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Today's new push is "low temperature ring opening polymerization of propylene oxide catalyzed by DMC", by Li Shupeng, Yu Haiming, etc.
abstract
The prepolymer of silicone modified polyurethane sealant was synthesized by using glycol adipate, toluene-2,4 diisocyanate, diol and hydroxy silicone oil as main raw materials. The structure and physical properties of the prepolymer were characterized by IR. The results show that the prepolymer of polyurethane sealant has little effect on the mechanical properties of sealant due to its long storage time and little effect on the ambient temperature and air humidity.
Keywords: polyurethane prepolymer; organosilicon modification; structure characterization; physical properties
Trial section:
Polyurethane sealant has good adhesion to many materials, and has the advantages of wear resistance, cold resistance, oil resistance, good elasticity, vibration resistance and so on [1]. In recent years, polyurethane sealant has been widely used in the direct bonding and sealing of windshield and rear window, as well as the body, interior parts and maintenance. In addition, with the development of the construction market, the sealing construction of metal curtain walls, airports, roads and bridges, tunnel joints, etc. has also expanded the demand for polyurethane sealant [2]. The structure of polyurethane is composed of soft segment and hard segment by block, graft or interpenetrating network. The soft segment is usually polyether or polyester, which endows polyurethane with flexibility and toughness. The hard segment is usually the polycondensation of diisocyanate and small molecule diol or diamine (as chain extender), which endows polyurethane with strength and rigidity. Organosilicon material is a polymer synthetic material containing silicon element in molecular structure. The main chain is a stable framework composed of Si-O-Si chain alternately. Organic groups are connected with silicon atoms to form side groups. It has good heat resistance
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