Synthesis and characterization of novel acid-sensitive tert-butyl methacrylate and isobutyl methacrylate containing star-shaped polymers

Long, Timothy Edward; Kilian, Lars; Wang, Zhen He; Esker, Alan R.

doi:10.1117/12.446778

Cited by 3 publications

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“…The triggered decomposition of these spherical nanoparticles occurs under acidic conditions to give linear polymer chains. Acid labile cross-linking agents such as 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA – CL1) − or t -butyl ester groups , have been shown to undergo facile cleavage. Many of these pH responsive hydrogels have been used in medical applications, especially for drug delivery systems.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties and Moisture Transport Behavior of Acid-Sensitive Hydrogels

Bhaladhare

Kim

Carter

2019

ACS Appl. Polym. Mater.

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Thin hydrogel films containing the acid sensitive cross-linker 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA) were synthesized as part of a larger project to create protective layers against chemical and biological (CB) threats. In order to operate efficiently as fabric coatings, the mechanical and moisture vapor transport properties of these materials must be understood. The hydrogels were composed primarily of poly(ethylene glycol) dimethacrylate (PEGDMA) and 2-hydroxyethyl methacrylate (HEMA) and were prepared by free radical cross-linking polymerization. The influence of different compositions of DHDMA, PEGDMA, and HEMA on the moisture vapor transmission rate (MVTR), mechanical properties, and swelling properties of PEGDMA/DHDMA/HEMA copolymer hydrogels has been investigated. The characterization by Fourier transform infrared (FTIR) spectroscopy confirmed the presence of all monomers used in the gel structure. The hydrogels showed high MVTR, which are comparable to the widely accepted breathable membrane of Gore-Tex fabric and expanded polytetrafluoroethylene (ePTFE). The swelling data indicated that the equilibrium water content depends on the composition of hydrogels. It was found that addition of HEMA into the PEGDMA-based hydrogels was very helpful to improve the swelling properties but decrease in water contact angle. Rheological study of hydrogels showed that the hydrogels are very stiff and their stiffness increases with increasing PEGDMA content in the hydrogels.

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Section: Introductionmentioning

confidence: 99%

Mechanical Properties and Moisture Transport Behavior of Acid-Sensitive Hydrogels

Bhaladhare

Kim

Carter

2019

ACS Appl. Polym. Mater.

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“…Tertiary esters present in divinyl cross-linked networks have also been shown to undergo facile cleavage reactions. For example, 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA), an acid labile cross-linking reagent, has been effectively used by researchers to synthesize acid-cleavable polymer networks 7 and cleavable cores for star polymers. , Poly(2,5-dimethyl-2,5-hexanediol dimethacrylate) (PDHDMA) networks have also attracted attention as positive photoresists in microlithography , because of the highly acid-labile nature of DHDMA.…”

Section: Introductionmentioning

confidence: 99%

Triggered Decomposition of Polymeric Nanoparticles

Jhaveri

Carter

2007

Macromolecules

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Acid-catalyzed hydrolysis of 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA)-containing nanoparticles has been carried out to bring about topological reorganization from spherical macromolecular crosslinked particles to linear polymer. The reactive cross-linked poly(methyl methacrylate)-based (x-PMMA) nanoparticles have been prepared via aqueous emulsion techniques where the size of the particles depends upon the type of emulsion polymerization employed, surfactant-free or surfactant-based. Potassium persulfate has been employed as the water-soluble initiator and sodium dodecyl sulfate as the surfactant. Because of the acid-sensitive nature of the tertiary ester groups of the 2,5-dimethyl-2,5-hexanediol dimethacrylate within the cross-linked nanoparticles, they can be easily cleaved into their linear polymer chain composition under acidic conditions. The particles were degraded by heating in dioxane in the presence of p-toluenesulfonic acid at 100 °C for 12 h. The cleavage of the cross-linked nanoparticles was observed by the correlation and size distribution plots obtained using dynamic light scattering. The particles and the acid cleaved, linear polymer residue were characterized using scanning electron microscopy (SEM), solubility tests, and gel permeation chromatography.

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Synthesis and cleavage of core‐labile poly(alkyl methacrylate) star polymers

Kilian

Wang

Long

2003

J. Polym. Sci. A Polym. Chem.

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Core‐cleavable star polymers were synthesized by the coupling of living anionic poly(alkyl methacrylate) arms with either dicumyl alcohol dimethacrylate (DCDMA) or 2,5‐dimethyl‐2,5‐hexanediol dimethacrylate (DHDMA). This synthetic methodology led to the formation of star polymers that exhibited high molecular weights and relatively narrow molecular weight distributions. The labile tertiary alkyl esters in the DCDMA and DHDMA star polymer cores were readily hydrolyzed under acidic conditions. High‐molecular‐weight star polymer cleavage led to well‐defined arm polymers with lower molecular weights. Hydrolysis was confirmed via 1H NMR spectroscopy and gel permeation chromatography. Thermogravimetric analysis (TGA) of the star polymers demonstrated that the DCDMA and DHDMA star polymer cores also thermally degraded in the absence of acid catalysts at 185 and 220 °C, respectively, and the core‐cleavage temperatures were independent of the arm polymer composition. The difference in the core‐degradation temperatures was attributed to the increased reactivity of the DCDMA‐derived cores. TGA/mass spectrometry detected the evolution of the diene byproduct of the core degradation and confirmed the proposed degradation mechanism. The DCDMA monomer exhibited a higher degradation rate than DHDMA under identical reaction conditions because of the additional resonance stabilization of the liberated byproduct, which made it a more responsive cleavable coupling monomer than DHDMA. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3083–3093, 2003

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Synthesis and characterization of novel acid-sensitive tert-butyl methacrylate and isobutyl methacrylate containing star-shaped polymers

Cited by 3 publications

References 0 publications

Mechanical Properties and Moisture Transport Behavior of Acid-Sensitive Hydrogels

Mechanical Properties and Moisture Transport Behavior of Acid-Sensitive Hydrogels

Triggered Decomposition of Polymeric Nanoparticles

Synthesis and cleavage of core‐labile poly(alkyl methacrylate) star polymers

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