BLOWING AGENT

BLOWING AGENT

Blowing agent are substances stable at room temperature and decomposes at high temperature by liberating gas.They are classified as follows
1-organic blowing agent
2-inorganic blowing agent
A good blowing agent must be filled following requirement
- Must contain large amount of releasing gas
-Must be non toxic 
-Should not produce bad smell 
-Should disperse well in rubber
-Should not influences vulcanization or Aging properties

INORGANIC BLOWING AGENT

Sodium by carbonate in combination with stearic acid and oliec acid is used to make sponge rubber.sodium nitrate combination with ammonium chloride is used to produce hollow product

ORGANIC BLOWING AGENT

It can be further classified as follows
-Azo compound
-Hydrazine compound
-Niroso compound

1-AZO COMPOUND

Diazo Amino Compound

eg:-1- Diazo amino benzene

 








 percentage used 2-3phr
  decomposition temperature 363-369K

Azo dicarbon amid

 percentage used 2-3phr
decomposition temperature 413-480K

2-HYDRAZINE COMPOUND

 

eg:-Benzene sulfohydrazine(BSH)
     decomposition temperature 363-373K
     BSH has good storage stability
3-NITROZO COMPOUND
eg:-Diniro pentamethylene tetramine(DNPT)
      decomposition temperature-205
DNPT are used to make micro cellular sheet(like hawai chappals)