高性能芳纶绝缘拉杆用树脂配方及性能研究

本文研究了双酚A、双酚F环氧树脂配方体系基础性能,对比分析了两种树脂配方浇注体的力学性能、电气性能和耐热性能,从试验数据得出双酚F配方体系改善了树脂配方耐热性能,却没有降低树脂工艺性能;并使用显微镜和SEM电镜观察绝缘拉杆复合材料结构,并其进行了各种性能测试。     

特种脂环族环氧树脂研制成功

华东理工大学研制出特种脂环族6269环氧树脂,该树脂的环氧值大于0．85,可作为活性稀释剂用于湿法缠绕、浇注、罐装等成型工艺制备耐热环氧复合材料。     

橡胶型导电涂料的研制

分析了环氧浇注用导电涂料的技术指标及其在铝合金嵌件中的作用,研制出了以氯丁橡胶为基料的导电涂料。结果表明,该涂料完全满足环氧浇注使用条件。     

新型无溶剂耐久液舱涂料的研制

采用低相对分子质量的酚醛环氧树脂，辅以自制增韧树脂、改性胺固化剂等，研制出了一种无溶剂酚醛环氧涂料。经性能检测及试验对比，该涂料耐热介质性能优异，具有超长的防腐寿命，解决了目前国内液舱涂料防腐寿命短（ 10 a左右）、维修频繁、耐热介质性能差等问题。可用作大型船舶污油水舱、灰水收集舱、残油收集舱、压载舱等液舱内壁的长效期防护涂料。     

填料对聚氨酯性能的影响

以4种填料合成了室温固化的聚酯型聚氨酯浇注胶,研究了填料的种类、用量以及复配形式对聚氨酯耐热形变性能、机械性能、耐水性能和热降解性能的影响。确定了最佳填料的配比,改善了聚氨酯的耐热形变性能。并进而发现填料的加入降低了聚氨酯的拉伸强度和耐水性能,但对热降解性能影响不大。     

风电叶片树脂用改性固化剂研究

研究了端环氧基硅烷改性的异佛尔酮二胺固化剂及其对双酚A型环氧树脂的固化性能测试了浇注体的力学性能及耐热性能,并用红外光谱分析了该固化剂在改性过程中的反应情况结果表明,用改性固化剂制备的树脂固化物具有良好的力学及耐热性能,可以满足风力发电叶片的需求.     

亨斯曼推出满足高热标准的环氧浇注体系

亨斯曼开发的AralditeXB2252／AradurXB2253冷固化环氧浇注体系可满足电容、滤波器及变压器制造的高热标准。由于该产品的室温下的低黏度和优异的流动性使得其易于采用浇注或真空浇注技术加工。取决于应用温度，其凝胶时间在30～100min变化，室温固化时间大约24h。该浇注体系还可用于热固化应用，已开发出满足F级要求产品。该产品具有优异的热性能包括良好的耐热循环，耐热和高导热性，还具有良好的耐热冲击性和阻燃性（UL94V一0）。     

浇注泥浆和模型——比较实心浇注和空心浇注的异同

浇注成型是陶瓷工业的一种重要成型方法,浇注成型的成败关键在于泥浆性能。泥浆的性能受胶粒的浓度、形状、大小和电解质等因素的影响(泥浆可看成胶体悬浮液)。卫生瓷和化学瓷以浇注成型为主要生产手段,日用瓷的异型产品也用浇注方法成型。浇注成型分空心浇注和实心浇注两类。日用瓷工厂中,壶类产品采用空心浇注,坯件较薄,鱼盘类产品采用实心浇注,坯件较厚,由于成型方法和坯件厚薄的不同,两者对泥浆和模型的要求也不同。下面谈谈浇注泥浆的胶粒浓度、形状、大小和电解质对泥浆性能的影响,着重分析日用瓷工厂中空心浇注泥浆和实心浇注泥浆的异同以及它们对石膏模型要求的差异。     

低粘度中温固化环氧树脂体系的基本性能

为满足环氧树脂在RTM、浇注、灌注等工艺中对低粘度的要求,通过对普通双酚A型环氧树脂进行改性,制备出一种低粘度的环氧树脂体系,并对其粘度、力学性能、耐热性能等进行了表征。结果表明,该体系在常温具有较长的适用期,中温固化后力学性能、耐热性能良好。     

干法棉型腈纶油剂的研制

根据干法棉型腈纶纺丝、纺纱工艺对油剂性能的要求,进行了油剂单体组分的筛选,并研究了干法棉型腈纶油剂的润湿、耐热、摩擦、抱合、抗静电等特性。所研制出的干法棉型腈纶油剂与国外同类产品比较,使用性能好于国外进口油剂。     

