釜内聚合法制备间规聚苯乙烯与聚丙烯共混复合材料

采用MgCl2 TiCl4 β 二酮 MAO催化体系合成间规聚苯乙烯 (sPS)与等规聚丙烯 (iPP)共混复合材料 .对催化剂的活性和共混复合材料的组成随Al∶Ti和聚合温度的变化进行了表征 ,催化剂的活性可达 1.5× 10 5gB[molTi·h]- 1 ,sPS的含量可控制在 5 5 %～ 82 % .采用示差量热扫描仪 (DSC)和扫描电镜 (SEM)

釜内聚合法制备β晶型聚丙烯

利用小本体聚丙烯(PP)聚合装置及技术,将β成核剂于丙烯聚合前加入聚合釜中,实现了具有较高β晶含量PP的釜内在线制备。当β成核剂含量较低时,催化剂活性无显著降低,PP的相对分子质量及其分布也变化不大。当成核剂质量分数在0.08%～0.12%时,利用广角X射线衍射测试的PP中β晶的相对含量可达85%。差示扫描量热法分析及力学性能测试表明:β晶型PP的结晶速率明显高于不含β成核剂的普通PP,且具有良好的韧性。

国内聚合MDI市场货源偏紧

10月是建筑产业、氨纶业等MDI下游终端市场的需求旺季,而随着家电下乡和汽车下乡政策的继续推行,家电中的冰箱冷柜、汽车座垫等行业对聚合MDI的需求将得到增长。随着欧美经济的复苏,国内的出口开始恢复,特别是纺织。

PAN基凝胶聚合物电解质双电层电容器

为了得到安全、无泄漏、微型、超薄型的双电层电容器,采用内聚合方法制得聚丙烯腈基凝胶聚合物电解质双电层电容器,电解质的增塑剂为碳酸丙烯酯和碳酸乙烯酯,支持电解质为高氯酸锂,电极材料分别为比表面积1000m2/g和2600m2/g的活性炭。采用交流阻抗、循环伏安、恒流充放电、循环寿命等测试方法对内聚合式凝胶聚合物电解质及其组成的双电层电容器的性能进行了测试。结果表明,此种方法制得的双电层电容器的内阻小,比容量较大,其中以比表面积2600m2/g活性炭为电极材料的电容器的双电极比容量达到47.41F/g。

8月聚合MDI市场报告

一、市场行情简述本月行情:8月,国内聚合MDI市场大幅上涨,月末市场弱稳为主。月初,场内日韩货价格偏低,但近洋美金价格很快反弹,相对高企。另聚合MDI厂家上调挂牌价,并限量供应,拜耳装置运行不稳定,于月中停止供货一周,支撑市场看涨心态,价格持续上扬,下游接货意愿一般,谨慎观望,市场缺乏上涨动力,下旬,市场高位盘整为主。然下游需求回暖缓慢,月末,有部分聚合MDI持货商开始低价出货,市场价格亦小幅下跌。

9月聚合MDI市场报告

一、市场行情简述本月行情:9月,国内聚合MDI市场持续阴跌,月末市场弱势整理为主。月初,各聚合MDI厂家挂牌价颇高,受8月份高价支撑,再加上日本NPU装置和万华烟台装置检修,支撑市场看涨心态,价格坚挺,但下游接货意愿一般,谨慎观望,市场缺乏上涨动力,下旬,市场持续阴跌为主。下游需求平平,月末,有部分聚合MDI持货商开始积极出货,市场价格亦继续阴跌。

10月聚合MDI市场报告

一、市场行情简述本月行情:10月,国内聚合MDI市场持续弱势运行,价格处于不断阴跌中。月初,各聚合MDI厂家挂牌价较上月大幅下调,9月底,烟台万华装置重启,10月中旬,日本南阳装置重启,加上10月建筑保温行业采购结束,市场刚需为主,这一系列因素导致聚合MDI持货商开始积极出货,市场价格亦继续阴跌,再加上巴斯夫10月低结算的出台。

釜内制备β晶型聚丙烯

制备了传统的Ziegler-Natta催化剂,研究了采用釜内聚合添加β成核剂和采用釜外共混时添加β成核剂制备的β晶型聚丙烯(β-PP)的性能,结果发现:两种方法制备的PP中β晶含量都有所提高,产品的热变形温度及悬臂梁缺口冲击强度均有所改善。当釜内添加的β成核剂为430μg/g时,悬臂梁缺口冲击强度提高了30%左右,热变形温度提高了27℃左右。与釜外共混制备β-PP相比,釜内添加β成核剂制备β-PP时β成核剂用量更少,成核效果更显著。釜内添加154μg/g的β成核剂,其成核效果要好于釜外共混添加191μg/g的β成核剂。

