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Polymers

Ubiquitous use of polymers in technology and in our daily lives is due to their excellent chemical and physical properties, processability and relatively low cost. The vast application of polymers is only possible through development and understanding of polymer properties and behavior. Whether polymer nanostructures or polymer nanocomposites (PNC), a variety of research investigations can be performed with Anton Paar’s TORC 5000. Read below about the investigation of polymers with thermo-optical oscillating refraction characterization for nanoparticle influence on reaction and physical polymer properties.

Nanoparticle influence on reaction and physical properties of the polymerized sample matrix

Introduction

The polymerization reaction and material properties of polymers can be strongly influenced by adding pigments, co-polymers and fillers. Nanomaterials can be used as they exhibit greater deviating influences on polymer properties than their macro counterparts. Glass transition of amorphous regions interacts with semi-crystallin polymer sections. This can, e.g., form components with high temperature resistance, but also better ductility properties. Investigating the influence on the polymerization properties, e.g. reaction speed or chemically induced glass transition (vitrification), is necessary for research purposes. The TORC allows live reaction monitoring with analysis of reaction speed, and kinetic and sample changes by refractive index.

Experimental

Polymerization example: Resin diglycidylether of bisphenol A (DGEBA) and of the hardener diethylene triamine (DETA) with a mass ratio of 100 g:20 g +1% addition of nano-sphere PMMA.

The comparison can either be performed without PMMA additive or with macroscopic PMMA of an average molecular weight of 120.000 GPC.

Characterization techniques and parameters: TORC 5000. Add the sample with a size of 100 µL premixed. Set standard polymerization conditions for polymerization of e.g. 100 °C and TORC specific parameters of 30 s period and 0.5 °C amplitude.

Results and discussion

The TORC technique allows an inside view into reaction speed, temperature influence and reaction kinetics.

The influence of the nanoparticles on these processes can be observed by comparing the TORC results with reference results from mixed samples without nanoparticle additives. This interference can, e.g., result in lower sensitivity to temperature conditions. The origin temperature dependent on the reaction speed and vitrification process for DGEBA + DTEA at a ratio of 100 g:20 g and with a PMMA polymer filler – or even without filler – was two times more temperature-dependent than the reaction with nano-sphere PMMA particles. The reaction temperature dependence observed is close to the Arrhenius rule behavior of doubled reaction speed by 10K temperature improvement. In this instance, the materials didn’t only improve their properties, they could even be applied across wider environmental conditions.

Additional information

Instruments:

TORC 5000

Source:

PHILIPP, Martine, et al. Polymerization-induced shrinkage and dynamic thermal expansion behavior during network formation of polyurethanes. Thermochimica Acta, 2019, 677. Jg., S. 144-150. www.sciencedirect.com/science/article/abs/pii/S0040603118309845
MÜLLER, Ulrich, et al. Temperature modulated optical refractometry: A quasi-isothermal method to determine the dynamic volume expansion coefficient. Thermochimica acta, 2013, 555. Jg., S. 17-22. www.sciencedirect.com/science/article/abs/pii/S004060311200593X

Application report:

Characterizing the curing reaction

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