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1.
The phase behavior of several polycarbonate homopolymers and copolymers blended with PVC and chlorinated PVCs (CPVCs) has been investigated. Tetrachlorobisphenol-A polycarbonate (TCPC) is miscible in all proportions with PVC and CPVCs containing up to70.2 wt% chlorine. CPVCs having chlorine contents greater than 70.2% (by weight) are immiscible with TCPC. Tetrabromobisphenol-A polycarbonate (TBPC) exhibits phase mixing with PVC and CPVCs; however, the high Tg of this polycarbonate (260°C) prevents adequate investigation of equilibrium phase behavior. Bisphenol-A polycarbonate (BPC), tetramethylbisphenol-A polycarbonate (TMPC), and hexafluorobisphenol-A polycarbonate (HFPC) form two-phase mixtures with the vinyl polymers. Microstructural differences in the CPVCs due to chlorination method (solution chlorination vs. slurry chlorination) have no effect on the miscibility results. Miscibility was observed in several copolycarbonate/CPVC blends and was found to be dependent on copolymer composition. Using a binary interaction, mean-field theory, segmental interaction parameters were estimated for repeat unit interactions. Based on the estimated interaction parameters, miscibility in these blends is primarily the result of intramolecular repulsive effects, rather than strong intermolecular attractive forces.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

2.
Polyvinyl chloride) obtained by intermittent polymerization in suspension with temperature programming, has been characterized from the point of view of morphological properties and of thermal stability. The data have been compared with the values of the morphological characteristics and thermal stability for the PVC samples obtained under identical polymerization conditions, but at constant temperature. The polyvinyl chloride) obtained by polymerization with temperature programming has the same properties as the polyvinyl chloride) obtained by simple polymerization at constant temperature, with an identical average molecular weight. However, the former polymer shows improved thermal stability, as well as a decrease in the volumetric properties.  相似文献   

3.
姜治伟  薛俭  杜中辉  唐涛  刘文彬 《应用化学》2014,31(11):1248-1254
采用异氰酸酯和环氧树脂作为交联剂,偶氮二异丁腈(AIBN)和偶氮二甲酰胺(AC)作为发泡剂制备了交联聚氯乙烯泡沫材料。 通过扫描电子显微镜分析了两种发泡剂的粒径、比例以及用量对泡孔结构的影响。 结果表明,AIBN的粒径对泡沫的泡孔结构影响不大,但其用量增加导致泡沫密度减小;AC的粒径对泡孔结构产生一定的影响,最优的粒径范围为8~20 μm,并且随着用量增加,泡孔尺寸变小,但对密度影响不大。 采用DSC研究了AIBN和AC在预混料中的分解情况,提出了两种发泡剂影响泡沫的泡孔结构的机理。 对泡沫材料力学性能的分析表明,泡沫的强度随密度的增加而增加,剪切变形则在60~80 kg/m3密度范围内出现最大值。  相似文献   

4.
火焰原子吸收光谱法及比浊法测定聚氯乙烯中氯   总被引:1,自引:0,他引:1  
以无水碳酸钠为灰化固定剂,于瓷坩埚中加热将试样灰化,于高温炉中在700℃燃烧2 h,用水溶出残渣,分取部分试液用火焰原子吸收光谱法(FAAS)或浊度法测定其中氯离子.加入过量银以沉淀样品溶液中的氯离子,用FAAS法测定银以间接测定氯,或通过测定氯化银悬浮体的表观吸光度而测定氯,建立了FAAS法及比浊法测定聚氯乙烯中氯含量的方法.线性范围:FAAS法为0~140μmol·L-1,比浊法为0.4~4.8 mg·L-1.测定结果的相对标准偏差≤1.9%,加标回收率95.0%~102.5%.两种方法测定结果的相对误差小于士1.1%.  相似文献   

5.
The thermal degradation of a sort of polyvinyl chloride was investigated. Complex processes for polyvinyl chloride degradation were evidenced. The kinetic analysis of dehydrochlorination and of subsequent processes was carried out. A change of mechanism was detected when dehydrochlorination goes to completion. The values of non-isothermal kinetic parameters determined by various methods are in a satisfactory agreement. The obtained results allowed some clarifications concerning the thermal degradation steps. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

