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1.
楚定一  丁剑平  熊康  方跃胜  刘运春 《橡胶工业》2023,70(11):0868-0875
研究过氧化物硫化剂BIBP反应副产物对氯化聚乙烯橡胶(CM)/三元乙丙橡胶(EPDM)电缆绝缘层硫化胶绝缘性能的影响,并引入新型助剂活化剂A替代部分BIBP,在不影响CM/EPDM胶料其他性能的同时提高硫化胶的体积电阻率。结果表明:基于本试验配方,当减少0.7份BIBP并加入0.45份活化剂A时,CM/EPDM胶料的硫化特性、硫化胶的物理性能没有下降;100 ℃×168 h老化后CM/EPDM硫化胶的拉断伸长率减小率增大,但符合国家和行业标准要求;CM/EPDM硫化胶浸水前的体积电阻率由1.3×1013 Ω·cm提高至5.0×1014 Ω·cm,浸水28 d后的体积电阻率由3.6×1010 Ω·cm提高至5.4×1012 Ω·cm,其绝缘性能大幅提高。进一步研究发现,BIBP在硫化过程中产生的副产物的量的变化是导致CM/EPDM胶料性能变化的主要原因,扫描电子显微镜观测到的浸水后硫化胶断面微观形貌也验证了这一结论。  相似文献   

2.
炭黑填充聚偏二氟乙烯导电性研究   总被引:5,自引:3,他引:5  
为获得具有较大电阻温度系数和良好热稳定性的导电塑料,研究了填充不同类型炭黑的聚偏二氟乙烯的导电性能。结果表明,填充高导电炭黑和高耐磨炭黑混合物的聚偏二氟乙烯电阻温度系数可达4.3×10~(-2)Ω·cm/℃,该导电塑料随聚偏二氟乙烯的结晶度提高,电阻率热稳定性提高。  相似文献   

3.
促进剂在导电胶中的作用研究   总被引:2,自引:1,他引:1  
以环氧树脂(EP)为基体树脂、2-乙基-4-甲基咪唑为固化剂、银包铜粉为导电填料、KH-550为硅烷偶联剂和DBGE为促进剂,制备了一种各向同性导电胶。探讨了促进剂用量对导电胶导电性能的影响,并采用红外光谱(FT-IR)、扫描电镜(SEM)及差示扫描量热(DSC)分析法等对导电胶的机理进行了研究。结果表明:随着促进剂用量的增加,导电胶的体积电阻率呈先降后升的趋势;当w(促进剂)=2%时,导电胶的导电性能最好(体积电阻率为1.9×10~(-3)Ω·cm);促进剂的加入能够部分去除导电粒子表面的有机润滑层,从而提高了导电胶的导电性能。  相似文献   

4.
磨碎碳纤维增强环氧树脂复合材料的性能研究   总被引:1,自引:0,他引:1  
牛牧童  吴伟端  陈名名 《塑料工业》2006,34(8):54-56,69
利用两种不同的磨碎碳纤维粉体(CFP)填充环氧树脂(EP),通过熔融共混制备了EP/CFP复合材料。研究了CFP含量、长度与复合材料导电性能、力学性能和热稳定性能的关系,并考察了材料断口形貌。研究表明:P-100型CFP填充的质量分数为25%时,EP/CFP材料的体积电阻率为1.34×106Ω·cm;拉伸强度、拉伸弹性模量、冲击强度和弯曲强度较EP分别提高了124%、186%、98.7%和66.7%,同时材料的热稳定性也略有提高。  相似文献   

5.
赵宜武  邹华  田明  张立群  李淑环 《橡胶工业》2015,62(12):709-712
研究镀镍石墨(NCG)用量对NCG/三元乙丙橡胶(EPDM)导电复合材料性能的影响,遴选出最佳硅烷偶联剂,研究其用量对复合材料导电稳定性的影响、,结果表明,随着NCG剧量的增大,复合材料的体积电阻率逐渐降低,当NCG用量超过240份时,复合材料的体积电阻牢降至10 Ω·cm以下、Al37足一种有效的硅烷偶联剂,当其用量为9份时,复合材料的各项性能较好。  相似文献   

6.
采用新的铝掺杂方法,降低了氧化锌晶须的本体电阻率;研究了铝掺杂对氧化锌晶须电阻率的影响。含20%掺量的氧化铝使氧化锌晶须的表面电阻率从107~108Ω降低到1·6×106Ω,体积电阻率从108~109Ω·cm降低到7·1×105Ω·cm;研究了铝掺杂氧化锌晶须对环氧树脂抗静电性能的影响,铝掺杂氧化锌晶须的添加量为8%,使涂层的表面电阻降低到7·2×1010Ω。  相似文献   

