Youngs Modulus Of High Impact Polystyerene
Youngs Modulus Of High Impact Polystyerene
(OP)
I am searching for the accurate value of virgin High Impact Polystyrene Material.
Could any one help me please?
Could any one help me please?
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Youngs Modulus Of High Impact Polystyerene
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RE: Youngs Modulus Of High Impact Polystyerene
My advice is to either take a value of ~2.25 GPa as typical, or even better find the datasheet for the grade that you are interested in. All such datasheets are available from the manufacturer for example. You will also find the CAMPUS database very useful for finding materials properties as well as www.matweb.com where you can find huge amounts of materials data free.
RE: Youngs Modulus Of High Impact Polystyerene
I am working on Mechanical Properties of HIPS composites. I have one more query regarding this. If I add glass beads to the virgin matrix, effectively the yield strength should decrease. But in my case it increases. I do not know the reason. When I try to analyse, I find that because of the structure of glass beads, they create a week interface and hence the properties decrease.
What do you suggest?
RE: Youngs Modulus Of High Impact Polystyerene
You're welcome. You are right, adding glass beads will always decrease the yield strength. Any isortropic (round) filler in any matrix will tend to decrease the yield strength. I have lots of data to show that.
Anisotropic particles (some talcs, mica, glass fibres) increase yield strength for a variety of reasons. Firstly, they have more surface area : volume ratio and so they give better bonding to the matrix. Also they align when you injection mould your test parts and that gives a falsely high yield strength.
Does that help? If not ask me one more time and explain a bit more what you are seeing.
RE: Youngs Modulus Of High Impact Polystyerene
I tried to use the Nicolais and Narkis equation and my reading were well compatible to the equation. Are there any more theories support this?
Thank you for your help.
Regards,
Krunal
RE: Youngs Modulus Of High Impact Polystyerene
I am happy to have been of service. I have loads of data to support that but I can't show it here I have data on filled polymers for example and also for impact modified polymers including HIPS and ABS. I even give courses on it and I work for one of the world's largest manufacturers of plastics so I am exposed to this stuff daily.
Basically to find the modulus of the mineral filled polymer or the rubber filled polymer the method is the same. The modulus changes linearly with the volume % of particles added. So you just need to know the modulus of the particles you are adding and then you can calculate the modulus for the composite. That only works for isotropic particles though, but the rubber particles are spherical so it works for HIPS and ABS or for polymers filled with CaCO3 for example. For rubber you can probably assume a modulus of zero or near zero.
You are right that the Micolais and Narkis equation can also be applied to this type of situation. There are other equations too. Adding rubber will also lower the yield strength and naturally improve the impact resistance.
RE: Youngs Modulus Of High Impact Polystyerene
Perhaps a silly question, but why don't you just get your actual material tested? I know it costs a few $$, but that will get you by far the most accurate values. I agree completely with Demon3's first reply here in that one formulation varies greatly from the next. That alone is enough reason for me to never use any type of standard data sheet, because the margin of error between those numbers and my actual materials is usually much bigger than I want it to be. So, I would suggest contacting some materials testing lab (like Axel Products, they've given me some great data in the past) and getting one or more formulations of your material tested.
Ron
RE: Youngs Modulus Of High Impact Polystyerene
Thanks gentlemnen for helping me.
Keep Posting.
Krunal