6.
The feasibility was studied of plasticization of rigid polyvinyl chloride with a reclaimed polyvinyl chloride-polyurethane mixture yielded by thermomechanochemical degradation of wastes of polyurethane foam coated with a polyvinyl chloride film. The molecular-weight distribution of the polyurethane component, temperatures of phase transitions, and physicomechanical properties of the polymer systems were studied as influenced by the preparation temperature of the reclaim.  相似文献   

7.
李于善 《分析化学》2001,29(4):491-491
1  引    言苋菜红(AMR)是合成食用色素,由对氨基萘磺酸重氮化后与2-萘酚-3,6-二磺酸偶合,经盐析精制而得,有一定毒性,现广泛应用于食品和医药,我国食品添加剂使用(GB2760-1996)规定其最大用量为50 μg/g。常见的苋菜红的检测方法有HPLC法、示波极谱法、分光光度法、薄层色谱法和三氯化钛滴定法(标准法)。曾有文献报道以电位型化学传感器测定柠檬黄、胭脂红等合成食用色素,尚未见有以BN20C6为载体的PVC膜AMR化学传感器的报道。本文首次以新合成的联萘-20-冠-6(BN2…  相似文献   

8.
刘理中  肖立新 《合成化学》1995,3(2):169-172
合成了两种聚氯乙烯负载希夫碱,即乙二胺缩水杨醛类(PEDS)和乙二胺缩呋喃甲醛类(PEDF).并对其结构进行了红外表征。  相似文献   

9.
Russian Journal of Applied Chemistry - Coagulation of natural rubber and polyvinyl chloride latices with poly(diallyldimethylammonium chloride) was studied. The influence exerted on coagulation of...  相似文献   

10.
聚氯乙烯三氯化铁树脂的合成与应用   总被引:3,自引:0,他引:3  
介绍了聚氯乙烯三氯化铁树脂的制备方法和作为催化剂在酯化作用、酯交换作用、缩醛(酮)化作用及分子重排等方面的应用,说明了反应历程。  相似文献   

11.
聚氯乙烯—多乙烯多胺树脂的合成与表征   总被引:15,自引:0,他引:15  
俞善信  徐满才 《合成化学》1997,5(4):416-419
利用聚氯乙烯与多乙烯多胺合成了聚氯乙烯-多乙烯多胺树脂,测定了交换量,并根据元素分析和红外光谱对其结构进行了初步表征。  相似文献   

12.
Polymer alloying is acquiring ever increasing significance for the modification of polymeric materials. Polymer alloys are defined by their phase character, which in turn is determined by the mutual compatibility or incompatibility of the components. Suitable techniques for the analysis of the phase character include, inter alia, dynamic-mechanical methods, according to which a polymer alloy may be considered in a simplified manner as single-phase when only one glass transition is observed, even if it extends over a broader temperature range than in the case of the pure components. Aliphatic (polyester)-polycarbonates and tetramethylbisphenol-A polycarbonate are new, PVC-compatible, polymer modifiers. The (polyester)-polycarbonates (from adipic acid, hexane-1,6-diol, neopentanediol, and diphenyl carbonate) yield with PVC single-phase alloys that at temperatures above the glass transitions of the mixture display the characteristics of soft PVC and that are tough far below this temperature. The special high-temperature properties of the resin-like tetramethylbisphenol-A polycarbonate permits the preparation of alloys with increased dimensional stability under heat (higher deflection temperatures under load).  相似文献   

13.
聚氯乙烯膜诺氟沙星选择电极的研制与应用   总被引:4,自引:0,他引:4  
李东辉  汪敏 《分析化学》1996,24(8):931-933
  相似文献   

