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1.
用DPMS、TG、DTA等方面研究了聚β-羟基丁酸酯(PHB)及其共聚物P(HB-co-HV)的热分解行为和某些结构性质,提供我至7个链节重复单元的裂解碎片,可较好地反应共聚物的组成和分布,结果表明:聚β-羟基烷酸酯的热分解具有较高的的选择性,通过β-H转移反应形成由羧基和烯烃结尾的齐聚物。  相似文献   

2.
用高分辨裂解气相色谱 质谱(HRPyGC MS)研究了聚亚苯基苯并二噻唑、聚亚苯基苯并二唑的热分解行为,鉴定了相应裂解产物的组成、分布及其与高分子结构的关系,并用热重法(TG)测定了它们的热分解反应动力学参数,提出了其热分解反应机理  相似文献   

3.
用DPMS、TG、DTA等方法研究了聚β-羟基丁酸酯(PHB)及其共聚物P(HB-co-HV)的热分解行为和某些结构性质.能提供多至7个链节重复单元的裂解碎片.可较好地反应共聚物的组成和分布.结果表明:聚β-羟基烷酸酯的热分解具有较高的选择性,通过β-H转移反应形成由羧基和烯烃结尾的齐聚物.齐聚物准分子离子可进一步脱去一分子水.  相似文献   

4.
聚亚苯基苯并二噻唑与聚亚苯基苯产二E唑的热分解   总被引:4,自引:0,他引:4  
用高分辨裂解气相色谱-质谱(HR PyGC-MS)研究了聚亚苯基苯并二噻唑、聚亚苯基苯并二E唑的热分解行为,鉴定了相应裂解产物的组成、分布及其与高分子结构的关系,并用热重法(TG)测定了它们热分解反应动力学参数,提出了其热分解反应机理。  相似文献   

5.
用TG-DTG-DSC热分析技术研究了三(O,O′-二异丙基二硫代磷酸酯)合钴(Ⅲ)、双(O,O′-二乙基二硫代磷酸酯)合镍(Ⅱ)及其后者与吡啶或4-甲基吡啶加合物在氮气气氛中的热行为;用传统的微商法(A-B-S)和积分法(C-R法)以及分别由Malek、Dollim ore 提出的两种新型的热分析动力学方法协同处理TG 数据,获得了四种配合物的热分解反应动力学参数E和A,确定了反应机理。对它们的热行为和分子结构之间的关系进行了讨论;并试就本文所用的几种数据处理方法作了比较。  相似文献   

6.
稀土硝酸盐甘氨酸固体配合物热化学研究   总被引:2,自引:0,他引:2  
稀土硝酸盐甘氨酸固体配合物热化学研究刘宗怀,宋迪生,刘翊纶(宝鸡文理学院化学化工系,宝鸡721007)(西北大学化学系,西安710069)本文在稀土硝酸盐甘氨酸固体配合物合成、表征工作基础上[1],应用TG-DTG、DSC分析讨论了配合物热分解过程,...  相似文献   

7.
聚氨酯醇酸的裂解气相色谱-质谱研究   总被引:5,自引:1,他引:4  
人工合成聚氨酯醇酸,用裂解气相色谱-质谱(PGC-MS)法详细研究其热裂解产物的化学组成,探索其热裂解机理。裂解的主要产物为合成所用的单体甲苯二异氰酸酯(TDI)、邻苯二甲酸酐及油脂相应的脂肪酸。  相似文献   

8.
采用国产SC-7型色谱仪及JP-01型居里点裂解器、Nicolet170SX红外光谱仪及接口组成的裂解气相色谱-傅里叶变换红外光谱(PGC/FTIR)分析仪、HP-17型大口径毛细管色谱柱,分析了两个复杂组成的聚合物样品。从主要裂解碎片峰的定性结果及形成机理出发,逐步推出了原样品的组成和结构。常规红外光谱分析方法被用来作为对比,但它获得的信息有限,无法得到能与PWBCGC/FTIR分析结果相媲美的结论,充分显示了PWBCGC/FTIR用于聚合物分析的优越性。  相似文献   

9.
Zn(C9H6O5N2)·2H2O配合物热分解非等温动力学的研究   总被引:2,自引:0,他引:2  
石凤  王大庆 《结构化学》1999,18(6):443-447
合成了Zn(C9H6O5N2)·2H2O,用元素分析、红外光谱、摩尔电导对该配合物进行了表征。并用热重(TG)对其热分解机理进行了研究,推断出了该配合物第三步热分解的非等温动力学方程为: dα/dt= Ae- E/RT(1- α)。  相似文献   

