and the improvement in interfacial adhesion. The toughening mechanism is discussed in terms of the morphological characteristics of the modified epoxy resin systems.     

Synthesis and characterization of water‐soluble polymeric adhesion promoter for epoxy resin/copper joints

Nobel polymeric adhesion promoter soluble in water was synthesized to improve the adhesion strength of copper lead frame/epoxy molding compound (EMC) joints. N‐(4‐phenolyl)‐(benzotriazole‐5‐carboxylic)amide (PBCA) was synthesized by reacting benzotriazole‐5‐carboxylic acid (CBTA) with 4‐aminophenol. Poly[acrylic‐co‐4‐(5‐benzotriazole)amido phenyl acrylate] (PAB) was synthesized by reacting poly acryloyl chloride with PBCA. The adhesion strength of PAB‐treated copper lead frame/epoxy resin joints increased with the increase of PBCA content in PAB by forming more Cu‐triazole complex. The adhesion strength of PAB‐treated copper lead frame/epoxy resin joints having high PBCA content in PAB (more than 0.3 of mole ratio) is comparable to that of polybenzimidazole (PBI)‐treated copper lead frame/epoxy resin joints. However, the adhesion strength of PAB‐treated copper/epoxy resin joints decreased with the increase of PAB treatment time since Cu‐triazole complex particles were formed on PAB‐treated copper surface and acted as defects. The initial adhesion strength was maintained by suppressing the formation of Cu‐triazole complex particles using PAB having low PBCA contents (0.003 mole ratio of PBCA). The solubility of PAB in water was dependent on the mole ratio of carboxylic acid to PBCA in PAB. The increase of carboxylic acid content in PAB improved the solubility of PAB in water but decreased the adhesion strength with copper. PAB containing 0.03 mole ratio of PBCA was soluble in water. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2202–2210, 2002     

Enhanced mechanical,thermal and adhesion properties of polysilsesquioxane spheres reinforced epoxy nanocomposite adhesives

ABSTRACT

Epoxy-based systems serve as excellent adhesives to join a wide range of substrates such as metal, ceramics, plastics, etc. The mechanical properties of such systems can be improved considerably by the addition of filler to the epoxy matrix. Herein, polymethylsilsesquioxane (PMS) and poly(methyl/vinyl)silsesquioxane (PMVS) nanosphere were synthesised by hydrolytic condensation of oraganosilane as a precursor in aqueous phase. The epoxy nanocomposite adhesives were prepared by adding different weight percentages (1–4 wt%) of the PS nanospheres. Tensile and compressive strength of the adhesive formulations were studied using the universal testing machine (UTM) and it was observed that the mechanical properties of the composites showed an increasing trend on increasing the filler loading. Adhesive strength of the epoxy composites on mild steel substrate was studied by conducting the lap shear test and EPV-4 exhibited a 31% increase in adhesive strength on the mild steel compared to the neat epoxy. Surface morphology of the epoxy composites were visualised from the SEM images and the composites also showed enhanced thermal conductivity. Higher mechanical and adhesive strength indicates the potential of the prepared nanocomposites to be used as an effective formulation in adhesive-based systems.     

Potassium methyl siliconate‐treated pulp fibers and their effects on wood plastic composites: Water sorption and dimensional stability

Potassium methyl siliconate (PMS) was investigated as a new nano modifier of wood fiber and wood flour to improve the compatibility between the fiber/flour and the plastic matrix in fiber reinforced plastic composites. Before injection molding, bleached and brown pulp fibers and mixed species wood flour were pretreated in PMS solutions. The morphology of the treated and untreated fiber and flour, the compatibility of PMS‐treated fiber and flour with polyethylene (PE), and the water sorption and volumetric swell of PMS‐treated fiber/flour plastic composites in a long‐term soaking test were evaluated. Fiber and flour treated with PMS increased the compatibility between the fiber/flour and the PE matrix. The increased compatibility of PMS‐treated fiber and flour with the matrix contributed to the reduction of water sorption and, thus, increased dimensional stability. For all composites, water sorption and volumetric swell of fiber/four plastic composites decreased as the ratio of fiber to flour increased. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

生物炭/过一硫酸盐体系同时去除Cu2+和对硝基苯胺

目前,重金属离子和有机污染物共存的废水处理是一个世界性的重大问题,对环境保护具有重要的意义。本研究以农业废弃物向日葵秸秆为原料,制备了一种生物炭（BC）,用以活化过一硫酸盐（PMS）。BC/PMS体系实现了对水中重金属Cu²⁺和有机污染物对硝基苯胺（PNA）的同时去除。探究了pH、BC投加量和PMS浓度等反应条件对同时去除Cu²⁺和PNA的影响。研究表明,在BC=2.0g/L、PMS=1.0mmol/L、PNA=20.0mg/L、Cu²⁺=2.0mg/L和pH=3.0条件下,60min时Cu²⁺和PNA同时去除效率分别为90.00%和100.00%;Cu²⁺被BC/PMS体系吸附去除的同时也显著地促进了PNA的降解去除。自由基猝灭实验和电子顺磁共振光谱（EPR）实验表明,BC/PMS/Cu²⁺/PNA体系降解PNA为自由基反应和非自由基反应共存过程,且以非自由基反应为主导;自由基反应是基于Cu²⁺活化PMS产生SO{}_{\mathrm{4}}^{·-}和?OH,非自由基反应可归因于BC活化PMS产生活性物种¹O₂。     

