Abstract:  Polysulfide sealants have high resistance against ultra violet radiation and environment, exhibit good lowtemperature properties, low water -vapor transmission, and resist against solvents and chemicals. They were many
publications on the characterization of metal peroxides-cured polysulfide, reporting the results of thermogravimetry analysis, dynamic mechanical analysis, tensile strength and hardness test. Although the polysulfide rubber has the
advantage of lower cost, they faced the strong challenges from silicone and polyurethane-based sealants. One of the main reasons is their relatively poor tensile properties and weak adhesive strength.
The new multi?alkoxyorganosilane coupling agents with hydroxyl-amine group( M AGHA) are synthesized by addition of Y -aminopropyltriethoxysilane ( KH550) and Y -glycidoxypropyltrimethoxysilane (KH560) . T he influence
to the polysulfide sealants by the multi -alkoxyorganosilane coupling agents with hydroxyl?amine group as additive are studied. With a small amount of MAGHA, the commercial polysulfide-based sealants have significant improvement
in mechanical properties. In our polysulfide composition, the methoxy or ethoxy can be reacted with hydroxyl on the surface of the filler. Hydroxy group of the new multi-alkoxyorganosilane coupling agents or water produced by
oxidation between polysulfide and MnO 2 can make MAGHA to create the three -dimensional structure of polysiloxane through MAGHA polycondensation. The three-dimensional structure of polysiloxane has ability to package the
surrounding of fillers and enhance the chain of polysulfide sealant through interreacted pendent with hydroxyl-amine group of MAGHA which can improve the tensile strength and ultimate elongation of sealant simultaneously.
The test results show that 1% of multi-alkoxyorganosilane coupling agents with hydroxyl-amine group could help increasing 30% in the ultimate elongation and 70% in the tensile strength of the polysulfide sealants. The
adhesive strength to steel also increased significantly. Since MAGHA reinforcement significantly increased the bulk tensile strength of polysulfide sealants, while M AGHA has the special hydroxyl-amine structure, which is the
foundation of epoxy resin for its high properties of adhesive. When KH560 added to polysulfide sealants, the adhesive strength has no significant changed. Dynamic mechanical thermal analysis shows the T g of polysulfide
sealant have increased about 5- . It may due to the increased cross-link by the result of the new multi - alkoxyorganosilane coupling agents with hydroxyl-amine group effect to SH and fillers. T he movements of main
chain are limited. It also increased the ability on water. From water absorption test, the polysulfide sealants added MAGHA appear excellent properties of water absorption and resistance. After 18-day immersion, the polysulfide
sealants before modification absorbed more than 6-10% water, but only absorbed 4-20% water after modification. This due to the siloxane structure surrounding filler. And the results indicate that the introduction of the MAGHA
has no appreciable influence on oil resistance of polysulfide sealants. This new kind multi-alkoxyorganosilane coupling agents with hydroxyl -amine group have the similar effect of modification to the other resins are expected.
The continue work are going on.