Study On Components Of Organosiloxanes

Organic-silicon compound is a new kind of industrial products with many breeds and excellent capability. They have been applied in textile, plastic, toiletry, printing ink, dope, medicament, metalworking, mechanism, etc. The variety of breeds, the complexity of ingredients, intense reactive of monomer adds difficulty to analysis of organic-silicon compound. There are problems in analysis of function groups and siloxanes of small content and polysiloxanes of complex structure. It is still a great task in the ascendant.1. Methylchlorosilanes are basic raw materials of organic-silicon industry. There are very much outgrowth during the production of methylchlorosilanes, for example, lowboiling compounds. In the lowboiling compouds of methylchlorosilanes, there are methylsilicane, low olefin, chloro alkane besides methylchlorosilanes. For reusing the lowboiling compounds and optimizing the synthetical technics, it is necessary to analyse the lowboiling compounds qualitatively and quantificationally. They cannot be separated well on gas chromatography, because their boiling point is very low and boling range is narrow. It needs new methods to solve this problem.Methyldichlorosilane and 2-methyl-2-butylene cannot be separated on one capillary column. However, methyldichlorosilane can be alcoholsed rapidly and thoroughly, but 2-methyl-2-butylene cannot. The ingredients of lowboiling compoud were analyzed by GC/MS before and after alcoholsis. Then the relative content of methyldichlorosilanes which cannot separate well with 2-methyl-2-butylene was determined with tetramethylsilanes as reference which can not be methanolized.2. Hydrosilicon oil is synthesized commonly by hydrolysis and equilibrium of organic hydrochlorosilanes and organic chlorosilanes, or organic polysiloxanes. The production consists of tow or three types of polymethylhydrosiloxanes, and every type consists of many homologs of different polymerization degree. Hereby, the ingredients in hydrosilicon oil are very complex. The molecule-ion in mass spectra of polymethylhydrosiloxanes gained from electron ionization (EI) is obvious commonly, except the cyclohydrosiloxanes of low molecular-weight. The major ions of all types of polymethylhydrosiloxanes are same and only the intensity of major ions has some difference. The difference becomes smaller with the molecular-weight increasing, so that they cannot be distinguished only by their mass spectras.However, The ingredients with semblable structure in polymethylhydrosiloxanes product exert some speciality in aspect of retention time of gas chromatography and distribution of content. The ingredients with low molecular weight and early retention time are analyzed by GC/MS and their structure is made sure. Then confirm the structure of ingredients with large molecular weight and late retention time with the speciality mentioned above. Then, they are analysed quantificationally by gas chromatography and their retention index is calculated. The results indicate that, sample "HDF" mainly contains dihydro-closed complete hydrosilicon oil(HMe₂SiO (MeHSiO) _nSiMe₂H), methyl-hydro complete hydrosilicon oil (HMe₂SiO (MeHSiO)_nSiMe₃) and cyclohydrosiloxanes( ( MeHSiO )_n); The sample "TSF" mainly contains cyclohydrosiloxanes and methyl-closed complete hydrosilicon oil (Me₃SiO (MeHSiO) _nSiMe₃), The sample "HDT" mainly contains methyl-hydro complete hydrosilicon oil, cyclohydrosiloxanes and methyl-closed complete hydrosilicon oil. 52, 40 and 52 ingredients in turn had been determined with accounting for 88.5%, 97.2% and 94.1% in turn.We also measured and calculated the retention index of some ingredients in complete hydrosilicon oil.3. It comes down to four types of complete hydrosilicon oil (methyl-closed complete hydrosilicon oil, dihydro-closed complete hydrosilicon oil, methyl-hydro complete hydrosilicon oil and cyclohydrosiloxanes). There are four ion series on all of their mass spectra, and the mantissa of m/z value is "5", "9", "3"and "7" in turn. Four ions can be organized into groups, and the numbers in each group increase 14 in turn, that is the weight of CH₂. In addition, the numbers in every group correspondingly increase 60 in turn, that is the weight of (MeHSiO). These are the MS character of four types of complete hydrosilicon oil in common. However, the abundance of corresponding ions in each group has some difference in their mass spectra. We summarize their difference in this thesis.4. The originality in this thesis:(1) Taking the tetramethylsilanes contained inherently in sample as reference, to calculate the content of bad-separated ingredients quantificationally, with considerating the changes between before and after alcoholsis. (2) Analysing the large molecular-weight ingredients in hydrosilicon oil qualitatively, based on the qualitative results of low molecular-weight ingredients with character of mass spectra anf retention behavior on chromatography.(3) Measuring and calculating the retention index of some ingredients in complete hydrosilicon oil for the first time.Anyway, the methods used in this thesis for the lowboiling compouds of methylchlorosilanes and hydrosilicon oil are valid. These methods can apply to analysis of other types of organic-silicon compound.