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Date: 2-10-2017
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Date: 29-9-2017
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Date: 26-5-2020
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EPOXY RESINS
Epoxy resins are produced by reacting epichlorohydrin and a diphenol. Bisphenol A is the diphenol generally used. The reaction, a ring opening polymerization of the epoxide ring, is catalyzed with strong bases such as sodium hydroxide. A nucleophilic attack of the phenoxy ion displaces a chloride ion and opens the ring:
The linear polymer formed is cured by cross-linking either with an acid anhydride, which reacts with the -OH groups, or by an amine, which opens the terminal epoxide rings. Cresols and other bisphenols are also used for producing epoxy resins.
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10 دقائق قبل النوم.. هذا الأسلوب يساهم في تحسين يومك
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الأسباب الشائعة لتفريغ شحن البطارية
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قسم المشاريع الهندسية: مواد معمل العطاء الأوّلية الإنشائية تطابق المواصفات القياسية
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