Experimental Research Of Substrate Works On Polymer Crystallization

Many well-known factors including cooling rate, stretching and shearing that affect the ratio of polymer's crystallization. In our research work we found some possible factors are also connected with polymer's crystallization such as the interface energy between the polymer melt and the substrate, the surface roughness and heat emission of the substrate. In our experiments a high density polyethylene (HDPE) was used through optical and rheological measurements. Primary task are as follows:1. Polymer material, application foreground and the main properties of HDPE, the effect of crystallization rate on properties of product, and the factors that affect crystallization rate of polymers, the basic theory and research methods of polymer's crystallization, and the concept and measuring method of interfacial tension were introduced.2. The experimental equipment was constructed, including Cell design, pedestal and bracket design, expounding choice of flowmeter, galvanothermy equipment design, design and principle of control circuit and so on.3. The conception of figure image, MATLAB image type,color model and the conversion of different color model were introduced. Then taking the image grayness change as a characteristic means of crystallization rate. The feasibility of this method was investigated by experiment. A conclusion was drawn from the experiment that at the same temperature, the fastest isothermal crystallization rate of HDPE is on the aluminum plate, and slowest is on the stainless steel plate for the three similar plates made of aluminum,brass, stainless steel. The possible factor that affects the crystallization rate is the interface character between HDPE and substrate, and interfacial tension was measured through experiment.4. Taking the change of luminous flux through HDPE melt as another characteristic means when it was in the progress of static isothermal crystallization. The basic producing condition and constructure of laser implement especialy PR-102 aptitude multicenter photometer in experiment were introduced. The same crystallization order...