The application of silane coupling agent in a composite mate

1 the introduction

 

Silane coupling agent were the earliest people to study, the earliest application of coupling agent, because of its unique performance and new products constantly, make its application gradually expanded, has become an important branch of organic silicon industry. Around 1945 by the American union carbon (UC), and companies such as dow corning (DowCorning) developed a series of typical structure of silane coupling agent; In 1955, first put forward by the UC company contain amino silane coupling agent; Starting in 1959, a series of modified amino silane coupling agent; 6 o s of the 20th century appeared the silane coupling agent containing a oxygen radicals, appeared in the late 60 s with diazo and azide structure of silane coupling agent. In recent decades, with the development of glass fiber reinforced plastic, promote the research and development of various kinds of coupling agent. Modified amino silane coupling agent and silane coupling agent had oxygen radicals and azide synthesis and application of silane coupling agent is the main result of this period. Our country began to be developed in the middle of the 2 o century 6 o s silane coupling agent. First began to be developed by the institute of chemistry, Chinese Academy of Sciences, functional silane coupling agent, nanjing university also began to develop functional silane coupling agent. In this paper, only the silane coupling agent on the application of composite materials.

 

2 coupling mechanism of silane coupling agent and the function

 

Silane coupling agent is a kind of organic silicon compound with special structure. In its molecule, both with inorganic materials such as glass, cement, metal, etc.) in combination with reactive groups and with organic materials, such as synthetic resin, etc.) in combination with reactive groups. Commonly used the surface of the chemical bond theory, theory of infiltration theory and deformation layer theory and constraint theory, etc. B. Arkles according to the coupling process of the coupling agent four steps reaction model is put forward, namely: (1) are connected to the silicon atoms of the SiX basic hydrolysis, generate SiOH; (2) the dehydration condensation between si - OH, generate low polysiloxane containing si - OH; (3) low SiOH of polysiloxane with OH forming hydrogen bond on the surface of the substrate; (4) in the process of heating curing with dehydration reaction with the base material to form a covalent bond connection. It is generally believed that silane coupling agent on the interface of hydrolysis of the generated three silicon hydroxyl only one and base material surface bonding; The remaining two si - OH, or with other si - OH condensation of silane, or in the free state. Therefore, by silane coupling agent can make the two kinds of material interface coupling up performance difference is very big, so as to improve the performance and increase the bond strength of composite material, and get excellent performance and reliable new composite materials. Silane coupling agent is widely used in rubber, plastics, sealants, adhesives, paint, glass, ceramics, metal corrosion, etc. Now, silane coupling agent has become one of essential additives in the material industry.

 

Three silane coupling agent on the application of composite materials

 

(1) as surface modification agent. Particle surface coupling modification in the coupling reaction, the particle surface via coupling