β晶等规聚丙烯的制备原理和研究进展

β晶等规聚丙烯(β-iPP)作为聚丙烯树脂的重要品种,具有优良的抗冲击性能、延展性能和高的热变形温度,在管材、薄膜、微波加热容器等领域有着广泛应用。β-iPP特有的球晶结构、βα-再结晶现象和β-α晶型转变特性等是赋予其优良性能的内在原因。综述了不同晶型聚丙烯特别是β-iPP的结构、性能特点及制备原理,重点介绍了成核剂共混法制备β-iPP的研究进展和趋势,并基于β-iPP的性能特点介绍了其主要应用领域,对β-iPP的发展趋势提出了展望。

硬模板法高温水热合成微孔-介孔二氧化硅及掺铝介孔二氧化硅

α-亚麻酸在加热条件下通过胶束内聚合可转化为能够耐受高温水热环境的介观模板,用此硬模板在高温水热条件下直接合成了微孔-介孔二氧化硅及掺铝介孔二氧化硅.用X射线衍射(XRD)、氮气吸附及透射电镜等手段对材料进行了表征.结果表明,所得材料在沸水中处理5 d后仍保持670 m2/g的比表面积.透射电镜和NLDFT孔径分析结果显示,所得材料同时具备介孔和微孔结构.29Si MAS NMR谱图显示,完全缩聚的Q4型硅是材料中主要的硅组分,致使材料具有高的水热稳定性.

INTERFACE DAMAGE ANALYSIS OF FIBER REINFORCED COMPOSITES WITH DUCTILE MATRIX

A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.

行业要览

正国内大部分生产企业装置开工恢复运行,负荷渐稳,但基本无库存,短期内依然较难满足紧张的TDI市场。十月亚洲己二酸价格可能进一步上涨据报道,由于原料价格上涨,加上传统需求旺季购买活动不断活跃,9、10月份亚洲己二酸价格可能会进一步上涨,业内人士九月初表示。据ICIS,自7月底以来近一个多月里,亚洲纯苯价格上涨了5%,

价格企稳回升聚氨酯产业机会显现

随着年末临近,市场对业绩的关注度逐渐升温,净利增长良好且近期主导产品价格回升的公司,市场认可度较高。作为今年市场表现优秀的化工品种,自年初至10月上旬,在厂家联手限产保价和下游需求相对稳定的支撑下,聚氨酯行业中的TDI、聚合MDI价格持续上行,行业盈利情况大幅改善。四季度以来在进口低价货源冲击和传统需求淡季的压制下,聚氨酯产品价格大幅下行,但仍高于全年平均水平。近期受益于市场货源偏紧和商家惜售情绪影响。

2012年8月份进出口海关数据分析

正聚合MDI根据税则号39093010统计,2012年8月份共进口产品量为20369吨,进口金额为44303747美元,平均进口单价2175美元/吨。8月份相比于7月份进口量16572吨增加22.91%。进口到货地主要为浙江省5714吨,上海市4693吨,江苏3570吨,这三省占总额的68.62%。1。

2013年1月份进出口海关数据分析

聚合MDI根据税则号39093010统计,2013年1月份共进口产品量为29154.7吨,进口金额为64695004.0美元,平均进口单价2219.0美元/吨。出口产品数量19543.3吨,出口金额为39757420.0美元,平均出口单价为2,034.3美元/吨。

Detection of PERV by polymerase chain reaction and its safety in bioartificial liver support system

AIM： To establish a method detecting porcine endogenous retrovirus （PERV） in China experimental minipigs and to evaluate the safety of PERV in three individuals treated with bioartificial liver support systems based on porcine hepatocytes. METHODS： Porcine hepatocytes were isolated with two-stage perfusion method, then cultured in the bioreactor, which is separated by a semipermeable membrane （0.2μm） from the lumen through which the patients＇ blood plasma was circulated. After posthemoperfusion, patients＇ blood was obtained for screening. Additionally, samples of medium collected from both intraluminal and extraluminal compartments of the laboratory bioreactor and culture supernate in vitro was analyzed. The presence of viral sequences was estimated by polymerase chain reaction （PCR） and reverse transcriptase-polymerase chain reaction （RTPCR）. Finally, the infection of virus in the supernate of common culture was ascertained by exposure to the fetal liver cells. RESULTS： PERV-specific gag sequences were found in the porcine hepatocytes using RT-PCR. and were detected in all samples from the intraluminal, extraluminal samples and culture supernate. However, culture supernatant from primary porcine hepatocytes （cleared of cellular debris） failed to infect human fetal liver cells. Finally, RT-PCR detected no PERV infection was found in the blood samples obtained from three patients at various times post-hemoperfusion. CONCLUSION： The assays used are specific and sensitive, identified by second PCR. PERVs could be released from hepatocytes cultured in bioreactor without the stimulation of mitogen and could not be prevented by the hollow fiber semipermeable membrane, indicating the existence of PERV safety in extracorporeal bioartificial liver support system （EBLSS）.

