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1.
通过IR、DSC、TG、TEM、溶胀比测定等方法,对丙烯酸丁酯-苯乙烯-甲基丙烯酸甲酯(BA-St-MMA)交联共聚物的结构和EP/P(BA-St-MMA)Semi-LIPN(EP为环氧树脂)的结构、热稳定性、溶胀性及乳胶膜的吸水性、乳胶粒形态进行了研究。结果表明,BA-St-MMA共聚物中主要是无规共聚物,也含有嵌段或接枝共聚的链段,但并不太长;当该Semi-LIPN受热时,其中的EP因未交联而先行分解;EP的加入使乳胶膜的吸水性降低;在乳胶粒的测试过程中,由于分散程度不同还观察到了网络结构。  相似文献   

2.
通过IR,DSC,TG,TEM溶胀比测定等方法,对丙烯酸丁酯-苯乙烯-甲基丙烯酸甲酯(BA-St-MMA)交联共聚物的结构和EP/P(BA-St-MMA)Semi-LIPN(EP为环氧树脂)的结构,热稳定性,溶胀性及乳胶膜的吸水性,乳胶粒开形态进行了研究。结果表明:BA-St-MMA共聚物中主要是无规共聚物,也含有嵌段或接枝共聚链段,但并不太长;当该Semi-LIPN受热时,其中的EP因未交联而先  相似文献   

3.
通过乳液共聚合分别合成了两种具有互补结构的共聚物乳液:聚(甲基丙烯酸甲酯-丙烯酸丁酯-甲基丙烯酸聚P(MMA-BA-MMA)和聚(甲基丙烯酸甲酯-丙烯酸丁酯-乙烯基吡咯烷酮)P(MMA-BA-VP)。通过^1H-NMR测定,研究了共聚物组成与单体投料组成的关系;通过FR-IR、DSC、表 及力学性能测试,研究了P(MMA-BA-MMA)/P(MMA-BA-VP)共聚物复合体系氢键相互作用及其对聚合物性能的影响,结果表明P(MMA-BA-MMA)/P(MMA-BA-VP)共聚物复合体系存在氢键相互作用,氢键相互作用导致复合体系表面降低、拉伸强度提高。  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.
甲基丙烯酸β-羧乙酯(HEMA)和丙烯酸长链烷基酯(RA)的自由基共聚合是80℃二氧六环为溶剂,使用过氧化苯甲酰(BPO)为引发剂聚合而成,采用了IR、DSC、SEM等手段研究了该共聚物的结构与性能的关系。实验结果表明该共聚物的吸水性随共聚物中亲水基的增加而增加。  相似文献   

6.
MCS接枝共聚物的结构和形态   总被引:4,自引:0,他引:4  
将甲基丙烯酸甲酯(MMA)、苯乙烯(S)在氯化聚乙烯(CPE)存在下进行悬浮接枝共聚,获得MCS树脂。本文着重考察了MCS树脂的化学结构及胶粒形态。结果表明,确实发生了接枝共聚。CPE用量、RSH含量、引发剂浓度、反应温度、溶胀时间及聚合转化率对MCS树脂的接枝率、接枝效率均有影响。MCS树脂是接枝共聚物、MMA/S共聚物与MMA均聚物的混合物,橡胶相CPE在MCS树脂中的分散情况为“海岛结构”,  相似文献   

7.
AMPS/AM共聚物的低温合成和性能   总被引:18,自引:0,他引:18  
选用氧化-还原引发体系进行了AMPS/AM的低温共聚合反应,研究了反应温度、引发剂浓度、AMPS和AM单体的浓度和组成对聚合反应和产物的影响。通过反应条件和反应组成的优化,获得了高分子量(106~107)和高线性规整性的AMPS/AM共聚物ACP-Ⅱ系列产品,测定了它们盐水溶液的不同性能。结果表明,ACP-Ⅱ共聚物具有突出的增粘作用和对高温高盐作用的稳定性。  相似文献   

8.
PBA/αMS-AN核壳乳液共聚反应的研究   总被引:1,自引:0,他引:1  
以聚丙烯酸丁酯(PBA)为核,用石油化工副产物α-甲基苯乙烯(αMS)代替通常使用的苯乙烯(St)或甲基丙烯醚甲酯,利用其成本低,本身不易均聚,但易与丙烯腈(AN)共聚的原理用其共聚物作为壳层,采用分段乳液聚合法,得到了具有PBA/αMS-AN核壳结构的高分子复合乳液。通过大量实验确定了聚合反应配方及加科方式,通过红外分析法(IR)、透射电镜法(TEM)、差热分析法(DSC)等手段,对该共聚物结构进行了表征,确认了该共聚物为核壳型结构。  相似文献   

9.
合成了甲基丙烯酸甲酯,苯乙烯与甲基丙烯酰氧基-顺丁一酸单异丙酯酰氧基-异丙氧基铝的共聚物P(MMA-MMPA)和P(St-MMPA)。研究了共聚物的红外光谱,扫描电镜,热分析,荧光光谱,透光率,折光率及力学性能,取得了较为满意的结果。  相似文献   

10.
用小角X射线散射(SAXS)法研究了聚甲基烯酸β关羟乙酯(HEMA)在聚乙烯(PE)膜上辐照接枝物的形态结构。采用Tsvankin模型和Buchanan改进的SAXS分析方法,测定了HEMA/PE辐照接枝物的长周期,晶片厚度,无定形厚度及-维结晶度等参数。发现HEMA/PE接枝物存在着两种长周期及两组不同的形态结构参数。笔者提出了“双重夹层结构”模型,对该接枝物的形成机理作了讨论。  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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