Non-isothermal Crystallization Kinetics of Poly (Ethylene Terephthalate)/Grafted Carbon Black Composite

Summary The grafted carbon black (GCB) was prepared by in-situ grafting low molecular weight compound on the surface of carbon black (CB) using a new technique. Poly(ethylene terephthalate)/grafted carbon black (PET/GCB) and poly(ethylene terephthalate)/ carbon black (PET/CB) composites were prepared by melt blending. The non-isothermal crystallization process of virgin Poly(ethylene terephthalate)(PET), PET/CB, and PET/GCB composites were investigated by differential scanning calorimetry (DSC), and the non-isothermal crystallization kinetics was analyzed using different approaches, i.e. modified Avrami equation, Ozawa equation and the method developed by Liu. The effective energy barrier ΔE of virgin PET, PET/CB, and PET/GCB composites were calculated using the differential iso-conversional method. All of the results showed that GCB and CB acted as nucleating agents and increased the crystallization rate of PET. Compared with CB, GCB was a more effective nucleator for PET.     

NR原位改性炭黑对NR胶料性能的影响

分别采用高温转矩流变仪和常温两辊开炼机制备NR原位改性炭黑(GCB)和NR/炭黑共混物(KCB),并制备GCB/NR和KCB/NR硫化胶,对其性能进行研究.结果表明,与KCB相比,GCB的耐热性能提高,结合橡胶质量分数增大;当炭黑用量相同时,与KCB/NR硫化胶相比,GCB/NR硫化胶的交联密度、定伸应力、压缩永久变形和储能模量较大,拉伸强度和回弹值较小;当炭黑用量小于60份时,GCB/NR硫化胶耐疲劳性能优于KCB/NR硫化胶.     

Effect of Grafted Carbon Black on Properties of Vulcanized Natural Rubber

Summary To modify carbon black (CB) surface, in situ grafting of natural rubber (NR) onto the CB surface by solid-state method was used to get grafted carbon black (GCB). The vulcanization characters of NR compounds employed CB and GCB were investigated. Crosslinking density of vulcanized NR was measured by equilibrium swelling method. As a result, it was found that GCB could improve both cure rate and crosslinking density. Moreover, the mechanical properties of vulcanized NR filled with GCB were enhanced to a large extent compared with vulcanized NR filled with CB. No Payne Effect was observed in GCB filled NR compounds during dynamic properties testing, indicating that there was no filler network and GCB was dispersed uniformly in NR matrix, which was proved by SEM micrographs. Based on above results, it was considered that the grafting modification weakened filler-filler interaction and enhanced filler-polymer interaction.     

Effect of modified carbon black on the filler–elastomer interaction and dynamic mechanical properties of SBR vulcanizates

A new modified carbon black (GCB) was prepared by adding special RFL latex into N220. Dynamic properties were obtained over a wide range of temperatures and strains on vulcanizates filled with GCB and unmodified carbon black, respectively. The results show that the GCB can effectively decrease the tan δ value at 60 and 90°C of SBR vulcanizates compared with that of the common unmodified carbon blacks, which responds to the fact that GCB is beneficial to lower rolling resistance and heat generation of the vulcanizates in comparison to that of the unmodified carbon black. Among the factors responsible for this, filler networking and filler–elastomer interaction play a dominant role. The effects of filler loading on mechanical properties of vulcanizates were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3707–3712, 2006     

Proteomic Landscape of Extracellular Vesicles for Diffuse Large B-Cell Lymphoma Subtyping

The role of extracellular vesicles (EVs) proteome in diffuse large B-cell lymphoma (DLBCL) pathology, subclassification, and patient screening is unexplored. We analyzed by state-of-the-art mass spectrometry the whole cell and secreted extracellular vesicles (EVs) proteomes of different molecular subtypes of DLBCL, germinal center B cell (GCB subtype), and activated B cell (ABC subtype). After quality control assessment, we compared whole-cell and secreted EVs proteomes of the two cell-of-origin (COO) categories, GCB and ABC subtypes, resulting in 288/1115 significantly differential expressed proteins from the whole-cell proteome and 228/608 proteins from EVs (adjust p-value < 0.05/p-value < 0.05). In our preclinical model system, we demonstrated that the EV proteome and the whole-cell proteome possess the capacity to separate cell lines into ABC and GCB subtypes. KEGG functional analysis and GO enrichment analysis for cellular component, molecular function, and biological process of differential expressed proteins (DEP) between ABC and GCB EVs showed a significant enrichment of pathways involved in immune response function. Other enriched functional categories for DEPs constitute cellular signaling and intracellular trafficking such as B-cell receptor (BCR), Fc_gamma R-mediated phagocytosis, ErbB signaling, and endocytosis. Our results suggest EVs can be explored as a tool for patient diagnosis, follow-up, and disease monitoring. Finally, this study proposes novel drug targets based on highly expressed proteins, for which antitumor drugs are available suggesting potential combinatorial therapies for aggressive forms of DLBCL. Data are available via ProteomeXchange with identifier PXD028267.     

