Table of Contents:
TA Tip
- Optimum utilization of the internal database
New in the sales program
- The new STARe SW V4.0
- The new TGA module TGA/SDTA851e
Applications
- Determination of the eutectic composition of the system
- Glass transition temperature of elastomers
- PEI, glass transition by ADSC
Methyl-4-hydroxybenzoate/ p-hydroxybenzoic acid
Experimental aim
p-hydroxybenzoates are used as preserving agents and contain minor amounts of free 4-hydroxybenzoic acid as an impurity resulting from the synthesis with which they form a eutectic mixture. The example of the system methyl-4-hydroxybenzoate/ p-hydroxybenzoic acid will be used as an example to determine the composition of the eutectic.
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Experimental aim
The temperature of the glass transition (Tg) is suitable for the characterization, identification and quality monitoring of elastomers.
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Sample
Polyetherimide, PEI, Ultem 1000, injection molded part
Conditions
DSC Cell: DSC821 with sample changer and cryostat cooling Pan: Al standard 40 μl Sample preparation: 17.546 mg cut with knife in such a way that the bottom is flat DSC Measurement: Heating from 200 to 229 ° C at a mean rate of 1 K/min. Amplitude of sinusoidal oscillation 1 K, period 1 min
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