as the solvents used to dissolve them; as can be observed some of them require high temperature in order to be run by GPC. Most of the rubbers can be dissolved in toluene at 75◦C. Most of the amorphous polymers can be prepared at room temperature, but semicrystalline polymers require high temperatures to be dissolved.
Branching High temperature GPC equipment generally counts with different types of detectors such as refractive index, light scattering, and viscometer, among others; using these detectors it is possible to obtain the absolute MW, and in most cases it is not necessary to construct a calibration curve. A viscometer detector also provides information about the level of branching of a polymer; in fact, using this it is possible to obtain the index of branching (g), which is defined by the following equation [28]: g = η1 ηb (17.3) where η1 is the intrinsic viscosity of the linear polymer and ηb is the intrinsic viscosity of the branched polymer (of the same chemical nature and same molecular weight).
Sample Preparation A small sample of polymer is weighed (10 mg) and placed in a 15-ml stainless steel vial. Then, 10 ml of 1,2,4-trichlorobenzene is added to the vial and the sample is placed in an oven at 120◦C for 3 h. A stabilizing agent, such as Irganox 1010, should be added to the solvent to avoid degradation of the polymer during the dissolution period. Once the polymer is solubilized, a stainless steel filter is placed on top of the stainless steel vial; the filter is pushed down, thus the solution is filtered; in this step, any contaminants are removed from the solution.
as the solvents used to dissolve them; as can be observed some of them require high temperature in order to be run by GPC. Most of the rubbers can be dissolved in toluene at 75◦C. Most of the amorphous polymers can be prepared at room temperature, but semicrystalline polymers require high temperatures to be dissolved.Branching High temperature GPC equipment generally counts with different types of detectors such as refractive index, light scattering, and viscometer, among others; using these detectors it is possible to obtain the absolute MW, and in most cases it is not necessary to construct a calibration curve. A viscometer detector also provides information about the level of branching of a polymer; in fact, using this it is possible to obtain the index of branching (g), which is defined by the following equation [28]: g = η1 ηb (17.3) where η1 is the intrinsic viscosity of the linear polymer and ηb is the intrinsic viscosity of the branched polymer (of the same chemical nature and same molecular weight).ตัวอย่างขนาดเล็กเตรียม A ตัวอย่างของพอลิเมอร์คือ ชั่งน้ำหนัก (10 มิลลิกรัม) และอยู่ในคอนแทคเลส 15 ml แล้ว คอนแทคที่เพิ่ม 10 ml ของ 1,2,4 trichlorobenzene และตัวอย่างจะถูกวางในเตาอบที่ 120◦C สำหรับ 3 h ควรจะเพิ่มเป็นตัวแทนสมัยมีเสถียรภาพ เช่น Irganox 1010 ตัวทำละลายเพื่อหลีกเลี่ยงการสลายตัวของพอลิเมอร์ที่ช่วงยุบ เมื่อพอลิเมอร์เป็น solubilized, filter เหล็กกล้าไร้สนิมอยู่บนคอนแทคสเตนเลส filter ถูกผลักดันลง จึง เป็น filtered ในขั้นตอนนี้ สารปนเปื้อนใด ๆ จะถูกเอาออกจากโซลูชัน
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