m- and p-TMXDI: Two New lsocyanates For The Polyurethane Industry

Arendt, Volker; Logan, Raymond E.; Saxon, Robert

doi:10.1177/0021955x8201800605

Cited by 18 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aromatic isocyanates usually react faster than aliphatic isocyanates . The sterically hindered secondary/tertiary isocyanates exhibit lower reactivities compared to the less-hindered primary NCO group . Our working hypothesis is that isocyanates with appropriate reactivities maintain moderate polycondensation kinetics and is a critical aspect to achieve good barrier properties of the microcapsules.…”

Section: Resultsmentioning

confidence: 99%

“…39 The sterically hindered secondary/tertiary isocyanates exhibit lower reactivities compared to the less-hindered primary NCO group. 40 Our working hypothesis is that isocyanates with appropriate reactivities maintain moderate polycondensation kinetics and is a critical aspect to achieve good barrier properties of the microcapsules. Highly reactive isocyanates trigger fast interfacial polymerization, disrupt the shell formation/growth process due to unfavorable reaction kinetics.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A Robust Oil-in-Oil Emulsion for the Nonaqueous Encapsulation of Hydrophilic Payloads

Katz

Schmitt

et al. 2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Compartmentalized structures widely exist in cellular systems (organelles) and perform essential functions in smart composite materials (microcapsules, vasculatures, and micelles) to provide localized functionality and enhance materials' compatibility. An entirely water-free compartmentalization system is of significant value to the materials community as nonaqueous conditions are critical to packaging microcapsules with water-free hydrophilic payloads while avoiding energy-intensive drying steps. Few nonaqueous encapsulation techniques are known, especially when considering just the scalable processes that operate in batch mode. Herein, we report a robust oil-in-oil Pickering emulsion system that is compatible with nonaqueous interfacial reactions as required for encapsulation of hydrophilic payloads. A major conceptual advance of this work is the notion of the partitioning inhibitor-a chemical agent that greatly reduces the payload's distribution between the emulsion's two phases, thus providing appropriate conditions for emulsion-templated interfacial polymerization. As a specific example, an immiscible hydrocarbon-amine pair of liquids is emulsified by the incorporation of guanidinium chloride (GuHCl) as a partitioning inhibitor into the dispersed phase. Polyisobutylene (PIB) is added into the continuous phase as a viscosity modifier for suitable modification of interfacial polymerization kinetics. The combination of GuHCl and PIB is necessary to yield a robust emulsion with stable morphology for 3 weeks. Shell wall formation was accomplished by interfacial polymerization of isocyanates delivered through the continuous phase and polyamines from the droplet core. Diethylenetriamine (DETA)-loaded microcapsules were isolated in good yield, exhibiting high thermal and chemical stabilities with extended shelf-lives even when dispersed into a reactive epoxy resin. The polyamine phase is compatible with a variety of basic and hydrophilic actives, suggesting that this encapsulation technology is applicable to other hydrophilic payloads such as polyols, aromatic amines, and aromatic heterocyclic bases. Such payloads are important for the development of extended pot or shelf life systems and responsive coatings that report, protect, modify, and heal themselves without intervention.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

A Robust Oil-in-Oil Emulsion for the Nonaqueous Encapsulation of Hydrophilic Payloads

Katz

Schmitt

et al. 2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…New types of aralkyl diisocyanates have been reported by Arendt et al (37). These are m-and p-tetramethylxylene diisocyanates: 41.…”

Section: Ch2=c -C-0-ch2-ch 2 -Nc0mentioning

confidence: 92%

Urethane Coatings

Frisch

KORDOMENOS

1985

ACS Symposium Series

View full text Add to dashboard Cite

show abstract

“…(TMXDI) Two years ago two new, potentially low cost aliphatic isocyanates, now available in pilot plant quan- tities, were introduced to the market [5]. They are p-and m-tetramethyl xylene diisocyanate (TMXDI).…”

Section: Tetramethyl Xylene Diisocyanatementioning

confidence: 99%