共查询到19条相似文献,搜索用时 78 毫秒
1.
通过将同轴圆柱环隙流动简化为平面运动流动,在单胞模型的基础上建立了振动力场作用下不相容聚合物共混物能耗速率和能量比的计算公式。从而可以基于能量比模型的概念对影响共混体系相形态的因素进行研究。计算结果表明,聚合物加工过程中引入振动力场为共混体系相形态控制提供了更为有效手段。 相似文献
2.
何郁嵩;黄亚江;李光宪 《中国塑料》2010,24(10):21-27
介绍了流场下不相容聚合物共混物分散相形态及演变研究进展,并指出这是获得性能优异共混材料的关键。在流场下,不相容共混物分散相尺寸由破碎和凝聚等动力学过程决定。鉴于模型的理想化,早期研究主要针对牛顿流体,且分散相的变形、破碎和凝聚等理论均发源于此。对于聚合物共混物,其在本质上与牛顿流体有很多相似之处,然而,独特黏弹性质却是影响其相形态的重要因素。最后,对一些预测分散相尺寸的理论模型进行了总结,并重点讨论了分散相浓度、聚合物弹性、增容和填料等因素对流场下分散相形态的影响。 相似文献
3.
4.
5.
增容剂在聚合物共混物中对界面张力、相形态及力学性能的影响张剑锋译卢秀萍校本文研究了四种聚合物共混体系(PE/PS、PE/PA—6、PS/PA—6及PS/PET)的界面张力、相形态及相畴增加。通常较高的界面张力与粗化的相形态及快速的相连接相对应。这些双... 相似文献
6.
周炳斌;马秀清;黄凤春;梁文虎 《中国塑料》2011,25(8):94-98
对啮合同向双螺杆挤出机熔体输送段6种不同螺杆构型所形成的流场进行了数值模拟,并进行了实验研究。结果表明,增大回流系数能增强共混物的分布混合效果,并且回流系数越大,分布混合效果越好。 相似文献
7.
8.
9.
10.
采用熔融共混法制备了聚丙烯/三元乙丙橡胶(PP/EPDM)共混物,利用力学性能测试、SEM和TG分析等手段考察了抗氧剂对共混物热氧稳定性、光稳定性、力学性能和微观结构的影响。结果表明:抗氧剂1010和抗氧剂168的加入,提高了PP/EPDM共混物的耐候性,细化了分散相的尺寸,改善了共混物的力学性能。 相似文献
11.
12.
13.
14.
Effect of Inorganic Filler Phase on Mechanical and Morphological Properties of Binary Immiscible Polymer Blends 总被引:1,自引:0,他引:1
Summary
A ternary composite composed of two immiscible organic phases, polypropylene (PP) and polyamide-6 (PA), and talc as inorganic
filler is studied in terms of mechanical properties and microstructure. Effect of different filler levels (10-30 5% by weight)
on tensile and flexural properties of each polymeric phase is examined while special attention is paid to immiscible PPPA
blend. Mutual effect of compatibilizer and filler on properties is searched by selecting maleic anhydride grafted polypropylene
(MA-g-PP) as compatibilizer. It is observed from SEM studies that inhomogeneous, course and elongated morphology of uncompatibilized
composites is changed to well dispersed, fine and more homogeneous particle-in-matrix morphology via additional compatibilization
effect. This unique microstructure is believed to be responsible for the improved tensile and flexural properties in blend
composites.
Received: 19 June 2002/Accepted: 19 January 2003
Correspondence to Nihan Nugay 相似文献
15.
《分离科学与技术》2012,47(8):1933-1954
Abstract Ultrafiltration techniques have particular advantages for simultaneous purification, concentration, and fractionation of macromolecules. A comparative study is presented on novel ultrafiltration polymeric blend membranes based on cellulose acetate (CA) prepared in the absence and presence of polymeric additives such as polyethylene Glycol 200 (PEG) and polyvinylpyrrolidone (PVP) by phase inversion technique using N,N′-dimethylformamide (DMF) as solvent. Polymer blend composition, additive concentration and casting, and gelation conditions were standardized for the preparation of asymmetric membranes by pore statistics and morphology. These blend membranes were characterized for compaction in ultrafiltration experiments at 414 kPa pressure in order to attain steady state flux and is reached within 4–5 h. The pure water flux was measured at 345 kPa pressure. Membrane hydraulic resistance derived by measuring water flux at various transmembrane pressures and found to be inversely proportional to pure water flux. Water content is estimated by simple drying and weighing procedures and found proportional to pure water flux for all the membranes. The molecular weight cut-offs (MWCOs) of different membranes were determined with proteins of different molecular weights and found to vary from 20 to 69 kDa depending on the PEG 200 and PVP content in the blend in the casting solution. Skin surface porosity of the membranes was analyzed by scanning the samples at various magnifications. The characterized CA, CA/PEG200 and CA/PVP membranes were used for cadmium ion rejection studies at 345 kPa. 相似文献
16.
采用本体聚合法合成具有一定转化率的热塑性聚合物TP ,并将其与不饱和聚酯 (UP)树脂混合 ,对所得混合树脂体系的流变性能、收缩性能、力学性能等进行了研究 ;利用动态力学方法分析了体系中热塑性聚合物与UP树脂的相容性 ,并对混合树脂体系进行了光学微观结构和红外光谱分析。结果表明 :TP与UP树脂间有一定的相容性 ,但并不完全相容 ;当UP树脂中加入TP 5份时 ,体系的粘度由 3Pa·s降为 2 5 5Pa·s ,收缩率由 1 77%降为1 45 % ;而加入 10份的TP ,树脂粘度降为 1 8Pa·s ,收缩率降为 1 3 9%。另外 ,体系的弯曲强度随TP加入量的提高而增加 ,但冲击强度的变化却呈先增加后降低的趋势。 相似文献
17.
18.
Yao-Xue Du 《Polymer-Plastics Technology and Engineering》2013,52(8):971-977
The formulas of polymer melt velocity, shearing rate, and shearing stress in simple shearing flow under the vibration force field were established. Based on the concept of an energy ratio model, the rate of energy dissipation and the energy ratio for blending systems are expressed theoretically. The calculated and analytical results of both the dynamic flow field and energy ratio show that with the increasing of vibration strength the fluctuating shearing force field exerted on polymer melt and the negative pressure diffusion behavior of instantaneous impulse strengthen. The energy consumption for phase inversion of immiscible polymer blends under the vibration force field is less than that of steady state. The parameter controllability of the vibration force field provides a more effective method for realizing phase inversion of immiscible polymer blends. 相似文献
19.
硅烷接枝交联LDPE、LLDPE及其共混物的结构研究 总被引:4,自引:0,他引:4
利用红外光谱、凝胶渗透色谱、热延伸试验、差示扫描量热法、扫描电子显微镜等方法研究了低密度聚乙烯(LDPE)、线型低密度聚乙烯(LLDPE)及其共混物的乙烯基硅烷接枝及交联产物的分子结构、熔融行为和形态。结果表明:硅烷接枝后,LDPE、LLDPE的重均摩尔质量小幅增加;硅烷接枝交联能力为:LLDPE〉LDPE/LLDPE共混物〉LDPE;接枝和交联使LDPE、LLDPE及其共混物的结晶度降低,晶粒变得不均匀;硅烷接枝和交联能增加LDPE/LLDPE共混物的相容性;交联结构提高了LDPE、LLDPE及其共混物的抗冲性。 相似文献