Trong thời gian gần đây, vật liệu cao su nanocomposite đã được tập trung nghiên cứu nhiều. Khác với các hệ độn truyền thống, các hạt độn trong vật liệu cao su nanocomposite có kích thước rất nhỏ, khoảng từ 1–100 nm. Điều này làm cho vật liệu cao su nanocomposite có những thuận lợi và hạn chế riêng khi so sánh với cao su truyền thống. Phần tài liệu sau sẽ đề cập cụ thể về vấn đề này.

…

2.1.2.1 Advantages of Rubber Nanocomposites

In comparison with conventional composites, the main advantages of nanoreinforcements are summarized as follows:

1. Nanomaterials are more effective reinforcements because smaller fraction of nanomaterials causes a significant improvement of the matrix properties, leading to lightweight composites with lower cost and easy processability.

2. The load transfer from the matrix to the reinforcements is more efficient in case of nanocomposites due to their increased surface area, assuming good adhesion at the interface.

3. The crack propagation length at the interface becomes longer because of the size reduction of nanomaterials, which improves both strength and toughness.

It is well known that the particle size, structure and surface characteristics of reinforcing agents are three main factors that determine their reinforcing ability. Particle size is the primary determinant among these three factors and this point is supported by Hamed [1]. In fact reinforcement, especially reinforcement of nanofillers, is essential for rubber products.

2.1.2.2 Challenges of Rubber Nanocomposites

Although nanoreinforcements enhance overall material performance, there are still challenges facing nanocomposites.

1. Nanoparticles tend to aggregate during manufacturing processes. The severe particle aggregation is detrimental to the thermal and mechanical properties of the nanocomposites. The homogeneous dispersion of the nanoparticles in matrix is critical to obtain high performance nanocomposites.

2. Health and environmental threats can occur from the production, use and disposal of nanoparticles. Nanoparticles can damage the body’s natural defenses or cause increased responses to common allergens. Workers in nanotech industries are at risk of exposure to high concentrations of nanoparticles. Nanoparticles used in consumer products may threaten public health. Already it is known that nanoparticles in air pollution can be up to 50 times more damaging to lung tissue than fine particles of the same chemicals.

…

Trích đăng từ sách Rubber Nanocomposites: Preparation, Properties and Applications, Sabu Thomas và Ranimol Stephen, Wiley, 2010, trang 22 – 23

Nguồn: www.books.google.com.vn

(vtp-vlab-caosuviet)