tailieunhanh - Ảnh hưởng của quá trình xử lý nhiệt

Nanocomposit của Nanomer@I30E và cao su thiên nhiên được chế tạo và nghiên cứu cấu trúc. Quá trình trộn được tiến hành trên máy trộn 2 trục ở các điều kiện khác nhau. Cấu trúc của clay trong nền cao su được khảo sát bằng phổ XRD và SAXS. Bằng cách trộn sơ bộ trên máy trộn 2 trục, sau đó hỗn hợp được xử lý nhiệt ở nhiệt độ cao (khoảng 1000C) khoảng cách giữa các lớp có thể đạt đến 5,17 nm khi xử lý trong tủ sấy và đạt đến trên 4,73 nm khi xử lý trong lò vi sóng. Trong một số trường hợp có thể có cấu trúc tách lớp. | Science & Technology Development, Vol 14, 2011 EFFECT OF HEAT TREATMENT ON NANOCLAY DISPERSING IN NATURAL RUBBER Do Thanh Thanh Son University of Technology, VNU-HCM (Manuscript Received on November 09th, 2008, Manuscript Revised December 08th, 2010) ABSTRACT: Nanocomposites of Nanocor® and natural rubber grade SVR 3L are investigated. The mixing process is conducted by two-roll mill at different conditions. The structures of clay in rubber matrix are characterized by XRD and SAXS. By premixing the material by two-roll mill at room temperature following with treating at high temperature (about 100°C) the interlayers spacing can reach to 5,17nm in case of surface heating in an oven and and more in case of internal heating in microwave oven. In some cases an exfoliation can be attained. Keywords: nanocomposite, natural rubber, XRD, SAXS. Three 1. INTRODUCTION Properties of clay/rubber nanocomposite depend much more on structures of nanoclay in rubber matrix. They may be intercalation, main factors that affect the dispersing of nanoclay in melt polymer matrix are thermodynamics, diffusion and stress[1]. Thermodynamics is related to the exfoliation or disordered structures or a interactions of polymer and modifying agent in mixture of them. In general, in natural-clay organoclay. The change of free energy of filled polymers with favorable thermodynamics mixing process: for nanocomposite formation, the structure is ∆G = ∆H - T∆S. characterized by a coexistence of exfoliated, In the intercalation process, the intercalated and disordered layers. The mixed conformation entropy of polymer chains exfoliated/intercalated structure is intrinsic in decreases when polymer molecules are forced MMT-based nanocomposites and originates to be confined inside the narrow silicate from the chemical and size inhomogeneities of interlayer. So that high temperature is not the MMT layers. This behavior is common for favorable to the .