ヘルメット製造用射出グレード PA6 ロングカーボンファイバー 40 高強度ナイロン 6

Introduction of PA6

Nylon 6(PA6), also known as polyamide 6, has good mechanical strength and crystallization, and has the characteristics of corrosion resistance, wear resistance, etc., in the automobile industry, rail transit, film packaging, electronic appliances and textile and other major fields to achieve a wide range of applications.

Although its comprehensive performance is excellent, it also has a series of shortcomings, such as PA6 does not have strong acid and alkali resistance, low impact strength at low temperature and dry state, and its hydrophilic base will cause a high water absorption rate, and the elastic modulus, creep resistance, impact strength and so on will be greatly reduced after water absorption, thus affecting the dimensional stability of products and the electrical properties of products.

Therefore, modification research on pa6 is needed.

The drying treatment of PA6 for injection molding is easy to absorb water, so it must be attached great importance to the drying treatment before the actual processing. If the material is exposed to the air for at least 8h, it should be dried at 105℃ for more than 8h.

■ Study on modification of PA6

1. Enhanced modification

Due to the existence of hydrogen bonds in PA6 molecules, its flexibility and strength will inevitably be affected. With the increase of hydrogen bond density, the mechanical strength of PA6 will be correspondingly increased.

The more carbon atoms there are, the longer the flexible chain, the more resilient it is. The mechanical properties of PA6 composites can be enhanced by adding glass fiber.

The tetragonal zno whisker has a very high tidiness. Based on this, the results of the study on the enhancement effect of the zno whisker on the casting PA show that the composite has the highest tensile strength when the whisker content is 5%, and increasing the whisker content will reduce the heat resistance and water absorption of the material.

The fly ash was treated with silane coupling agent and then filled into the cast PA6 product for modification. The final product had better thermal stability, shrinkage rate and water absorption.

2. Flame retardant modification

The oxygen index of PA6 is 26.4, which is flammable material.

National laws and regulations clearly require the flame retardancy of polymer materials, so it is necessary to attach great importance to the flame retardancy modification of PA6 when it is used in electricity-related products.

The flame retardancy of aluminum hypophosphate is relatively good in the materials prepared by blending various metal hypophosphate salts with PA6. When the content of aluminum hypophosphate is 18%, the burning loss of the material can reach 25, and UL94 can reach V-0 grade.

Melamine cyanuric acid (MCA) modified with red phosphorus can be used as the flame retardant of PA6. Red phosphorus can hinder the formation of large planar hydrogen bond network between melamine and cyanuric acid, thus refining MCA, and MCA can form carbon under the action of red phosphorus. Therefore, modified MCA can play a flame retardant role in the condensation phase and gas phase, which is conducive to the improvement of flame retardant property of PA6.

The limiting oxygen index (LOI) of the composite was improved by adding guanidine sulfonic acid into PA6 matrix by melt blending method. The vertical combustion test showed that the yield of molten droplets was significantly reduced compared with that of pure PA6 when the addition of guanidine sulfonic acid was 3%, and the grade of UL94 was increased to V-0 when the addition of Guanidine sulfonic acid was not less than 5%.

3. 強化変性 強化変性

PA は、延性樹脂またはエラストマーを PA 樹脂に添加し、ブレンドおよび押し出すことによって得られます。

強化剤が分極 SBS である場合、分極 SBS と PA6 の強化ブレンド系は、機械的溶融混合法によって得られます。分極 SBS の量が増えると、システムのノッチ衝撃強度と材料の柔軟性も向上します。

PA6およびEPDM複合材料と比較して、無水マレイン酸でグラフトされたEPDMは、ゴムとプラスチックの適合性が高く、靭性が高くなります。

無水マレイン酸でグラフトされた EPDM の添加量が 15% の場合、ブレンドされた材料は、PA6 材料よりも 9 倍のノッチ付き衝撃強度を有していました。