7.
以膨胀石墨所固有的导电性能和蓬松多孔的层状结构为基础,借鉴插层复合方法,通过浇铸尼龙6(MCPA6)与石墨片层之间的纳米复合,提高MCPA6的导电性能,达到抗静电的要求。通过导电性能测试及XRD、OM和SEM分析,研究了浇铸尼龙6/膨胀石墨抗静电复合材料的纳米结构及导电机理。结果表明:当膨胀石墨质量分数为1.0%时,体积电阻率已下降到1.99×10~8Ω·cm,实现了抗静电目标。  相似文献   

8.
概述了用双螺杆挤出机试制导电塑料母料的工艺过程,并就成型温度、进料速度、停留时间等因素,对导电塑料母料导电性的影响进行了讨论。用黄铜纤维复合的导电塑料母料的体积电阻率可达到20×10~(-3)Ω·cm。  相似文献   

9.
铜粉添加型导电胶的研制   总被引:1,自引:0,他引:1  
以环氧树脂E-51为导电胶基体树脂、二乙烯三胺为固化剂,采用硅烷偶联剂(KH-550)对铜粉进行改性处理,并以此作为导电填料,制备了热固化各向同性导电胶。通过正交实验探讨了固化剂、硅烷偶联剂、还原剂、稀释剂和导电填料等因素对导电胶固化性能、粘接性能和导电性能的影响,并对导电胶的制备参数进行优化,得到了制备导电胶的最佳方案。实验结果表明,所制备的热固化各向同性导电胶具有制备工艺简单、粘接强度高(剪切强度≥20 MPa)和导电性能好(体积电阻率为1.50×10-3Ω·cm)等特点;经室温1000h老化实验后,导电胶的体积电阻率和剪切强度变化率<20%。  相似文献   

10.
岑茵  许国志 《中国塑料》2007,21(9):49-52
研究了碳纤维(CF)不同的表面处理方法对PE—HD/EVA/CF复合材料导电性能的影响,包括硝酸液相氧化处理和硅烷偶联剂KH560、KH550包覆处理。结果表明,用偶联剂处理的复合体系,其体积电阻率随着CF的用量增加呈下降趋势。KH560包覆处理体系的最低体积电阻率为3.63×10^9Ω·cm,KH550处理体系为7.94×10^9Ω·cm。KH560的偶联处理效果总体较佳,导电渗阈值出现在5份,而且KH560最佳使用量为0.8份。硝酸液相氧化处理效果比偶联剂好,随着氧化时间的延长,复合体系的导电性能随之改善,最佳氧化时间为7h,其导电渗阈值在3.5份左右,体积电阻率从10^13Ω·cm下降到5.75×10^8Ω·cm。  相似文献   

11.
陆泉芳  俞洁  杨彩玲  李敏睿 《化工学报》2018,69(6):2664-2671
用辉光放电电解(GDE)技术对模拟染料废水阳离子桃红FG的降解过程进行了研究。通过发射光谱法测定了GDE产生的活性粒子,用紫外光谱和总有机碳(TOC)分析仪研究了不同放电时间下的脱色率和去除率,用电导率仪和酸度计测定了降解过程中溶液的电导率和pH的变化,同时用离子色谱对降解中间产物进行了分析。结合各种分析结果,探讨了GDE降解阳离子桃红FG的机理。结果表明,在最佳电压600 V时,溶液中产生HO·、O·、H·等高活性粒子;放电120 min时,200 ml 20 mg/L阳离子桃红FG的脱色率和TOC去除率分别可达99.0%和72.6%;降解液pH先减小后增大,电导率存在先增大后减小的趋势;离子色谱测试表明,降解过程中产生多种有机小分子酸。羟基自由基(HO·)对阳离子桃红FG的降解起关键作用,GDE降解阳离子桃红FG的机理为:HO·作用下助色基团键断裂,产生酚类等中间产物,然后继续被降解为醌和小分子有机酸,最终矿化为Cl-、NO3-、CO2和H2O。  相似文献   

