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11.
Chunxia Zhao Zhe Sun Bailing Liu Gang Peng 《Journal of Macromolecular Science: Physics》2013,52(10):1453-1464
Gemin-surfactant modified montmorillonite (G-MMT) was successfully prepared by an ion exchange reaction and characterized via Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The P(BA-VAc)/G-MMT emulsion was prepared via an in-situ polymerization method using potassium persulfate (K2S2O8, KPS) as an initiator. Ammonium polyphosphate (APP) was introduced for obtaining P(BA-VAc)/APP/G-MMT flame-retardant latex with a constant total content of 15 wt% of APP and G-MMT in P(BA-VAc). The flame retardancy and thermal behavior of the latex films were investigated by limiting oxygen index (LOI), vertical burning test (UL-94) and thermal gravimetric analysis (TG/DTA). Compared with the P(BA-VAc)/APP composite, the LOI value of P(BA-VAc)/APP/G-MMT containing 0.5 wt% G-MMT at the same total additive loading increased to 29.1 from 20.0 and its UL-94 increased from no rating to V-0. Thermal gravimetric (TG) data showed that the amount of residues increased significantly with the loading of G-MMT. In addition, the LOI values increased with the increase in char residues. The morphology and microstructure of the residues generated during LOI testing were investigated by scanning electron microscopy (SEM). The outer surfaces of P(BA-VAc)/APP/G-MMT charred layers were more continuous and compact than those of P(BA-VAc)/APP. 相似文献
12.
Carbon black (N234) and silica (Vulksail N) with a silane coupling agent Si-69 were chosen as reinforcing fillers in butyl rubber (IIR). The rheological behavior of the IIR compounds and the dynamic mechanical properties of IIR vulcanizates were investigated with a rubber processing analyzer and dynamic mechanical analysis (DMA) to examine the filler dispersion in the rubber matrix and the interaction between filler and matrix. The data indicated that the N234 filled IIR compounds had more filler networks than those filled with silica. Filler networks first appeared at 30 phr N234 and 45 phr silica with silane coupling agent Si-69. The interaction between N234 and IIR was far stronger than that between silica and IIR. However, the silica Vulksail N filled IIR had better wet-grip and lower rolling resistance compared to the carbon black-filled IIR should IIR be chosen as a substitute of styrene-butadiene rubber (SBR) in tire tread. The reinforcing factor, R, R (related to the difference in tan d peak height at Tg for the filled and nonfilled rubbers), also demonstrated that the N234-IIR interaction was stronger than for the silica. IIR with 30 phr N234 exhibited the largest tensile strength, 20.1 MPa, for those vulcanizates examined. The tensile and tear strengths of N234 filled IIR were higher than those of IIR with similar amounts of silica. Thus, it was concluded that N234 is a more active reinforcing filler in IIR than silica (Vulksail N) even with a silane coupling agent (Si-69). 相似文献
13.
黄原酯棉分离富集和石英缝管技术的FAAS测定环境水中痕量铅 总被引:1,自引:0,他引:1
本文研究了黄原酯棉富集铅的条件,探讨了应用石英缝管技术测定铅的方法。实验表明pH=7左右时,黄原酯棉能够定量地富集水中痕量铅,以1%HNO3、水浴20min即可定量解脱。应用石英缝管技术可比常规火焰测定铅的灵敏度提高3.3倍。本方法可应用于野外富集。 相似文献
14.
对甲苯磺酸催化合成乙酸正丁酯 总被引:8,自引:0,他引:8
用对甲苯磺酸作冰乙酸和正丁醇的酯化催化剂,成功地合成了乙酸正丁酯,考察了影响反应的因素,探讨并找到了较好的反应条件:乙酸l00mmol,n(冰乙酸):n(正丁醇):n(催化剂)=1:3:0.006,反应时间1.5h,不另加带水剂,产率达99.14%。 相似文献
15.
The rate of the Wolff-Kishner reaction of benzophenone hydrazone in butyl carbitol increases as the cation of the alkoxide base is varied in the order K>Na>Li>Mg. The replacement of butyl carbitol by 1-decanol also accelerates the reaction, and an additional increase is caused by the presence of crown ether. On the basis of changes in the activation parameters, it is concluded that the reactivity of the hydrazone anion increases as the contact ion pair becomes more fully solvated and dissociated. 相似文献
16.
17.
