Silicone Modified Polyesters Vulcanizable at Room Temperature for Anti-corrosion Coatings on Tinplate

Trimethoxysilyl Polyester(TMOS-PET)was prepared via hydrosilylation of trimethylsilane with acryl-terminated polyester.Copolymerization of TMOS-PET with trimethylmethoxysilane,tetramethoxysilane,and/or dimethyldimethoxysilane give silicone modified polyesters(Si-PET)containing=(SiO_(2))=,-(CH_(3)SiO_(3/2))=,and/or-((CH_(3))_(2)SiO)-units.Coatings from Si-PET were formed on tinplate surface via room temperature vulcanization with applicable curing time(the quickest tact free time and completely drying time are 2 h and 15 h,respectively).Mechanical properties,thermal stability,chemical resistance,and anti-corrosion of coatings were detected.Although the flexibility of the coatings were lowered by=(SiO_(2))=and-(CH_(3)SiO_(3/2))=units,adhesion and thermal stability of coatings were both improved.On the contrary,(CH_(3))_(2)SiOunits seem to improve the flexibility,while decrease the adhesive force for less crosslink points.Generally,the silicone modified polyesters act as an effective shielding for tinplate.According to electrochemical impedance spectroscopy(EIS),the electric resistance of coatings(Rc)were improved about 25 times and open circuit potential(OCP)increased about 0.10 V compared to the control.The chemical resistance and anti-corrosion of the coatings were decreased slightly after=(SiO_(2))=and-(CH_(3)SiO_(3/2))=units were added,but they could be greatly improved by-(CH_(3)SiO_(3/2))=units.Specially,after adding-(CH_(3)SiO_(3/2))=units,coatings give doubled Rc,and its OCP is about 0.20 V higher than the control.

Synthesis and Application of Polyurethane Modified Organic Silicone Wet Rubbing Fastness Improver

Polyurethane modified organic silicone was successfully prepared from hydroxyl-terminated polyether modified silicone,toluene-2,4-diisocyanate( TDI), and NaHSO3. The chemical structure of the polyurethane modified organic silicone was characterized by FT-IR and1H-NMR. The polymer film on the cotton surface was investigated by scanning electron microscopy( SEM) and the results showed that a thin polymer film was successfully formed. The FT-IR of treated cotton fabrics indicated that hydroxyl( OH) of cellulose fiber and isocyanate group( NCO)of the polyurethane modified organic silicone has formed covalent cross-linking. X-ray diffraction( XRD) analysis revealed that the crystalline region of treated cotton fabrics wasn't changed. The wet rubbing fastness of treated cotton fabrics was increased by approximately rating 1 on average. There was little change of DE values for the polyurethane modified organic silicone. The softness was improved significantly.