Agilent Technologies Repeatability in High Temperature Polypropylene Analysis Using Agilent PLgel MIXED-B 技术手册说明书.PDF

Repeatability in High Temperature P lypr pylene Analysis Using Agilent PLgel MIXED-B Technical Overview Intr ducti n A gel permeation chromatography system comprising Agilent P gel MIXED-B columns and the Agilent P -GPC 220 integrated, high temperature instrument is ideally suited to the analysis of polypropylene. The ability of the system is demonstrated in a repeatability study using six polypropylene injections. A commercial sample of PP was prepared at 1.5 mg/m using the P -SP 260 sample preparation system with a dissolution temperature of 160 °C and a dissolution time of two hours. Six aliquots of the master batch solution were dispensed into the P -GPC 220 autosampler vials and placed in the carousel where the hot zone temperature was 160 °C and the warm zone 80 °C. Figure 1 shows an overlay of the raw data chromatograms obtained for the six consecutive injections of the sample. 7 min 32 F gure 1. An overlay of the raw data chromatograms obta ned for s x consecut ve polypropylene nj ect ons. The data were analyzed against a polystyrene standards calibration using the follow- ing Mark-Houwink parameters to obtain the polypropylene equivalent molecular weight averages shown in Table 1. Polystyrene in TCB1 K = 12.1 × 10-5 a = 0.707 Polypropylene in TCB2 K = 19.0 × 10-5 a = 0.725 Table 1. Calculated Molecular We ghts for S x Inj ect ons of Polypropylene and Calculated % Var at on Injecti n number Mp Mn Mw 1 127,132 65,086 185,795 2 131,893 65,089 185,236 3 128,673 66,802 186,202 4 132,062 67,417 188,048 5 131,625 69,320