中文摘要：

通过高温高压磁悬浮天平（MSB）测定表观溶解度、高温高压视窗釜进行溶胀度校正的方法研究了CO2在PET熔体中的溶解度,考察了温度、压力对改性前后PET在CO2环境中的溶胀度和CO2溶解度的影响。结果表明,PET在CO2环境中的溶胀度和CO2溶解度均随温度的增加而减小,随压力增加而增加,但高压下溶胀度的增加趋势减缓并趋于某定值;与常规线性PET相比,改性PET具有较小的溶胀度和溶解度。在250～280℃,4～6MPa下,CO2在PET熔体中的溶解度具有10-2 g CO2.（g PET melt）-1的量级。1～6MPa下CO2在PET熔体中的溶解行为符合亨利定律,利用最小二乘法拟合得到了CO2在PET熔体中的溶解热。

英文摘要：

The solubility of CO2 in poly（ethylene terephthalate）（PET） was studied using magnetic suspension balance（MSB） combined with high-temperature high-pressure view cell.The former gives apparent solubility and the latter presents swelling volume through direct observation in the presence of CO2,which is necessary to correct the gas buoyancy acting on PET melts in the MSB measurement.The effects of temperature and pressure on the swelling ratio and CO2 solubility in traditional and modified PET melt were analyzed.The results show that both swelling ratio of PET and solubility of CO2 decrease as temperature increases and increase with pressure.However,the swelling ratio increases slowly and approaches a plateau region under higher pressure.Compared with traditional linear PET,the modified PET displays lower swelling ratio and solubility.Solubility of CO2 in PET melt is in an order of magnitude of 10-2 g CO2·（g PET melt）-1 under 4—6 MPa in the temperature range of 250—280℃.CO2 solubility in PET melt agrees well with Henry＇s law in the pressure range of 1—6 MPa.Heat of solution is obtained using the least-square method.