14.1 Masterbatch
The ultimate purpose of mixing rubber is to disperse filler into the rubber matrix. With
carbon black the dispersion process may be stated as,
agglomerate aggregate
100-10 ?m 100-10 nm
The process of carbon black manufacture may be stated as
primary particle agglomerate (and pellet)
100-10 nm 100-10 ?m (and larger)
The question is whether or not the primary particles can be directly mixed into the
rubber.
The size of latex particles of the emulsion-polymerised rubber is less than 100 nm. This
size corresponds to the domain size of rubber after the mixing is completed. It follows
that if the primary particles of carbon black are added to rubber latex, satisfactory mixing
may be achieved [1]. This is easier said than done.
First of all, the primary particles of carbon black are small, being invisible or at best like
smoke. There is a handling problem. If the particles are suspended in water, they tend to
flocculate. When the aqueous suspension of carbon black is added to the rubber latex,
the mixture tends to consist of flocculates of carbon black and flocculates of rubber
particles. The latter flocculation occurs, because the latex contains a minimum amount
of emulsifier and thus it has minimum colloidal stability. Any change of the condition
tends to bring a loss of stability. Once the separate flocculates are formed, additional
mixing is required for improving dispersion. However, this approach offers an opportunity
for developing innovative mixing processes.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
الرجوع الى لوحة التحكم
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