Solvent Selection Based on HANSON Solubility Parameters
The Aim:
We aim to find a solvent for polyisoprene, since our AC1 is mainly composed of polyisoprene as its backbone, and the solvent should be a non-solvent for polystyrene, because we are going to cast the AC1 coating on a PS substrate. Therefore, I tried this theoretical mean to predict a suitable solvent.
Hanson (1967) developed the Hildebrand solubility parameter, and he quantified the cohesive energy density ?2 between two substances based on dispersive force, polar interaction and hydrogen bond interaction, as follow:
………………………………………………………….(1)
Where:
D = dispersive force
P = polar interaction
H = hydrogen bond interaction
A low molar mass compound can be described by the three parameter values, ?D, ?P, and ?H.
A polymer is described not only by these three values but also by a parameter called interaction radius, R0, which is the radius of the “solubility sphere” in the “2?D-?P -?H” space. In this space, the three parameters determine a center of a sphere, which has the R0 as its radius.
Also in this space, a low molar mass compound can be positioned as a dot based on its parameters, and if the compound is within the space limited by the “solubility sphere”, it is a solvent for the polymer, and vice versa. The distance between the center of the “solubility sphere” and the position the compound belongs to is expressed as below:
Where:
S = solvent
And the letter P following to the comma refers to polymer.
Usually, the ratio DS-P/R0 is used as the criterion:
DS-P/R0 > 1 ? the compound is a non-solvent;
DS-P/R0 < 1 ? the compound is a solvent;
DS-P/R0 = 0 ? the compound may cause swelling.
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 .
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