A novel wound dressing composed of nonwoven fabric coated with chitosan and herbal extract membrane for wound healing

This study presents a novel design of an easily stripped bilayer composite that consists of an upper layer of soybean protein nonwoven fabric coated with a lower layer, genipin‐crosslinked chitosan and Bletilla striata herbal extract (GCB) film as a wound dressing material (GCB/NWF). Preliminary tests investigated the in vitro characteristics of the genipin‐crosslinked chitosan (GC) film. Experimental results showed that the dark bluish color of the GC film may have resulted from the reaction of genipin with the amino acid group in the chitosan solution. Additionally, adding more wt% genipin caused the bluish color of the GC films to be darker. This new wound dressing material also exhibited good mechanical properties. Genipin and chitosan were released from the soaked GC film. Cytotoxic test revealed that 20 ppm of the genipin in the culture medium could be criteria, over which cytotoxicity to L929 fibroblasts could be produced. However, the chitosan and B. striata herbal extract not only were not toxic but also promoted the viability and growth of L929 fibroblasts. Additionally, the GCB film more effectively supported cell attachment and growth. The in vivo histological assessment results revealed that epithelialization and reconstruction of the wound were achieved by covering the wound with the GCB/NWF wound dressing material, and it would be easily stripped from the wound surface without damaging newly regenerated tissue. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Production of a very low saturate oil based on the specificity of Geotrichum candidum lipase

Lipase B (GCB) produced by the fungus Geotrichum candidum CMICC 335426 is known for its high specificity towards cis-Δ9 unsaturated fatty acids. The wild-type lipase (not genetically modified) as well as the lipase obtained by heterologous expression of the corresponding gene in Pichia pastoris (genetically modified) were studied in a process aiming to produce an oil containing very little saturated fatty acids (SAFA). The approach described in this paper is based on the selective hydrolysis of sunflower oil (12% SAFA) using the G. candidum type B (GCB) lipases. Depending on the lipase input, up to 60% w/w degree of hydrolysis was obtained within 6–8 h. Because of the high specificity of the GCB lipases (specificity factor ∼30), the level of unsaturates in the free fatty acid fraction was >99% w/w. In contrast with literature data, no loss of specificity was observed, even at the highest degree of hydrolysis obtained. Though both GCB lipases are stable at 30°C, the rate of hydrolysis decreased considerably during the process. Product inhibition as well as time-dependent deactivation (half-life ≈2 h) were shown to be involved. After separation of the oil phase, the unsaturated free fatty acids were recovered from the mixture by evaporation and reconverted to triglycerides by enzymatic esterification with glycerol. Because the GCB lipases have a very low efficiency for esterification, this reaction was carried out with immobilized Rhizomucor miehei lipase. Under continuous removal of the water generated during the process, >95% triglycerides were obtained in less than 24 h. Standard deodorization resulted in an odorless, colorless, and tasteless oil with less than 1% SAFA.     

Use of ground clay brick as a pozzolanic material to reduce the alkali-silica reaction

The objective of this experimental study was to use ground clay brick (GCB) as a pozzolanic material to minimize the alkali-silica reaction expansion. Two different types of clay bricks were finely ground and their activity indices were determined. ASTM accelerated mortar bar tests were performed to investigate the effect of GCB when used to replace cement mass. The microstructure of the mortar was investigated using scanning electron microscopy (SEM). The results showed that the GCBs meet the strength activity requirements of ASTM. In addition, the GCBs were found to be effective in suppressing the alkali-silica reaction expansion. The expansion decreased as the amount of GCBs in the mortar increased.     

液相色谱-串联质谱法测定烤烟中甲基嘧啶磷的残留量

建立了液相色谱-串联质谱(HPLC-MS/MS)测定烤烟中甲基嘧啶磷的残留分析方法.试样采用乙腈提取,经GCB和C18净化剂净化后,用HPLC-MS/MS对甲基嘧啶磷进行定量分析.实验结果表明,甲基嘧啶磷在添加水平为0.03～3 mg/kg条件下的回收率为86.9％～92.5％,相对标准偏差为4.2％～11.5％.方法...