10.
采用国产SC-7型色谱以及JP-01型居里点裂解器,Nicolet170SX红外光谱仪及接口组成的裂解色相色谱-傅里叶变换红外光谱(PGC/FTIR)分析仪,HP-17型大口径毛细管色谱柱,分析了两个复杂组成的聚合物样品。从主要裂解碎片峰的定性结果及形成机理出发,逐步推出了原样品的组成和结构,常规红外光谱分析方法被用来作为对比,但它获得的信息有限,无法得到能与PWBCGC/FTIR分析结果和媲美的  相似文献   

11.
The simultaneously working combination of thermal analysis and mass spectrometry (TA/MS) is a very useful method for studying the degradation process of polymeric materials during thermal treatment [1–7]. Beside the thermal effects, as recorded from thermogravimetry (TG) or differential thermal analysis (DTA) the evolved degradation products can be determined and identified by the on - line coupled mass spectrometer. Additional their temperature depending abundance can be registrated. Combustion of polymers in horizontal (BIS) or vertical (VCI) furnaces and subsequent off line high resolution GC/MS analysis of pyrolysis products is suitable for the simulation of burning processes  相似文献   

12.
The techniques of differential thermal analysis (DTA), thermogravimetry (TG), large scale pyrolysis (LSP) and hot-stage microscopy (HSM) have been used to determine the pyrolysis behaviour of three binary polymer systems: wool/Terylene, wool/Courtelle and Terylene/Courtelle. Pyrolysis was carried out in a flowing nitrogen atmosphere at a heating rate of approximately 10°C min?1.Evidence from DTA and TG indicates that the thermal stability of the polyester fibre Terylene is reduced when pyrolysed in the presence of either wool or Courtelle. It is considered that this reduction in thermal stability is the result of chemical interactions between Terylene and degradation products arising from the breakdown of the second polymer present. Unexpectedly high residual yields (at 1213 K) have been observed from LSP experiments on the wool/Courtelle and Terylene/Courtelle systems.HSM observations for these two systems indicate the formation of a coating of the fusing polymer around the non-fusing polymer during pyrolysis. TG studies indicate that this coating of fused polymer may be effective in retaining volatile degradation products from the non-fusing polymer within the solid residue. The eventual chemical bonding of these degradation products into the solid residue thus accounts for the unexpectedly high yields of solid residue observed by LSP.  相似文献   

13.
The thermal degradation behaviors of Kevlar 49, Kevlar 129 (Poly(p-phenylene terephthamide), Nomex (polyisophthaloyl metaphenylene diamine), and PBO(poly(p-phenylene benzobisoxazole)) fibers were measured by TG/FTIR and Py-GC/MS. The characteristic temperatures of the fibers in air were obtained by TG. It indicated that the initial degradation temperature of the PBO is the highest. The initial degradation temperature of Nomex fiber is the lowest, but the end decomposition temperature of Nomex is the highest. The gases released by the pyrolysis in air were mainly CO2, CO, H2O, NO, and HCN, also containing a small amount of NH3, and the absorption peaks of CO2 were the strongest. The results of Py-GC/MS showed that CO2 and benzene were the most pyrolysis fragment. With the change of pyrolysis temperature, the chromatogram and mass spectra results take a large variety. The pyrolysates can help us to study the pyrolysis process of high performance fibers.  相似文献   

14.
Thermogravimetric analysis (TG) provides information regarding mass changes in the sample resulting from heat treatment under controlled environment. However, it does not provide any chemical information regarding the gases evolved during the thermal degradation. Using FT-IR spectrometry in combination with TG, it is often possible to identify the evolved gases, and also monitor their evolution profiles during thermal degradation. In this study, we present the TG/FT-IR combined analysis of incineration and pyrolysis of some common plastics such as high density polyethylene (HDPE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS). This study demonstrates the utility of such combined analysis in providing useful information regarding the use of thermal treatment for recycling or incineration.  相似文献   

