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1.
聚醚型多嵌段聚氨酯与氯化聚氯乙烯共混物的相容性 …   总被引:2,自引:0,他引:2  
DSC及FT-IR方法研究了聚四亚甲基醚型多嵌段聚氨酯与氨化聚氯乙烯共混物的相容性。结果表明,共混物具有两个分立的Tg,属不相容体系。多嵌段聚氨酯硬段含量的增加,加强了SPU分子间的相互作用,同时也减小了共混物两组分的相容性。  相似文献   

2.
采用示差扫描量热法研究了相同硬段及含量的3种不同类型软段的聚氨酯与聚氯乙烯(PVC)、氯化聚氯乙烯(CPVC)的相容性。结果表明,多嵌段聚氨酯与PVC、CPVC的相容性次序为:PCL-PUPTMO-PU>PPO-PU,而PVC和CPVC在共混体系中具有相似的相容行为  相似文献   

3.
多嵌段聚氨酯与PVC与CPVD共混体系相容性的研究   总被引:1,自引:0,他引:1  
采用示差扫描量热法研究了相同硬段及含量的3种不同类型软段的聚氨酯与聚氯乙烯(PVC)、氯化聚氯乙烯(CPVC)的相容性。结果表明,多嵌段聚氨酯与PVC、CPVC的相容性次序为:PCL-PU〉〉PTMO-PU〉PPO-PU,而PVC和CPVC在共混体系中具有相似的相容行为。  相似文献   

4.
PVA-CS共混体系相容性的研究   总被引:2,自引:0,他引:2  
利用DSC等方法,研究了PVA-CS二元共混体系的相容性。结果表明,PVA与CS之间存在一定的相互作用,为部分相容体系。以Flory-Huggins的高分子溶液理论为基础,通过Wood或Fox方程,计算出不同共混比的PVA-CS共混体系两相中二组分的表现质量分率,进而计算出体系的聚合物-聚合物Floy-Huggins相互作用参数χ_(12)或g_(12),对PVA-CS共混体系的相容性进行了验证。  相似文献   

5.
CA/PAN共混体系相容性的研究   总被引:5,自引:0,他引:5  
应用DSC、SEM、FT-IR等方法,研究了CA-PAN、CA-PAN-To二元和三元混溶液的相容性。结果表明,CA和PAN存在一定的相互作用,有部分相容性。改变共混比例,共混膜具有不同微相区的两相结构,To有助于提高两组分的相容性。  相似文献   

6.
确定聚合物共混的相容性最常用的方法是通过测定共混物的玻璃化转变温度(Tg),本文利用DSC-7(Epson)测定了不同共混比的PVA,CS共混物的玻璃化转变温度,结果表明PVA,CS之间有良好的相容性。本文利用扫描电子显微镜(SEM),红外光谱(IR)和X-射线衍射(XRD)等现代分析仪器,对研制的多元酸交联的PVA-CS/PSF膜结构进行了观察测试,探讨了膜结构与性之间的关系。  相似文献   

7.
PVA—CS共混体系相容性的研究   总被引:1,自引:0,他引:1  
利用DSC等方法,研究了PVA-CS二元共混体系的相容性。结果表明,PVA与CS之间存在一定的相互作用为部分相容体系,以Flory-Huggins的高分子溶液理论为基础,通过Wood或Fox方程,计算出不同共混出PVA-CS共混体系两相中二组分的表面质量分率,进而计算出体系的聚合物-聚合物Floy-Huggins相互作用参数,x12或g12,对PVA-CS共混体系的相容性进行了验证。  相似文献   

8.
通过DSC、TG考察了反应注射成型(聚氨酯-聚苯乙烯)间充复合弹性体各相态间的相互作用及其热降解规律。结果表明,PUR交联密度提高有利于其软段相与PS相形成部分互溶的微相结构,而NCO/OH的提高则促进软段的微相分离及增大PS与PUR的相容性。该共混体系的热裂解属无规热降解反应,不同热裂解温度区域内各相态的热失重均有所偏重。  相似文献   

9.
紫外线辐照HDPE与尼龙-6相容性的研究   总被引:2,自引:0,他引:2  
采用IR、SEM、DSC和拉伸应力-应变曲线研究了紫外线辐照HDPE/PA6的相容性,结果表明,随紫外线辐照时间的增长,HDPE分子链上引入C=O-C-O-等极性基团明显增加;PA6的粒径减小,与基体间界面作用加强;两组分玻璃化温度差(T_(g,PA6)-T_(g,HDPE))减小;共混物拉伸应力-应变曲线上出现屈服点及拉伸冷流塑性形变。当辐照时间达144h后,由于HDPE热稳定性明显变差,共混物韧性突降,拉伸应力-应变曲线上未出现屈服点。  相似文献   

10.
PPS/PA-66共混物结构与性能的研究   总被引:8,自引:0,他引:8  
用X射线衍射、SEM和FT-IR研究了PPS/PA-66共混物的聚集态结构、相形态和共混体系分子间的相互作用。结果表明,随着PA-66含量增大,共混物的结晶性更好;PPS/PA-66共混体系属于多相体系,含微量支化或交联键的PPS占50%时,为分散相,PA-66占75%时,PPS成为连续相;随着PA-66含量增加,PPS的苯环C-H振动705cm-1峰位向低波数移动,随PPS含量增加,PA-66中酰胺的C=O1639cm-1峰位向低波数移动,酰胺基团与苯环上的C-H存在氢键相互作用。熔融流动性、流变性和冲击性能试验证明,共混物有良好的熔融流动性和韧性。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

13.
14.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

15.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

16.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

17.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

18.
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...  相似文献   

19.
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from  相似文献   

20.
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.  相似文献   

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