Resistance of paper mill sludge/wood fiber/high‐density polyethylene composites to water immersion and thermotreatment

The disposal of paper mill sludge (PMS) is a difficult environmental problem. Thus, PMS has been used as a substitute for wood fiber (WF) to reinforce high‐density polyethylene (HDPE). In this study, we compared PMS–WF–HDPE composites with composites without PMS after water immersion and thermal treatment. Water immersion and thermal treatment were conducted at 25 and 70°C, respectively. The results show that the composites with PMS absorbed less water but lost more of their original flexural properties after immersion; thereby, their strength was compromised. These reduced mechanical properties could be partially restored after redrying. After the thermotreatment, the composites with added PMS lost their weight and flexural properties, whereas the composites without PMS gained flexural strength. The results show that the thermotreatment improved the impact strength of the composites when no more than one‐third of WF was replaced with PMS. Fourier transform infrared spectroscopy and energy‐dispersive X‐ray energy‐dispersive spectroscopy showed that the wood index of the PMS composite decreased more than the index of the non‐PMS composite, whereas the carbonyl index increased more. However, the PMS composite showed a lower increase in the total oxygen/carbon weight ratio. This study suggested that limited amounts of WF could be substituted with PMS to reinforce HDPE. However, WF–PMS–HDPE composites should not be used in hot, humid environments for long periods. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41655.     

电热双敏型形状记忆石墨烯/聚氨酯/环氧树脂复合材料的制备及其性能

以自制聚氨酯预聚体与环氧树脂复合形成互穿聚合物网络结构,采用共混方法添加自制高导电性石墨烯,制备了电热双敏型形状记忆复合材料,研究了其性能. 结果表明,以20%(w)聚氨酯/环氧树脂为基体所制1.0%(w)石墨烯/聚氨酯/环氧树脂复合材料的分散性良好,玻璃化转变温度稍低于纯环氧树脂,拉伸强度是纯环氧树脂的93%,导电性达3.58′10-4 S/m,固定率为95.5%,回复率为97.5%,循环5次后固定率不低于95%.     

LaCoO3钙钛矿活化过一硫酸盐降解萘普生

在催化活化过一硫酸盐(PMS)降解水中污染物的反应中,通过添加钴基钙钛矿提高反应效率。利用溶胶凝胶法制备了LaCoO₃钙钛矿,通过实验评估LaCoO₃/PMS体系对非甾体抗炎药萘普生（NAP）的降解效果。分析了LaCoO₃投加量、PMS投加量、反应初始pH、Cl^-浓度和腐殖酸（HA）对NAP去除率的影响以及该体系的矿化能力。结果表明NAP降解的反应速率随LaCoO₃和PMS投加量增加而增大;反应初始pH在5.0时NAP降解效果最好;溶液中存在Cl^-对降解有促进效果,且Cl^-浓度越大促进效果越明显;腐殖酸（HA）对反应有一定程度的抑制效果;LaCoO₃在重复利用5次时仍有较好的稳定性。此外,自由基淬灭实验结果表明在LaCoO₃/PMS体系中SO₄^·-为主要活性物质。     

Preparation and properties of cyanate ester modified by epoxy resin and phenolic resin

Stiff and brittle cyanate ester (CE) resin was modified by copolymerizing it with epoxy resin (ER) and phenolic resin (PR) to improve its toughness and flexibility. The cure process of the modified CE resin was characterized by gel time curves and differential scanning calorimetry curves. The Fourier transform infrared spectra of the modified CE resin showed its chemical structure during the curing process. The mechanical properties, thermal behavior, dielectric properties, and morphology of the modified CE resins were investigated. The results showed that an increase in epoxy and phenolic resins resulted in improved flexibility while maintaining thermal stability. When the mass ratio of CE/ER/PR was 70 : 15 : 15 (w/w), flexural strength and impact strength of the modified CE resin increased from 113.6 MPa and 5.2 kJ/m² to 134.5 MPa and 16.7 kJ/m², respectively. Little of the thermal stabilityand dielectric properties was sacrificed in the modification of the CE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3150–3156, 2007     

预处理法合成环氧化反式-1,4-聚异戊二烯及其结构与性能

采用预处理法对反式-1,4-聚异戊二烯(TPI)进行环氧化改性,合成了具有不同环氧度的环氧化TPI( ETPI),考察了预处理剂/水(体积比,下同)、投料比[过氧乙酸/TPI(摩尔比,下同)]对ETPI环氧度的影响,并对ETPI的结构及性能进行了表征.结果表明,预处理法合成的ETPI其环氧度显著提高,当预处理剂/水为7...     

