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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: HAG on April 25, 2009, 11:11:18 AM

Title: Cristallinity calculation
Post by: HAG on April 25, 2009, 11:11:18 AM

I have to calculate the cristallinity of a polyethylene/starch blend. I used a DSC to measure the amount of heat that was emitted during crystallization. In order to calculate the crystallibity of my blend, I have to divide this amount of heat by the amount of heat emitted by the crystallization of 100% polyethylene, is this correct? If so, how can I find/calculate the heat emitted during crystallization of 100% polyethylene?


Sorry but my English isn't perfect

Title: Re: Cristallinity calculation
Post by: ARGOS++ on April 25, 2009, 11:57:52 AM

Dear HAG;

Maybe that these are already of some help to you?:
           http://www.engr.utk.edu/mse/pages/Textiles/Polymer%20Crystallinity.htm
           http://www.tainstruments.co.jp/application/pdf/Thermal_Library/Applications_Briefs/TA123.PDF

Otherwise search the Net for: "polymer crystallinity DSC"

Good Luck!
                    ARGOS⁺⁺

Title: Re: Cristallinity calculation
Post by: HAG on April 25, 2009, 12:48:25 PM

Thanks!

I'm starting to get it! I will have to divide the heat given during crystallization by 293g/J (other sources give the same amount). To make sure, I added an attachment of a DSC of one of my materials. The heat during crystallization is 38,7 g/J.

=> 38,7/293 = 0,13 => 13%


Purple is the first heating, black cooling, green second heating

Title: Re: Cristallinity calculation
Post by: ARGOS++ on April 25, 2009, 12:58:08 PM

Dear HAG;

Quote from: HAG on April 25, 2009, 12:48:25 PM

the heat given during crystallization by 293g/J .  The heat during crystallization is 38,7 g/J.

I believe you mean: 38.7 J/g! - and also 293 J/g!
Then the results seems to make sense.

Good Luck!
                    ARGOS⁺⁺

Title: Re: Cristallinity calculation
Post by: HAG on April 26, 2009, 03:21:16 PM

Ok, thanks for the *delete me*

Title: Re: Cristallinity calculation
Post by: ARGOS++ on April 26, 2009, 03:41:26 PM

Dear HAG;

You 're welcome!   ─   Soon again.

Good Luck!
                    ARGOS⁺⁺