14.
聚氯乙烯膜苯海拉明选择电极的研制与应用   总被引:8,自引:0,他引:8  
报道了一种以苯海拉明碘化物与碘化铋形成的分子缔合物为电活性物的新型PVC膜苯海拉明选择电极。电极的线性响应范围为 1 0× 10 -1~ 2 .6× 10 -5mol/L ;级差为 4 8mV/pC ;检出限为 1 9× 10 -5mol/L。该电极响应迅速 ,重现性好 ,用此电极以校准曲线法对片剂中的苯海拉明进行了测定 ,此法简便 ,结果与药典法相符  相似文献   

15.
聚氯乙烯膜诺氟沙星选择电极的研制与应用   总被引:2,自引:0,他引:2  
1 引  言诺氟沙星为氟喹酮衍生物 ,是一种杀菌剂。临床上用于消化系统、泌尿系统疾病的治疗。它的测定方法一般采用药典法、分光光度法、也有应用高效液相色谱法、离子对比色法、沉淀回滴法、极谱法、伏安法和离子选择电极法等。本文离子选择电极法以诺氟沙星与碘分子缔合物为电活性物的新型PVC膜选择电极 ,用此电极对诺氟沙星药片的含量进行了测定。此法简便 ,结果与药典法相符。2 实验部分2 .1 仪器与试剂 PXJ 1B数字式离子计 (江苏电分析仪器厂 ) ;79型磁力搅拌器 (国华仪器厂 )。诺氟沙星 (锦州生化制药厂 )溶液以 1 %HA…  相似文献   

16.
PVC膜修饰粉末微电极的研制及应用   总被引:8,自引:0,他引:8  
聚合物具有催化、导电和选择分离等功能,将其与电极合为一体作为新的电极材料,可为改善固体电极的灵敏度、选择性和重现性提供一种新的手段[1,2].我们用流延法[3]制得PVC选择性渗透膜,覆盖于粉末微电极表面,制成了PVC膜修饰粉末微电极.该电极性能稳定...  相似文献   

17.
聚氯乙烯膜曲马多选择电极的研制与应用   总被引:3,自引:0,他引:3  
报道一种以曲马多与四苯硼的缔合物为电活性物的新型PVC膜曲马多选择电极,电极的Nernst响应范围为1.0×10~(-2)~2.1×10~(-5)mol/L;斜率为57mV/pC;检测限为7.2×10~(-6)mol/L。此电极响应迅速,重视性好,用此电极以标准曲线法对药物中的曲马多进行了测定,此法简便,结果与紫外分光光度法相符。  相似文献   

18.
医用聚氯乙烯膜的等离子体表面改性   总被引:4,自引:0,他引:4  
用两种不同气氛的辉光放电等离子体工艺对医用软质聚氯乙烯(PVC)膜进行了表面改性研究。结果表明,聚合性气氛的等离子体改性效果明显优于非聚合性气氛。平整致密的聚合膜对PVC增塑剂——邻苯二甲酸二辛酯的迁移和扩散起了阻挡作用,也使膜表面亲水性和表面张力极性成份增大,液固相界面张力减小,生物相容性得以改善。  相似文献   

19.
Abstract

The synthesis and characterization of new vinyl chloride-p-acryloyloxyazobenzene copolymers are reported. Kinetics of photoinduced trans-cis and thermal cis-trans isomerization of azo pendant groups in copolymer have also been investigated, and the kinetic parameters were evaluated. An azo acrylate model compound was used for comparison.  相似文献   

20.
聚氯乙烯膜修饰碳微电极的研制及应用   总被引:7,自引:0,他引:7  
但德忠  陈文  龚峰景  徐峰  王正猛 《分析化学》2000,28(9):1150-1154
采用浸涂流延法制得PVC膜修饰碳微电极,用K3Fe(CN)6的循环伏安图考察了电极的电化学性能,并用此电极建立了环境水样中痕量汞的阳极溶出伏安法测定。在0.06mol/L KSCN+0.01mol/LKCl介质中,富集电位-0.80V,搅拌富集时间300s,扫描电压范围-0.20~0.40V,扫描速率314mV/s,咄峰电流与Hg^2+浓度在0.01~2.0mg/L的范围内有良好的线性关系,本电极  相似文献   

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