Emulsion and nanocapsules of ternary graft copolymers

Abstract

Alkyne end-tagged poly(ethylene glycol) methyl ether, polystyrene, and poly(tert-butyl acrylate) (denoted as MPEG-C^CH, PS-C^CH, and PtBA-C^CH, respectively) were grafted randomly onto a (PGMA-N 3 ) backbone via "click" chemistry to produce a series of ternary graft copolymers PGMA-g-(MPEG-r-PtBAr-PS). The selective hydrolysis of the PtBA chains into poly(acrylic acid) (PAA) yielded PGMA-g-(MPEG-r-PAA-r-PS). Since MPEG and PAA were soluble in water while PS was soluble in decahydronaphthalene (DN), the graft copolymers were good surfactants for emulsifying DN in water. Various factors affecting the emulsification were examined, including the stirring rate, the copolymer composition, and the concentration. Crosslinking of the PAA chains, which were distributed among MPEG chains in the coronas of the emulsion droplets, with a diamine produced a novel structure -"nanocapsules" bearing partially crosslinked coronas.

Isothermal crystallization kinetics and melting behaviors of poly(butylene terephthalate) and poly(butylene terephthalate‐co‐fumarate) copolymer

“…It can be seen that each curve shows an initial linear portion, and then tends to deviate from Avrami equation. This deviation is mainly attributed to the secondary crystallization, which is caused by the spherulite impingement and perfection of internal spherulite crystallization in the later stage of the crystallization process [36, 39]. From the slope and intercept of the initial linear portion in Fig.…”

Polymeric approach to combat drug-resistant methicillin-resistant Staphylococcus aureus

“…All these polymers exhibited good antimicrobial activity against methicillinresistant S. aureus. The authors concluded this could be used for coating hospital surfaces, gowns and prevents MDR bacteria [74][75][76][77].…”

Crosslinked polymer nanocapsules

“…For examples, Landfester and co‐workers reported that chitosan‐based CPNCs with D h of 100–300 nm measured using DLS can be obtained by miniemulsion polyaddition crosslinking of chitosan with a diepoxide based on the moderate surfactant property of chitosan, and the addition of biocompatible costabilizer into the system can help to reduce the size of CPNCs; recently Cheng and co‐workers also illustrated that chitosan‐based CPNCs with tunable sizes ( D h = 50–400 nm measured using DLS) can also be synthesized by UV‐induced thiol–ene crosslinking of N ‐maleoyl‐functionalized chitosan in miniemulsions using 1,4‐butanediolbis(3‐mercaptopropionate) as the cross‐linker, and these CPNCs exhibited pH‐triggered release behavior due to their acid‐labile β ‐thiopropionate crosslinkages . Synthetic polymer‐based CPNCs have also been prepared using this approach . Liu and co‐workers reported a series of studies of the preparation of CPNCs using amphiphilic block copolymers or grafted copolymers having photo‐crosslinkable PCEMA chains by UV irradiation of emulsion systems .…”