12.
13.
Cannabidiol (CBD), a nonpsychoactive phytocannabinoid, has recently emerged as a potential cytotoxic agent in addition to its ameliorative activity in chemotherapy-associated side effects. In this work, the potential interactions of CBD with docetaxel (DOC), doxorubicin (DOX), paclitaxel (PTX), vinorelbine (VIN), and 7-ethyl-10-hydroxycamptothecin (SN−38) were explored in MCF7 breast adenocarcinoma cells using different synergy quantification models. The apoptotic profiles of MCF7 cells after the treatments were assessed via flow cytometry. The molecular mechanisms of CBD and the most promising combinations were investigated via label-free quantification proteomics. A strong synergy was observed across all synergy models at different molar ratios of CBD in combination with SN−38 and VIN. Intriguingly, synergy was observed for CBD with all chemotherapeutic drugs at a molar ratio of 636:1 in almost all synergy models. However, discording synergy trends warranted the validation of the selected combinations against different models. Enhanced apoptosis was observed for all synergistic CBD combinations compared to monotherapies or negative controls. A shotgun proteomics study highlighted 121 dysregulated proteins in CBD-treated MCF7 cells compared to the negative controls. We reported the inhibition of topoisomerase II β and α, cullin 1, V-type proton ATPase, and CDK-6 in CBD-treated MCF7 cells for the first time as additional cytotoxic mechanisms of CBD, alongside sabotaged energy production and reduced mitochondrial translation. We observed 91 significantly dysregulated proteins in MCF7 cells treated with the synergistic combination of CBD with SN−38 (CSN−38), compared to the monotherapies. Regulation of telomerase, cell cycle, topoisomerase I, EGFR1, protein metabolism, TP53 regulation of DNA repair, death receptor signalling, and RHO GTPase signalling pathways contributed to the proteome-wide synergistic molecular mechanisms of CSN−38. In conclusion, we identified significant synergistic interactions between CBD and the five important chemotherapeutic drugs and the key molecular pathways of CBD and its synergistic combination with SN−38 in MCF7 cells. Further in vivo and clinical studies are warranted to evaluate the implementation of CBD-based synergistic adjuvant therapies for breast cancer.  相似文献   

14.
Strong and durable adhesive bonds may be made between polytetrafluoroethylene (PTFE) and either cyanoacrylate (CA) or epoxy adhesives, if the PTFE surface is modified by the use of a “primer” such as triphenylphosphine (TPP) or diaminodiphenylmethane (DDM). The primer mixes with the PTFE surface, and the modified surface is then capable of forming an interphase, tens to hundreds of nanometers thick, where interpenetration of the adhesive and adherend occurs. Using CA adhesives, PTFE/CA/PTFE block compression shear bond strength (ASTM D4501-85) of over 10 MPa can be achieved, with failure occurring cohesively. Initial work with epoxy adhesives indicates that the use of DDM primer gives adhesive bonds comparable in strength with those produced by modification of the fluoropolymer surface by sodium naphthalenide.  相似文献   

15.
Cold plasma (CP) technology is a technique used to change chemical and morphological characteristics of the surface of various materials. It is a newly emerging technology in agriculture used for seed treatment with the potential of improving seed germination and yield of crops. Wheat seeds were treated with glow (direct) or afterglow (indirect) low-pressure radio-frequency oxygen plasma. Chemical characteristics of the seed surface were evaluated by XPS and FTIR analysis, changes in the morphology of the seed pericarp were analysed by SEM and AFM, and physiological characteristics of the seedlings were determined by germination tests, growth studies, and the evaluation of α-amylase activity. Changes in seed wettability were also studied, mainly in correlation with functionalization of the seed surface and oxidation of lipid molecules. Only prolonged direct CP treatment resulted in altered morphology of the seed pericarp and increased its roughness. The degree of functionalization is more evident in direct compared to indirect CP treatment. CP treatment slowed the germination of seedlings, decreased the activity of α-amylase in seeds after imbibition, and affected the root system of seedlings.  相似文献   

16.
通过脱醇法在凹凸棒土(ATP)表面接枝γ-氨丙基三乙氧基硅烷(APTES)实现氨基化(ATP-APTES),再经酰胺化反应接枝α-溴代异丁酰溴,从而在ATP表面固载ATRP引发基团(ATP-Br);最后以2,2-偶氮二异丁腈(AIBN)和ATP-Br为双组分引发体系进行正反向同时引发原子转移自由基聚合(SR&NI ATRP)制备ATP接枝聚苯乙烯杂化粒子(ATP@PS)。结果表明AIBN结合ATP-Br引发体系进行SR&NI ATRP具有活性/可控聚合的特征,随催化剂用量增大,体系过早偏离一级动力学行为。聚合温度在80℃,投料比为单体/催化剂/AIBN/ATP-Br=200/0.3/0.05/0.5的条件下,接枝聚合物和游离聚合物分子量差异随转化率(c)增大逐渐增加,转化率为31.1%时,两者分子量分布(PDI)均保持在1.54以下,ATP-Br表面ATRP引发基团的引发效率为6.3%。杂化粒子在PS基体中分散得到明显改善。  相似文献   