Polyurethane-modified epoxy resin and their polymer particle filled epoxies

Hydroxyl-terminated polyurethane (HTPU) prepolymer and crystalline polymer particles were used to modify the toughness of diglycidyl ether of bisphenol-A (DGEBA) epoxy cured with diaminodiphenyl sulphone (DDS). For the crystalline polymers, poly(butylene terephthalate) (PBT) and poly(hexamethylene adipamide) (Nylon 6,6), with particle size under 401 m were employed. The PU-modified epoxies exhibit a significantly improved fracture toughness. The -relaxation of cured epoxy resin shows a more clear two-phase separation as the polyurethane content increases. Besides, the addition of crystalline polymer particles could further enhance the toughness of PU-modified epoxy at low particle content. Scanning electron microscopy (SEM) shows that PU-modified epoxy has a two-phase structure. The fracture properties of PBT particle filled epoxy are found to be better than those of Nylon 6,6 particle filled epoxy. Nevertheless, the toughening effect of these crystalline polymer particles is much less efficient than that of PU modification.     

Influence of fiber modification on interfacial adhesion and mechanical properties of pineapple leaf fiber‐epoxy composites

Three kinds of surface treatment, that is, the alkalization (5% w/v NaOH aqueous solution), the deposition of diglycidyl ether of bisphenol A (DGEBA) from toluene solution (1% w/v DGEBA), and the alkalization combined with the deposition of DGEBA (5% w/v NaOH/1% w/v DGEBA) were applied to modify interfacial bonding and to enhance mechanical properties of pineapple leaf fiber (PALF) reinforced epoxy composites. The fiber strength and strain were measured by single fiber test and the fiber strength variation was assessed using Weibull modulus. Furthermore, a fragmentation test was used to quantify the interfacial adhesion of PALF‐epoxy composite. It was verified that the interfacial shear strength of modified PALFs was substantially higher than that of untreated PALF by almost 2–2.7 times because of the greater interaction between the PALFs and epoxy resin matrix. The strongest interfacial adhesion was obtained from the fibers that had been received the alkalization combined with DGEBA deposition. Moreover, the flexural and impact properties of unidirectional PALF‐epoxy composites were greatly enhanced when reinforced with the modified PALFs due to an improvement in interfacial adhesion, particularly in the synergetic use of 5% NaOH and 5% NaOH/1% DGEBA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚环氧酯的合成及其对PC/ABS相容性的影响

以双酚A环氧树脂和己二酸合成了聚己二酸环氧酯,将环氧酯作为相容剂加入到PC/ABS中通过双螺杆挤出机并注射成型制备了合金,与马来酸酐接枝聚苯乙烯（SMA）相容剂增容的合金的力学性能及分散形态进行了对比。结果表明,聚环氧酯对PC相具有良好的相容性,而SMA对ABS相的相容性较好,二者复合使用可以显著改善合金的相容性;聚环氧酯能明显提高PC/ABS合金的拉伸强度和缺口冲击强度,但过量加入会降低合金的冲击强度;SEM结果表明少量的聚环氧酯即可以使ABS分散相分布均匀,与SMA并用可以使分散相尺寸减小,提高相容性。     

Improvement of bitumen performance with epoxy resin

This paper studies the modification of petroleum bitumen with epoxy resin. Different amounts of epoxy were doped into bitumen with 50/70 penetration grade and variations in viscosity as a function of temperature and additive concentration were determined. The effects of the epoxy additive were examined by rheometer, penetration, softening point, DSR (dynamic shear rheometer), DSC (differential scanning calorimeter), RTFOT (rolling thin film oven test), PAV (pressure aging vessel), BBR (bending beam rheometer) and surface tension tests. Adhesion and stability of bitumen aggregate mixtures prepared using original and modified bitumen were compared using Nicholson stripping and Marshall tests. The optimum dosage of the additive yielding the best rheological and performance properties was found to be 2% (w/w). Appreciable decrease in the formation of rutting, bleeding, stripping and cracking of modified bitumen may be obtained through epoxy addition.     

聚醚改性硅油乳化剂的合成及其在特种有机硅消泡剂中的应用

以端烯丙基聚醚F6、含氢硅油为原料,氯铂酸为催化剂,甲苯为溶剂,合成出聚醚改性硅油(PMS),并用红外光谱对其结构进行表征。正交实验优化合成条件为:原料中Si—H与CC的量之比为1∶1.2,催化剂用量为30×10-6,反应温度100℃,甲苯质量分数30%,该条件下反应3 h,含氢硅油中Si—H的转化率达98.7%。将其与白炭黑、甲基硅油等复配,制得粒径小、分布范围窄、球状颗粒的消泡剂。该乳液在65℃下贮存稳定,在高温、不同pH值(2～13)条件下不分层、不漂油,且能保持消泡速度快、抑泡活性强的特点。在PMS用量为起泡液质量的0.06%,鼓泡速度为3.0 L/min条件下,消泡剂可在5.5 s内使高度为500 mL的泡沫迅速破裂,抑泡时间长达1 510 s。