15.
张燕红  黄洪  夏正斌  陈焕钦 《色谱》2008,26(4):519-522
采用高分辨裂解气相色谱-质谱法(PyGC-MS)分析了FR-4型印刷电路板粉末样品的裂解产物。在氦气氛围中,分别在350,450,550,650和750 ℃下对印刷电路板粉末样品进行热裂解,并通过毛细管气相色谱-质谱对裂解产物进行分析,研究了不同裂解温度下裂解产物分布以及主要裂解产物的产率与裂解温度的关系,根据热分解产物的组成,探讨了热分解反应机理。  相似文献   

16.
Two components of electronic wastes (sample A – a mixture of three types of printed circuit boards, sample B – a mixture of electronic junctions with metal wires) were investigated using thermogravimetric analysis (TG). Thermogravimetric and derivative thermogravimetric data (TG and DTG) give information on the thermal stability of A and B samples and allows finding the correct conditions for their degradation using pyrolysis in an experimental system, built on the laboratory scale for utilization of hazardous wastes. X-ray fluorescence measurements prove that brominated flame retardant is present in sample A, whilst chlorinated flame retardant is a probable component of sample B. Preliminary liquid chromatography of oil products obtained as a result of thermal waste degradation shows that the hydrocarbons released during pyrolysis could be used as a fuel.  相似文献   

17.
In this paper, thermogravimetry, TG, and pyrolysis are used for the thermochemical evaluation of the common reed (Pragmites australis) as a candidate biomass feedstock. The TG analysis indicated that the material loses 4% of its weight below 150 °C through dehydration. The main decomposition reaction occurs between 200 and 390 °C. The rate of weight loss, represented by the derivative thermogravimetric, DTG, signal indicated a multi-step reaction. Kinetic analysis helped in the resolution of the temperature ranges of the overlapping steps. The first step corresponds to the degradation of the hemi-cellulosic fraction and the second to the cellulosic fraction degradation. The TG and DTG signals of reed samples treated with increasing concentration of potassium carbonate (0.6–10 wt%) indicated a catalytic effect of the salt on reed decomposition. The temperature of maximum weight loss rate, DTGmax, exponentially decreased with increasing catalyst content, whilst the initial temperature of the decomposition decreased linearly. The pyrolysis studies were carried out in a Pyrex vertical reactor with sintered glass disc to hold the sample and to aid the fluidization with the nitrogen stream flowing upwards. The reactor was connected to a cyclone and condenser and a gas sampling device. Tar and char are collected and weighed. The gas chromatographic analysis of the evolved gases demonstrated the effect of pyrolysis temperature (400, 450, and 500 °C) on their composition. The temperature increase favors the yields of hydrocarbons, carbon monoxide and hydrogen at the expense of methanol and carbon dioxide. Similarly, reed samples treated with K2CO3 at 10 wt% were pyrolyzed and analyzed. Comparisons for the various parameters (yields, gas composition and carbon–hydrogen recovery) between the untreated and catalyzed reed conversion were also made.  相似文献   

18.
The thermal degradation of synthetic waterborne polyurethane (PU) based on toluenediisocyanate (TDI) was investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetry (TG). The degradation profiles of cast films obtained from dispersions were evaluated. More than 20 characteristic volatile pyrolyzates reflecting the structure and pyrolysis mechanisms of the polymer have been identified by on-line MS. The synthesized products of polyurethane were pyrolyzed at 350, 450, 550, 650 and 750 °C respectively, and the analysis results revealed that the pyrolyzates distribution of the polyurethane depends strongly on the pyrolysis temperature. The aqueous polyurethane thermogravimetric measurements were used to study the kinetics of thermal degradation.  相似文献   

19.
The thermal degradation of N,N′-bis(2 hydroxyethyl) linseed amide (BHLA) was investigated by thermogravimetric analysis coupled with Fourier transform infrared spectroscopy and mass spectroscopy (TG–FTIR–MS). Thermogravimetric analysis revealed that the thermal degradation process can be subdivided into three stages: sample drying (<200 °C), main decomposition (200–500 °C), and further cracking (>500 °C) of the polymer. The compound reached almost 800 °C during pyrolysis and combustion. The activation energy at the second step during combustion was slightly higher than that of pyrolysis emissions of carbon dioxide, aliphatic hydrocarbons, carbon monoxide, and hydrogen cyanide, and other gases during combustion and pyrolysis were detected by FTIR and MS spectra. It was observed that the intensities of CO2, CO, HCN, and H2O were very high when compared with their intensities during pyrolysis, and this was attributed to the oxidation of the decomposition product.  相似文献   

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