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Summary The molecular weight distribution of

is obtained with Size Exclusion Chromatography (SEC).

The results are shown in the table.

SEC Summary information

Weight Average Molecular Weight = Number Average Molecular Weight = Z Average Molecular Weight = Polydispersity index =

Table 1: MWD of CAS

The oligomer fraction > 452 g/mol and < 500 g/mol = and the oligomer fraction > 452 g/mol and < 1000 g/mol =Introduction

This method is applicable for the determinat ion of molecular weight distribution of Joncryl resins or other resins which are soluble in tetrahydrofuran (THF). Size exclusion chromatography (SEC) is a chromatographic method in which particles are separated based on their mole cular weight (size) or even better their hydrodynamic volume.

Figure 1: Illustration of the SEC theory.

The samples are dissolved in THF and the sample solution is injected into a liquid chromatography (HPLC). Separation is made on a SEC column set and is

monitored with a refractive index detector. The molecular weight distributions of the samples are determined with a polystyrene calibration curve. The calibration curve is based on standards with known molecular weight.

Experimental work

Reagents

Tetrahydrofuran (stabilised with 0.025% BHT, dry solvent): HPLC grade,

available from Fisher Chemicals (productnr. T/0701/17) or equivalent. PS-1 EasiCal standards: Mw 580 -7500000 Da, available from Polymer Labs, Varian Inc. (part nr. 2010-0505).

Materials

1.8 ml GC or HPLC vials and caps. Capper.

4 decimals balance. 3 ml disposable polyethylene pipets. 10-100 μl variable eppendorf pipet and tips. 100-1000 μl variable eppendorf pipet and tips. 1000-10000 μl variable eppendorf pipet and tips.Instrumental operating conditions

Instrument: WATERS 2690 separations module with an on-line degasser

Detector:

WATERS 2414 Refractive inde x detector, temperature detector = 40 °C

SEC column set: 1 × PL gel guard 10 μm MIXED B (1110-12 20, 50*7.5 mm) + 2 × PL gel 10 μm MIXED B (1110-6100, 300*7.5 mm) in serial. Mobile phase:

100% THF Column temperature:

40 °C Injection volume: 50 μl

Elution time:

26 min

Flow rate:

1 ml/min

EZChrom Elite of Scientific Software, In c. was used as a data acquisition system.

Sample preparation

SEC calibration

For the SEC calibration 0.1 m/v % soluti on of the polystyrene standards were prepared in the mobile phase (THF). The standards were allowed to dissolve by gently stirring or shaking of the solution and with t hese standards a first order

calibration curve was established.

Sample measurement

The samples were also dissolved in th e mobile phase. 100 μl of a formulation was dissolved in 1.8 ml to get 0.025 m/ v % solution. The polymers were allowed to disperse by gently stirring or shaking of the solution.

Results and conclusion

The system was calibrated with 10 narro w standards of polystyrene, so all molecular weight distributions ar e quoted relative to polystyrene.

Based on the retention times and the nominal average molecular weights ( M

w ) supplied by Polymer Laboratories a 1 e first order calibration curve and an equation were generated with EZChrom Elit e. Figure 1 shows the calibration

curve and the raw data of the standards.Figure 1: 1 e first order calibration curve of polystyrene standards.

The molecular weight distribution of was determined with a 1 e

order calibration curve.

**Error! Objects cannot be created from editing field codes.** Figure 2: SEC chromatogram of

Minutes 0 2 4 6 8 10 12 14 16 18 20 22 24 26mVolts

-100 0 100 200 300mVolts

-100 0 100 200 300

The results are shown in table 2.SEC Summary information

Processing Start Time(min) = Processing Stop Time(min) = Reference peak Offset Time(min) =

Number of Slices =
Weight Average Molecular Weight =
Number Average Molecular Weight =
Z Average Molecular Weight =
Z+1 Average Molecular Weight =
Polydispersity index =
Peak Molecular Weight = Z Average / Weight Average =
Z+1 Average / Weight Average =

Table 2: MWD of CAS

The oligomer fraction > 452 g/mol and < 500 g/mol = and the oligomer fraction > 452 g/mol and < 1000 g/mol =APPENDIX 1: Slice report CAS