Determination of key parameters of Al–Li alloy adhesively bonded joints using cohesive zone model

The key parameters of the adhesive layer of a reinforcing patch are of great significance and affect the ability to suppress crack propagation in an Al–Li alloy patch-reinforced structure.This paper proposes a method to determine the key parameters of the adhesive layer of adhesively bonded joints in the Al–Li alloy patch-reinforced structure.A zero-thickness cohesive zone model(CZM)was selected to simulate the adhesive layer’s fracture process,and an orthogonal simulation was designed to compare against the test results.A three-dimensional progressive damage model of an Al–Li alloy patch-reinforced structure with single-lap adhesively bonded joints was developed.The simulation’s results closely agree with the test results,demonstrating that this method of determining the key parameters is likely accurate.The results also verify the correctness of the cohesive strength and fracture energy,the two key parameters of the cohesive zone model.The model can accurately predict the strength and fracture process of adhesively bonded joints,and can be used in research to suppress crack propagation in Al–Li alloy patch-reinforced structures.

CO2/CH4 separation using inside coated thin film composite hollow fiber membranes prepared by interfacial polymerization

Carbon dioxide(CO_2) is greenhouse gas which originates primarily as a main combustion product of biogas and landfill gas. To separate this gas, an inside coated thin film composite(TFC) hollow fiber membrane was developed by interfacial polymerization between 1,3–cyclohexanebis–methylamine(CHMA) and trimesoyl chloride(TMC). ATR-FTIR, SEM and AFM were used to characterize the active thin layer formed inside the PSf hollow fiber. The separation behavior of the CHMA-TMC/PSf membrane was scrutinized by studying various effects like feed gas pressure and temperature. Furthermore, the influence of CHMA concentration and TMC concentration on membrane morphology and performance were investigated. As a result, it was found that mutually the CHMA concentration and TMC concentration play key roles in determining membrane morphology and performance. Moreover, the CHMA-TMC/PSf composite membrane showed good CO_2/CH_4 separation performance. For CO_2/CH_4 mixture gas(30/70 by volume) test, the membrane(PD1 prepared by CHMA 1.0% and TMC 0.5%) showed a CO_2 permeance of 25 GPU and the best CO_2/CH_4 selectivity of 28 at stage cut of 0.1. The high CO_2/CH_4 separation performance of CHMA-TMC/PSf thin film composite membrane was mostly accredited to the thin film thickness and the properties of binary amino groups.

Delamination analysis of woven fabrication laminates using cohesive zone model

A new test method was proposed to evaluate the cohesive strength of composite laminates. Cohesive strength and the critical strain energy for Mode-II interlamiar fracture of E-glass/epoxy woven fabrication were determined from the single lap joint(SLJ) and end notch flexure(ENF) test, respectively. In order to verify their adequacy, a cohesive zone model simulation based on interface finite elements was performed. A closed form solution for determination of the penalty stiffness parameter was proposed. Modified form of Park-Paulino-Roesler traction-separation law was provided and conducted altogether with trapezoidal and bilinear mixed-mode damage models to simulate damage using Abaqus cohesive elements. It was observed that accurate damage prediction and numerical convergence were obtained using the proposed penalty stiffness. Comparison between three damage models reveals that good simulation of fracture process zone and delamination prediction were obtained using the modified PPR model as damage model. Cohesive zone length as a material property was determined. To ensure the sufficient dissipation of energy, it was recommended that at least 4 elements should span cohesive zone length.

In vitro toxicologic study of chitin short fiber reinforced polycaprolactone composite

Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morphology observation, MTT and DNA assay were used to evaluate the influence of the composite on the morphology, growth and proliferation of cultured L-929 cells. Results: The composite did not impair the morphology of cultured cells in vitro. MTT and DNA assay demonstrated that the growth and proliferation of the cultured cells were not significantly inhibited by the composite. Conclusion : The composites have fine cytocompatibility and are safe for clinical use of reconstruction of chest wall defects.