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Packaging polymers

8 August 2011 No Comment

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Having thought recently about polymers present in the food I buy, it was only a short step to considering that my shopping basket also contained a great variety of polymers in terms of packaging materials. Even the reusable shopping bags I prefer to use nowadays, usually contain considerable amounts of synthetic polymers.

Polymers in packaging

Food packaging solutions are rapidly becoming more sophisticated with options that can be re-sealable, stand-up or hermetically sealed. They also must deliver to a wider range of user and food safety demands such as the need to be microwaveable and able to eliminate atmospheric pathogens. Whatever the final specifications of these new packaging materials, of course, they all still need to be able to fulfil their core function of keeping their contents safely inside.

As a result, the requirements for the mechanical properties of polymer-based packaging materials is becoming more varied. Two of the most important factors however are the molecular weight (MW) and the molecular structure ( i.e. branching) influencing for example the polymer’s density and rigidity.

Easy high temperature polymer dissolution

Analyzing polymer MW and branching parameters by Gel Permeation Chromatography (GPC) of polyolefins is difficult because they first have to be dissolved. A process which requires unpleasant solvents and high temperatures.

Traditionally polymer dissolution was not a popular job in the lab – if it was attempted at all – as it is not pleasant handling these solvents at temperatures up to 170 degrees. However this is now changing with the introduction of our automated high temperature GPC system. Now it’s a bit more popular a task as, once set up, all the operator has to do is sit back and let the system take care of the nasty bits!