| Polyurethane foam is a kind of polymer materia ls, Because of its excellentproperties such as: Thermal insulation, mechanical, electrical, acoustic andchemical resistance. Coupled with its processing is very convenient, so it hasbeen applied more and more widely in many industries such as: refrigerator,freezer refrigeration transport, furniture manufacturing and other fields. But thePrevious foaming agent for the production of polyurethane are ozone depletingsubstances, from the point of view of sustainable development and environmentalprotection We must use a material which no pollution to the environment as afoaming agent to produce polyurethane foam. In this paper, we use low pressurecarbon dioxide as polyurethane foam, Not only can we meet the requirements ofenvironmental protection, but also we do not need to reform the polyurethaneequipment. So we can save money in a certain extent.According to relevant data, we independent design, development andassembly a set of equipment which use low pressure CO2as a foaming agent toproduce polyurethane, and we get the polyurethane foam which with differentcontent of carbon dioxide for experimenta l research,This is the most importantinnovation in this paper. The test focuses on research the changes of polyurethanefoam bubble structure which caused by the content of carbon dioxide ofpolyurethane foam.In this paper, molded foaming is emp loyed to prepare polyurethane foam.We get polyurethane foam under the conditions of maintaining the formulationand process conditions rema in unchanged, only change the content of the carbondioxide of polyurethane. The polyurethane products which use low pressurecarbon dioxide foamed has fewer pinhole and the bubble is more uniform. Byusing optical microscope we find that the size of the polyurethane bubble isincreased caused by increase CO2content.This paper introduces and describes the control equation of bubble growth,and we use the control equation studied the growth of bubble by numericalsimulation. The simulation results showed that with the increase of carboncontent, polyurethane foam radius increases gradually, but the radius gr owth rategradually decreases. Put forward the relationship between the radius and thecarbon dioxide content and time. Analys is of the causes of polyurethane compression strength increases with the increase of the bubble radius.because thebubble radius increases gradually with the increase of CO2content, while theincrease of bubble radius leads to compression performance improvement. Wecan get conclusion that the compression strength of polyurethane increases withthe increase of CO2content. |