Contributions to the Chemistry of Phosphorus. 243 On the Oxocyclotetraphosphanes (PBut)4O1–4 Under suitable conditions, the reaction of tetra‐tert‐butylcyclotetraphosphane, (PBut)4, with dry atmospheric oxygen gives rise to the corresponding monoxide (PBut)4O ( 1 ) which has been isolated by column chromatography. The reaction with hydrogen peroxide furnishes a mixture of oxocyclotetraphosphanes (PBut)4O1–4 consisting of two constitutionally isomeric dioxides (PBut)4O2 ( 2 a , 2 b ), the trioxide (PBut)4O3 ( 3 ), and the tetraoxide (PBut)4O4 ( 4 ), in addition to 1 . According to the 31P NMR parameters the oxygen atoms are exclusively exocyclically bonded to the phosphorus four‐membered ring. Which of the P atoms are present as λ5‐phosphorus follows from the different low‐field shifts of the individual P nuclei compared with the starting compound. Accordingly, 1 is 1,2,3,4‐Tetra‐tert‐butyl‐1‐oxocyclotetraphosphane, 2 a and 2 b are 1,2,3,4‐Tetra‐tert‐butyl‐1,2‐dioxo‐ and ‐1,3‐dioxocyclotetraphosphane, respectively, 3 is 1,2,3,4‐Tetra‐tert‐butyl‐1,2,3‐trioxocyclotetraphosphane, and 4 is 1,2,3,4‐Tetra‐tert‐butyl‐1,2,3,4‐tetraoxocyclotetraphosphane. When the oxidation reaction proceeds a fission of the P4 ring takes place. 相似文献
18.
Yingwu Luo F. Joseph Schork 《Journal of polymer science. Part A, Polymer chemistry》2001,39(16):2696-2709
The polymerization kinetics of butyl acrylate/[2‐(methacryloyoxy)ethyl]trimethyl ammonium chloride (BA/MAETAC) macroemulsion and miniemulsion copolymerizations was investigated with cumene hydroperoxide/tetraethylenepentamine as a redox initiator system. The postulate of an interfacial copolymerization with the two‐component redox initiator system (one hydrophobic and the other hydrophilic) was confirmed. Adding MAETAC had a complex effect on the polymerization kinetics of BA. The influence was ascribed to variations in the nucleation mechanism, which were dependent on the level of MAETAC, and the polymerization method (macroemulsion vs miniemulsion). It was proposed that at the beginning of a macroemulsion copolymerization with high MAETAC composition the micellar copolymerization occurred, which controlled the nucleation process. The hydration properties of the latex were used to characterize the copolymer composition. The composition of the copolymer from the interfacial polymerization was very heterogeneous. The copolymer composition was lower in BA when there was an increase in BA conversion or the particle size. Adding salt increased the MAETAC content and decreased the BA content in the copolymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2696–2709, 2001 相似文献
19.
Contributions to the Chemistry of Phosphorus. 244. The First Oxatetraphospholane, (PBut)4O Under suitable conditions, the reaction ot tri‐tertbutylcyclotriphosphane, (PBut)3, with di‐tert‐butylperoxide gives rise to a mixture of 2,3,4,5‐tetra‐tert‐butyl‐1,2,3,4,5‐oxatetraphospholane, (PBut)4O ( 1 ), and 1,2‐di‐tert‐butyl‐1,2‐di‐tert‐butoxidiphosphane, [But(ButO)P]2 ( 2 ). Both compounds have been isolated in the pure state. The oxatetraphospholane 1 is a constitutional isomer of 1,2,3,4‐Tetra‐tert‐butyl‐1‐oxocyclotetraphosphane, which has been reported recently [1]. The corresponding reaction of tetra‐tert‐butylcyclotetraphosphane furnishes only small amounts of 1 because of the kinetic stability of (PBut)4. The diphosphane 2 is presumably a secondary product of primarily formed oxocyclotetraphosphanes (PBut)4O1–4. The NMR parameters of 1 and 2 are reported and discussed. 相似文献
20.
SBS与甲基丙烯酸丁酯本体接枝反应的研究 总被引:1,自引:0,他引:1
本文研究了以过氧化苯甲酰(BPO)为引发剂,甲基丙烯酸丁酯(BMA)既作溶剂又作为单体与苯乙烯-丁二烯嵌段共聚物(SBS)进行接枝共聚反应。用红外光谱、核磁共振谱及透射电镜表征了接枝共聚物(SBS-g-BMA)的组成及结构,讨论了时间、温度及SBS和BPO的用量对接枝的影响。 相似文献