|
PET polyester because of its good performance , widely used in different fields such as fibers, packaging film and plastic instead of aluminum, glass, ceramics , paper , wood , steel , and other synthetic materials . The polyester polycondensation stage commonly used in the industrial production of antimony catalyst , the potential harm to the environment and human health . The titanium-based catalyst is considered to be the most promising alternatives , but hard to regulate the activity of the homogeneous organic titanium compound , supported titanium-based rather than a homogeneous dispersion of the catalyst in the reaction system of hyperviscosity not effectively solve . In this paper, a new nanoscale fabrication techniques in the synthesis of a variety of highly dispersed titanium catalyst under different preparation conditions , TEM, EDAX analysis means were used to characterize the structure and character of the catalyst . In the catalytic preparation of PET study , the system examines the carrier characteristics, the titanium content, dispersibility , and the reaction time , temperature , degree of vacuum , etc. , discussed the preparation conditions of the catalyst structure , and thus its catalytic characteristics law , and explore the catalyst improved methods. Papers get the following conclusions . 1) catalyst system of this mass transfer is more difficult had good activity , its product intrinsic viscosity is close to the industrial fiber grade products , the largest group reached 0.8 dL / g . Highly dispersed catalyst adsorbed phase reaction technology to prepare a good application prospects . 2 ) The two carriers have different catalytic properties . Hydrophilic titanium catalyst with higher activity , can get the higher viscosity of the product , but its product hue is more difficult to control . Hydrophobic titanium catalyst product hue is better, but the viscosity of the resulting product to be lower than the hydrophilic . 3) under the same reaction conditions , the the catalyst titanium content and dispersibility affect the catalytic performance of two main factors . The titanium content increases make the product viscosity rise , dispersion will impact 4 ) vacuum can impose constraints on the catalyst performance products hue . If the degree of vacuum is too low , and the product is not only a low intrinsic viscosity , and its hue is also poor .
|