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1.
离聚物对PET/LDPE共混物的结构与性能研究   总被引:3,自引:0,他引:3  
用双螺杆挤出机反应性挤出的方法合成了低密度聚乙烯接枝马来酸镧(LDPE-g-MALa)离聚物。与其它方法相比,该法具有工艺简单,易于工业化生产的特点。我们将离聚物与PET,LDPE在双螺杆挤出机上熔融共混挤出,并用注射成型机制备标准样条,对共混物力学性能进行了测试,发现离聚物有显著的增韧效果,另外,通过IR,DSC,溶解性实验,分子量的测定等还考察了离聚物对PET/LDPE共混体系的结构影响。  相似文献   

2.
DBM-g-PE与PVC的相互作用研究EI   总被引:5,自引:1,他引:4  
采用固相接枝法制备了DBM-g-PE,用红外光谱分析证明了接枝物确实存在。PVC/CPE=100/5合金性能测定结果表明,添加5份接枝物的合金(A),缺口冲击强度、拉伸强度分别为18.2kJ/m2和53.0MPa;而添加5份PE的合金(B),其相应性能为5.1kJ/m2和33.8MPa。不加接枝物的合金(C),虽有高韧性,但拉伸强度却由53.0MPa降至50.2MPa。DSC、SEM的结果均表明,PE接枝DBM后与PVC的相互作用增强,与CPE协同作用能增韧、增强PVC,并探讨了其机理。  相似文献   

3.
PET/HDPE共混物的形态结构及力学性能的研究   总被引:9,自引:0,他引:9  
利用IR、SEM、DSC和力学测试等分析方法,研究了熔融接枝高密度聚乙烯(HDPE-g-MA)和界面改性剂(IM)对PET/HDPE共混物形态结构、界面偶联状况和力学性能的影响。结果在明,HDPE-g-MA改善了PET与HDPE的相容性,使HDPE较均匀地分散在PET基体中,但并未检测到PET/HDPE-g-MA界面有化学反应发生。界面改性剂的作用在于,一方面通过提高PET基体的粘度,并接近HDPE相的粘度而使分散相细化;另一方面通过与HDPE-g-MA和PET的偶联反应而增强了PET/HDPE-g-MA界面粘结,从而显著地提高了共混物的抗冲击性能。  相似文献   

4.
LDPE硅烷接枝及其交联副反应研究   总被引:1,自引:0,他引:1  
蒋涛  黄世强 《材料导报》1998,12(4):53-56
研究了以DCP(过氧化二异丙苯)为引发剂,在挤出过程中将不饱和硅烷(乙烯基-三甲氧基硅烷)接枝到LDPE分子链上时,挤出温度、DCP用量、硅烷用量等因素对接枝率及交联副反应的影响,采用红外光谱计算接枝率;通过凝胶含量测量对熔融接枝过程中的交联副反应进行跟踪测量,结果表明,在溶融接枝过程中,交联副反应是二种反应的加和,一种是DCP引发LDPE分子间的C-C交联,另一种是接枝后的大分子链上的-Si(O  相似文献   

5.
研究了EAA与端唑啉聚醚(活性聚醚)的偶联接枝反应,用IR及化学分析方法证实了流形接枝物EAA-g-PEO的生成;考察了不同用量和不同种类的活性聚醚所形成的梳形接枝物对LDPE表面电阻率的影响,实验证明该梳形接枝物是一种较好的持久性高分子抗静电剂.  相似文献   

6.
HPB-b-PMMA增容PVC/PE共混物球晶和结晶行为研究   总被引:2,自引:0,他引:2  
以小角激光散射(SALS)和广角X光衍射(WAXD)技术,测定了氢化聚丁二烯-聚甲基丙烯酸甲基嵌段共聚物(HPB-b-PMMA)增容的聚氯乙烯(PVC)和聚乙烯(PE)共混物的球晶形态和结晶度。从该共混物中PE的结晶状况得出,增容剂HPB-b-PMMAd在降低PE结晶能力、增加PE/PVC界面粘合并形成PVC和PE相间的部分相容性有着重要的作用。  相似文献   

7.
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   

8.
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   

9.
研究了丙烯酸作为接支单体,过氧化二异丙苯作为引发剂,与低密度聚乙类混合,在单螺杆挤出机中进行熔融接枝反应,测定了LDPE-g-AA的熔融旨数和表征接枝率的吸光比。结果表明,各因素对MI和R的影响程度是不同的,AA掺入量与MI有密切相关,而DCP加入量对MI影响程度较小。  相似文献   

10.
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   

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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