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Date: 12-1-2020
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Date: 17-8-2019
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Date: 26-9-2017
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UNSATURATED POLYESTERS
Unsaturated polyesters are a group of polymers and resins used in coatings or for castings with styrene. These polymers normally have maleic anhydride moiety or an unsaturated fatty acid to impart the required unsaturation. A typical example is the reaction between maleic anhydride and ethylene glycol:
Phthalic anhydride, a polyol, and an unsaturated fatty acid are usually copolymerized to unsaturated polyesters for coating purposes. Many other combinations in variable ratios are possible for preparing these resins. The 1998 U.S. production of polyesters was approximately 1.7 billion pounds.
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4 أسباب تجعلك تضيف الزنجبيل إلى طعامك.. تعرف عليها
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أكبر محطة للطاقة الكهرومائية في بريطانيا تستعد للانطلاق
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العتبة العباسية المقدسة تبحث مع العتبة الحسينية المقدسة التنسيق المشترك لإقامة حفل تخرج طلبة الجامعات
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