17.
Hypoxia–ischemia (HI)-related brain injury is an important cause of morbidity and long-standing disability in newborns. We have previously shown that human plasma-derived inter-alpha inhibitor proteins (hIAIPs) attenuate HI-related brain injury in neonatal rats. The optimal dose of hIAIPs for their neuroprotective effects and improvement in behavioral outcomes remains to be determined. We examined the efficacy of 30, 60, or 90 mg/kg of hIAIPs administered to neonatal rats after exposure to HI for 2 h. Postnatal day 7 (P7) Wistar rats were exposed to either sham-surgery or unilateral HI (right carotid artery ligation, 2 h of 8% O2) brain injury. A placebo, 30, 60, or 90 mg/kg of hIAIPs were injected intraperitoneally at 0, 24 and 48 h after HI (n = 9–10/sex). We carried out the following behavioral analyses: P8 (righting reflex), P9 (negative geotaxis) and P10 (open-field task). Rats were humanely killed on P10 and their brains were stained with cresyl violet. Male extension/contraction responses and female righting reflex times were higher in the HI placebo groups than the sham groups. Female open-field exploration was lower in the HI placebo group than the sham group. hIAIPs attenuated these behavioral deficits. However, the magnitude of the responses did not vary by hIAIP dose. hIAIPs reduced male brain infarct volumes in a manner that correlated with improved behavioral outcomes. Increasing the hIAIP dose from 30 to 90 mg/kg did not further accentuate the hIAIP-related decreases in infarct volumes. We conclude that larger doses of hIAIPs did not provide additional benefits over the 30 mg/kg dose for behavior tasks or reductions in infarct volumes in neonatal rats after exposure to severe HI.  相似文献   

18.
Discovery of the microbiota-gut–brain axis has led to proposed microbe-based therapeutic strategies in mental health, including the use of mood-altering bacterial species, termed psychobiotics. However, we still have limited understanding of the key signaling pathways engaged by specific organisms in modulating brain function, and evidence suggests that bacteria with broadly similar neuroactive and immunomodulatory actions can drive different behavioral outcomes. We sought to identify pathways distinguishing two psychoactive bacterial strains that seemingly engage similar gut–brain signaling pathways but have distinct effects on behaviour. We used RNAseq to identify mRNAs differentially expressed in the blood and hippocampus of mice following Lacticaseibacillus rhamnosus JB-1, and Limosilactobacillus reuteri 6475 treatment and performed Gene Set Enrichment Analysis (GSEA) to identify enrichment in pathway activity. L. rhamnosus, but not L. reuteri treatment altered several pathways in the blood and hippocampus, and the rhamnosus could be clearly distinguished based on mRNA profile. In particular, L. rhamnosus treatment modulated the activity of interferon signaling, JAK/STAT, and TNF-alpha via NF-KB pathways. Our results highlight that psychobiotics can induce complex changes in host gene expression, andin understanding these changes, we may help fine-tune selection of psychobiotics for treating mood disorders.  相似文献   

19.
阿尔兹海默病(老年性痴呆,AD)是由β淀粉样蛋白(Aβ)和微管相关蛋白(Tau)聚集形成的具有毒性作用的寡聚物而引起的老年人主要以记忆力下降和脑部形成老年斑、神经纤维缠绕为特征的神经退行性疾病. 小胶质细胞作为中枢神经系统中的固有免疫细胞,是脑内免疫监视的关键成分,发挥内源性免疫防御作用. 正常生理状态的小胶质细胞能有效吞噬和清除毒性Aβ寡聚体,阻止AD发生. 在AD病理过程中,过度激活的小胶质细胞通过补体依赖途径过度吞噬突触,导致突触丧失,同时大量释放炎症因子,促进Tau相关病理变化,对神经元造成直接损伤,导致认知功能下降. 由此可见,小胶质细胞在AD发生发展过程中起着双刃剑的作用,探明小胶质细胞的极化状态及其在AD疾病机理中的作用将为攻克AD的药物研发提供突破性思路.  相似文献   

20.
Inflammation plays a central role in the pathogenesis of knee PTOA after knee trauma. While a comprehensive therapy capable of preventing or delaying post-traumatic osteoarthritis (PTOA) progression after knee joint injury does not yet clinically exist, current literature suggests that certain aspects of early post-traumatic pathology of the knee joint may be prevented or delayed by anti-inflammatory therapeutic interventions. We discuss multifaceted therapeutic approaches that may be capable of effectively reducing the continuous cycle of inflammation and concomitant processes that lead to cartilage degradation as well as those that can simultaneously promote intrinsic repair processes. Within this context, we focus on early disease prevention, the optimal timeframe of treatment and possible long-lasting sustained delivery local modes of treatments that could prevent knee joint-associated PTOA symptoms. Specifically, we identify anti-inflammatory candidates that are not only anti-inflammatory but also anti-degenerative, anti-apoptotic and pro-regenerative.  相似文献   

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