Surface modification of calcium sulfate whisker using thiol‐ene click reaction and its application in reinforced silicone rubber

Abstract

The hemihydrate calcium sulfate whisker (HCSW) was modified by γ‐(methacryloxy)propyl trimethoxy silane (KH570) and trimethylolpropane tris(3‐mercaptopropionate) via wet modification and thiol‐ene click reaction, and then the unmodified and modified HCSW were added into α, ω‐dihydroxy polysiloxane (DPS) matrix to prepare silicon rubber composites. After the dual‐surface modification, the surface of HCSW was transformed to hydrophobic, the hydration of whisker was obviously improved, and the whisker dispersed more evenly in the polymer. The mechanical properties, dynamic mechanical properties, and the medium resistance of the silicone rubber composite were compared. The tensile test shows that the silicone rubber shows better mechanical properties after adding the modified whiskers, among which HCSW‐KH570‐SH has the most significant reinforcement effect. Moreover, DPS/HCSW‐KH570‐SH shows the best medium resistance in toluene, gasoline, and water. The addition of modified whiskers can improve the storage modulus of silicone rubber significantly, while DMA and DSC show that the addition of modified whiskers can reduce the glass transition temperature of silicone rubber. The bound rubber indicates that the interface interaction between HCSW‐KH570‐SH and silicone rubber is the best.

Preparation of a High‐Performance Anti‐Aging Polypropylene Composite with Titanium Oxide and Calcium Sulfate Shielding Agents

“…[25][26][27] Because of the small size and large strength of calcium sulfate whisker can play a skeleton role when added to polymer materials, and the mechanical properties of CSW often significantly improve. [28][29][30] At the same time, calcium sulfate whiskers have good compatibility and good interface binding strength, the advantages of ultra-fine inorganic filler and enhanced fiber can be used as efficient functional materials, based on non-toxic characteristics as additives added to PP will not aggravate the harm caused by white pollution. [31][32][33] Previous studies have demonstrated that the use of nano-TiO 2 as a filler significantly impacts the aging performance of PP products.…”

The Use of the Thiol-Ene Addition Click Reaction in the Chemistry of Organosilicon Compounds: An Alternative or a Supplement to the Classical Hydrosilylation?

“…The hydrothiolation reaction for surface modification finds use in the production of new composite materials for catalysis, chromatography [ 153 ], including the capillary columns for enantioselective nano-HPLC [ 154 , 155 ], for improving the strength characteristics of rubbers [ 156 ], and for biomedical purposes in the immobilization of enzymes such as chemotrypsin [ 157 ] and acetyl cholinesterase [ 158 ].…”