温度梯度相互作用色谱在聚烯烃表征中的应用

Application of polyolefin characterization technique based on thermal gradient interaction chromatography

研究了高温-温度梯度相互作用色谱(HT-TGIC)在聚烯烃表征中的应用,并与结晶分级技术进行了对比,同时分析了实验条件对HT-TGIC曲线的影响。实验结果表明,相比结晶分级技术,HT-TGIC在表征结晶度较低或完全无定形树脂时具有明显优势。HT-TGIC可用于定量表征聚烯烃树脂及其共混物的化学组成分布,并具有良好分辨率。优化的操作条件为:尽可能快的冷却速度、升温速率/淋洗流量的比值在一定范围内、动态降温、较小的动态吸附流量、冷却循环最终温度高于结晶温度。利用辛烯含量差与HT-TGIC淋洗峰偏离值呈线性关系,可快速确定共聚单体含量,包括高共聚单体含量树脂。

Compared with crystallization-based fractionation techniques,the high temperaturetemperature gradient interaction chromatography(HT-TGIC)was investigated in the characterization of polyolefins.The influence of experiment conditions on HT-TGIC curves was analyzed.Results show that HT-TGIC has clear advantages in the characterization of low crystallinity or completely amorphous resin compared with the crystallization-based fractionation techniques.HT-TGIC can be used to quantitatively characterize the chemical composition distribution of polyolefin resins and their blends,with good resolution.The optimized operating conditions were the fastest possible cooling rate,a certain range of the ratio of temperature rise rate to elution flow rate,dynamic cooling,a small dynamic adsorption flow rate,and a final cooling cycle temperature higher than the crystallization temperature.Using the linear relationship between the octene content difference and the HT-TGIC elution peak deviation,the comonomer content,including high comonomer content resins,can be quickly determined.