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 共查询到20条相似文献,搜索用时 125 毫秒
1.
EXPERIMENTALINVESTIGATIONOFKINETICANDTRANSPORTPARAMETERSINAWALL-COOLEDFIXED-BEDREACTORZhen-MinCHENGandWei-KangYUAN(UNILABRese...  相似文献   

2.
国内外增强用玻璃纤维的现状与发展   总被引:1,自引:0,他引:1  
国内外增强用玻璃纤维的现状与发展林树益,高建枢,朱晶莹(南京玻璃纤维研究设计院210012)STATUSANDDEVELOPMENTOFREINFORCEDGLASSFIBERATHOMEANDABROAD¥LinShuyi;GaoJianshu;Z...  相似文献   

3.
1—2折流换热器流体温度沿程变化及其LMTD的计算   总被引:1,自引:0,他引:1  
1-2折流换热器流体温度沿程变化及其LMTD的计算梁日忠THEVARIATIONOFFLUIDTEMPERATUREALONGSIDPASSANDTHECALUATIONOFLMTDIN1-2BAFFLEHEATEXCHANGER1前言换热器设计中,...  相似文献   

4.
LARGESCALEPURIFICATIONOFPHOSPHOGLYCERATEKINASE(PGK)ANDGLYCERALDEHYDE3-PHOSPHATEDEHYDROGENASE(GAPDH)FROMYELLOWPEASBYPEG/REPPAL...  相似文献   

5.
THEORETICALSTUDIESONREACTIONSELECTIVITYIMPROVEMENTFORREDUCTIONOFNITROBENZENEINAPACKED-BEDELECTRODEREACTORUNDERPERIODIC-CURREN...  相似文献   

6.
SEMICONDUCTINGPOLYMERDEVICES:NEWDEVELOPMENTSYUGANG(InstituteforPolymersandOrganicSolidsUniversityofCaliforniaatSantaBarbara,S...  相似文献   

7.
THEPREPARATIONOFHIGH-PURITY,ULTRAFINEANDMONODISPERSEDTITANIUMDIOXIDEPOWDERFROMTITANIUMTETRACHLORIDEBYHYDROLYSISOFTITANIUMALKO...  相似文献   

8.
STRUCTURALANDPHOTOELECTRICPROPERTIESOFANOVELAMPHIPHILICZINCPHTHALOCYANINEMIXEDLBMULTILAYERS¥LIHongwu;CHENTiefeng;WANGHanhui;Z...  相似文献   

9.
稀土对聚氯乙烯(PVC)的热稳定作用李昕THERMALSTABILIZATIONOFRAREEARTHSONPVC1前言聚氯乙烯(PVC)是世界五大通用塑料之一,1987年,FVC树脂产量约600kt,制成品约800kt,1990年PVC树脂产量将近...  相似文献   

10.
国内外汽车玻璃钢市场的现状与展望   总被引:1,自引:0,他引:1  
国内外汽车玻璃钢市场的现状与展望李湘洲(长春建筑材料工业学校130022)CURRENTSITUATIONANDPROSPECTOFMARKETFORAUTOMOBILEFRPATHOMEANDABROAD¥LiXisligzhou(Changchu...  相似文献   

11.
The effects of rubber particle size and rubber/matrix adhesion on the impact properties of a brittle polymer have been separated using polystyrene (PS)/acrylonitrile-butadiene rubber (NBR) as a model system in which interfacial chemical reaction could be controlled. It has been proven that the interfacial adhesion between the rubber phase and the PS matrix not only greatly aids in reducing the rubber particle size but also plays a further role in improving the impact properties of the matrix polymer. The impact energies of PS/NBR blends with interfacial chemical bonding are four to ten times as high as those without interfacial bonding for the same average rubber particle size. However, at temperatures below the glass transition temperature of the rubber, there is no difference in impact energies with or without interfacial chemical bonding. It has been found that the optimum rubber particle size for toughening PS is influenced by interfacial adhesion. Smaller optimum rubber particle size is observed for blends with greater amounts of interfacial chemical bonding.  相似文献   

12.
赵祥迎  柴大程 《聚氯乙烯》2010,38(10):12-15,27
采用机械共混法和乳液共沉法制备了NBR/PVC共混胶,通过差示扫描量热仪(DSC)和场发射扫描电子显微镜(FE-SEM)对共混胶的微观形貌、结构进行了表征,考察了共混方式和共混胶配比对其力学性能的影响,并比较了共混胶、CPE、P-83对硬质/软质PVC的改性效果。结果表明:①与机械共混胶相比,乳液共沉胶混合得更均匀,分散性更好,其分子级混合程度更好;②乳液共沉胶试样的力学性能在总体上优于机械共混胶;③对于硬质PVC,CPE的改性效果优于其他改性剂;④对于软质PVC,乳液共沉胶的改性效果最好,特别是对撕裂强度的提高非常明显。  相似文献   

13.
相容剂对NBR/PP共混型热塑性弹性体性能的影响   总被引:9,自引:2,他引:9       下载免费PDF全文
考察了普通氯化聚乙烯(CPE)、高氯化CPE、马来酸酐接枝聚丙烯及复合氯化聚丙烯(CPP)等相容剂对NBR/PP共混体系性能的影响。试验结果表明,复合CPP是NBR/PP共混体系的理想相容剂,其最佳用量为6份;以此为相容剂的NBR/PP共混体系具有优良的热塑性,NBR/PP共混型热塑性弹性体可采用热塑性塑料通用的加工方法进行加工。  相似文献   

