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Karlo Vizec

What is the limiting oxygen index test for polymer composites?

Amos Ekeson  Follow

Polymer composites are generally fibre reinforced resins which consists of wide range of application viz. aerospace to space goods. Despite being high cost, they have gained popularity world wide. Out of all these applications, which area of study are you looking after ?

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Austin Mccormack  Follow

Limiting oxygen index (LOI) is a value that is related to the minimum quantity of oxygen that is needed so that the burning of polymer material continues. It is a major examination of polymers and there are standard methods to measure LOI and interpret it. The story of LOI is too long, so I suggest you to refer to related sources. You can start with general sources (such as, Wikipedia and polymers encyclopedia) and then read the specific books.

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Chris Harrington  Follow

It is a polymer blended with another substance, such as a mineral, fiberglass, carbon fiber, modified clays, etc. For example carbon fiber tenis raquets are not just carbon fiber. They are a carbon fiber epoxy composite. Same for fiberglass items. The fiberglass needs a binding polymer to hold it together, usually epoxy. Many applications of polymers use polymer composites. They can lower the cost. They can greatly improve the properties: strength, temperature resistance, etc.

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Andrea McCurdy  Follow

Yes. For determining the flexural strength of a composite, the four point bending test is suggested.

ASTM D7264 is the standard test method for determining flexural properties of polymer matrix composite materials. This method determines the flexural properties (including strength, stiffness, and load/deflection behavior) of composite materials under the standard conditions defined. It contains two procedures, Procedure A is used for three-point loading and Procedure B is used for four-point loading. For testing composite materials, four point bending tests are usually preferred.

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David Bortin  Follow

Polymer matrix composite (PMC) has polymer as matrix and usually other strong constituent like ceramic particles or graphene as dispersed phase.

Polymers generally have very good resistance to chemical attack, have good for ability and have low specific gravity. These properties when combined with the strength of ceramic particles or other dispersed phase results in an excellent condition of properties like very high strength to weight ratio, corrosion resistance etc.

Thank you.

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Charles MacKay  Follow

Stolen from Wikipedia

“Carbon suboxide spontaneously polymerizes at room temperature into a carbon-oxygen polymer, with 3:2 carbon:oxygen atomic ratio. The polymer is believed to be a linear chain of fused six-membered lactone rings, with a continuous carbon backbone of alternating single and double bonds. Physical measurements indicate that the mean number of units per molecule is about 5–6, depending on the formation temperature”

Oxocarbon polymer is the term you'd Google to find this information.

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Bergen Furniture And Design  Follow

Hey Dr. Z Akaria thanks for the query but to be honest I read about this testing after checking this question and personally feel that its really useful. So this is the easiest explanation I could find from the google source specified below for your reference.

Limiting Oxygen Index Testing (LOI), is a very widely used method for determining the relative flammability of polymeric materials.

A numerical index, the LOI, is defined as the minimum concentration of oxygen, in a nitrogen/oxygen mixture, which is required to just support combustion of the test sample under conditions of the test.

The higher the value of the LOI the greater the fire retardancy.

Standards

The LOI test conforms to the following standards.

  • ISO 4589-2
  • BS2782 (part 1 method 141)
  • ASTM D2863

Source :-Limiting Oxygen Index Testing & Analysis (LOI) - ITRI Lab UK

Hope it helps!!!!!!!!!!!!!!

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David Vanderschel  Follow

A Composite is made up of matrix & filler or reinforcement. Polymer acts as the matrix & a non-polymer acts as a filler. Polymers can be either natural or synthetic. Eg : Wood - Lignin & Hemicellulose act as the polymer matrix while cellulose fibers acts as fillers.The uniqueness about a Composite is both elements maintain their individual properties even after integration.

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