Synthesis Of Amphiphilic Copolymers Containing POSS And SBMA For Anti-fogging,Anti-icing,and Anti-aggregation Of Gas Hydrates

Amphiphilic copolymers containing hydrophilic and hydrophobic groups demonstrate unique properties and have potential applications in many areas.Polyhedral oligomeric silsesquioxane(POSS)shows stability and hydrophobicity.Sulfobetaine methacrylate(SBMA)is a kind of zwitterion with positive and negative charges with enhanced hydration.In this work,we designed and prepared the antifogging/anti-icing coatings from amphiphilic block copolymers of polyhedral oligomeric silsesquioxane-poly[2-(dimethylamino)ethyl methacrylate]-b-poly(sulfob--etaine methacrylate)(POSS-PDMAEMA-b-PSBMA)synthesized via atom transfer radical polymerization(ATRP)with a small amount(10%)of ethylene glycol dimethacrylate(EGDMA)via UV-curing.Additionally,amphiphilic random copolymers POSS-P(VCap-co-VP-co-SBMA)were synthesized from vinyl caprolactam(NVCap),vinyl pyrrolidone(NVP)and SBMA via ATRP for application in anti-aggregation of gas hydrates.For antifogging and anti-icing,the block copolymers containing POSS groups were synthesized via ATRP by using POSS-Br as an initiator.It was suggested that PDMAEMA with a lower critical solution temperature and PSBMA with an upper critical solution temperature in the block copolymers facilitated dispersion and absorption of water molecules into the SIPN coatings,fulfilling the enhanced antifogging function.POSS with low surface energy could aggregate on the surface during the processing of preparing coatings.The amphiphilic SIPN coatings exhibited the anti-icing ability with a freezing delay time of more than 2 min,owing to the aggregation of hydrophobic POSS groups and the self-lubricating aqueous layer generated by non-freezable bond water on the surface.For anti-aggregation of gas hydrates,SBMA in the amphiphilic random copolymers POSS-P(VCap-co-VP-co-SBMA)could show the performance of kinetic inhibitors(KHIs)as well as thermodynamic inhibitors,whereas NVCap and NVP could enhance the KHI properties of the copolymers to a certain.The amphiphilic copolymers also displayed the performance of anti-aggregation due to hydrophobic POSS groups that could regulate and control hydrophilic-hydrophobic equilibrium.Meanwhile,the dosage of a thermodynamic inhibitor such as glycol could be reduced by adding the copolymers as a KHI to form compound gas hydrate inhibitors.It was also suggested that the induction time of forming hydrate had no relationship with the molecular weight of the preparied copolymers at-15 ~oC,25%relative humidity.