14.
The effect of chlorinated polyethylene (CPE) content and test temperature on the notched Izod impact strength and brittle‐ductile transition behaviors for polyvinylchloride (PVC)/CPE blends and PVC/CPE/nano‐CaCO3 ternary composites is studied. The CPE content and the test temperature regions are from 0–50 phr and 243–363 K, respectively. It is found that the optimum nano‐CaCO3 content is 15 phr for PVC/CPE/nano‐CaCO3 ternary composites. For both PVC/CPE blends and PVC/CPE/nano‐CaCO3 ternary composites, the impact strength is improved remarkably when the CPE content or test temperature is higher than the critical value, that is, brittle‐ductile transition content (CBD) or brittle‐ductile transition temperature (TBD). The TBD is closely related to the CPE content, the higher the CPE content, the lower the TBD. The temperature dependence of impact strength for PVC/CPE blends and PVC/CPE/nano‐CaCO3 ternary composites can be well simulated with a logistic fitting model, and the simulation results can be illustrated with the percolation model proposed by Wu and Jiang. DMA results reveal that both PVC and CPE can affect the TBD of PVC/CPE blends and PVC/CPE/nano‐CaCO3 composites. When the CPE content is enough (20 phr), the CPE is more important than PVC for determining the TBD of PVC/CPE blends and PVC/CPE/nano‐CaCO3 composites. Scanning electron microscopy (SEM) observations reveal that the impact fractured mechanism can change from brittle to ductile with increasing test temperature for these PVC systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

15.
本文用Brabender塑化仪,双锟开炼机研究了刚性有机粒子对PVC/CPE共混体熔融塑化为及力学性能的影响,探讨了不同加工温度对PVC/CPE共混体力学性能的影响,实验表明:添加少量刚性有机粒子后,体系的塑化时间缩短,塑化行为改善,韧性有较大幅度提高,拉伸强度有所改善,加工温度为160-180℃体系性能最好。  相似文献   

16.
本文研究刚性聚合物(PS、PMMA)对CaCO_2填充的PVC/CPE共混体力学性能和流变性能的影响。结果表明,刚性聚合物的填入提高了共混体的冲击强度,其中,对PVC/CPE/CaCO_3=100/15/10体系的增韧效果较好。PMMA使共混体的拉伸强度有所提高而PS使共混体拉伸强度下降。流变性的测定显示,Ca-CO_2使共混体的表观粘度和粘流活化能增加,牛顿的流动性增强,而在PVC/CPE/CaCO_3共混体中加入4.5份PS能明显降低共混体的表观粘度和粘流活化能,牛顿的流动性降低,但仍有良好的挤出物外观和较低的挤出膨胀率。  相似文献   

17.
Summary PB-g-MMA core-shell impact modifiers were synthesized by seed emulsion polymerization and impact-modified PMMA/PVC blends were prepared by melt blending PMMA, PVC and PB-g-MMA at 160 °C. The PB-g-MMA particles were dispersed uniformly in the PMMA/PVC matrix. PMMA/PVC blends were prepared in the blend ratio from 100/0 to 0/100 and the rubber content was kept 16% in all the compositions. The effects of matrix composition on the mechanical properties and morphology of the blends were studied. It was found that when the matrix was a PMMA-rich system, the sample broke in a brittle mode and crazing of the matrix was the main mechanisms of deformation. When the matrix was a PVC-rich system, the sample broke in a ductile mode and the main deformation mechanisms were cavitation of the particle and shear yielding of the matrix. There existed a transition from crazing to shear yielding in the rubber-modified PMMA/PVC blend as the matrix composition varied.  相似文献   

18.
有机刚性填料对PVC韧性的影响   总被引:4,自引:0,他引:4  
用拉伸实验和冲击实验研究了聚甲基丙烯酸甲酯(PMMA)、聚苯乙烯(PS)等有机刚性填料(ROF)对聚氯乙烯(PVC)韧性的影响。实验表明PMMA、PS对PVC具有一定的增韧作用,并且其增韧机理与弹性体增韧不同。  相似文献   

19.
研究了氯化聚乙烯对EPDM/NBR并用胶物理机械性能的影响。结果发现,加入氯化聚乙烯后,并用胶的混合平衡扭矩降低,达到平衡扭矩所需的时间缩短,且无论用硫黄硫化还是用过氧化物硫化,硫化胶的物理机械性能都提高,表明氯化聚乙烯对EPDM/NBR并用胶有一定的增容作用。同时也发现用过氧化物硫化的EPDM/NBR并用胶物理机械性能优于硫黄硫化的并用胶物理机械性能。  相似文献   

20.
CPE/NBR并用胶硫化体系的研究   总被引:1,自引:1,他引:1       下载免费PDF全文
讨论了硫化反应活化能与并用胶性能之间的关系。根据阿累尼乌斯公式,求出CPE/NBR并用胶硫化反应活化能。结果发现,当该活化能与CPE或NBR单一胶相在同一硫化体系下硫化的活化能十分接近时,并用胶的物性可以达到两种胶料物性的加和水平。硫脲一硫黄—超速促进剂硫化体系适用于CPE/NBR并用胶,当并用比为80:20时,硫化胶具有良好的耐油性和强伸性能。  相似文献   

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