Synthesis, morphology, and viscoelastic properties of cyanate ester/polyhedral oligomeric silsesquioxane nanocomposites

Liang, Kaiwen; Toghiani, Hossein; Li, Guizhi; Pittman, Charles U.

doi:10.1002/pola.20861

Cited by 95 publications

(85 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No sharp and narrow peaks were observed due to the presence of a meta and para isomeric mixture of OMPS [30,31]. Further, the peak at 5.3° is absent in the diffraction patterns of the hybrid OMPS/epoxy-DDM cured systems.…”

Section: Morphological Studiesmentioning

confidence: 99%

Synthesis and Characterization of a POSS-Maleimide Precursor for Hybrid Nanocomposites

Jothibasu

Premkumar

Alagar

et al. 2007

High Performance Polymers

View full text Add to dashboard Cite

Epoxy-POSS based hybrid nanocomposites are prepared by in situ polymerization of a homogeneous blend of the diglycidylether of bisphenol-A (DGEBA) and 4,4'-diaminodiphenylmethane (DDM) in the presence of octa(maleimidophenyl)silsesquioxane (OMPS). The reaction of a maleimido-functionalised POSS cube with the epoxy resin is studied by Fourier transform infrared (FTIR) analysis and the formation of nanocomposites is confirmed by wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). Dynamic mechanical analysis (DMA) studies indicate that the crosslinking structures of the nanocomposite networks are predominantly formed 2 between the terminal maleimide double bonds and the amino groups of DDM through a Michael addition reaction to form an aspartimide. The values of the glass transition temperatures (T g ) decrease with increasing POSS-maleimide content and this is likely to be due to the inclusion of POSS cages into the system and consequent increase in free volume. The dynamic thermal stability of the cured polymers is increased by increasing the POSS content in the hybrid epoxy matrices as evidenced from thermogravimetric analysis (TGA) data.

show abstract

Section: Morphological Studiesmentioning

confidence: 99%

Synthesis and Characterization of a POSS-Maleimide Precursor for Hybrid Nanocomposites

Jothibasu

Premkumar

Alagar

et al. 2007

High Performance Polymers

View full text Add to dashboard Cite

show abstract

“…21 In contrast, fully condensed polyhedral oligomeric silsesquioxane (POSS) molecules (Figure 1), such as a closed cage POSS ( Figure 1A) (R 8 T 8 , where T is a silsesquioxane unit and R is alkyl), are nonamphiphilic. 23,24 Given both the theoretical and experimental interest in POSS as a versatile hybrid organic-inorganic material with a core-shell structure, [25][26][27][28][29][30][31][32] and the fact that open cage [33][34][35][36] trisilanol-POSS structures ( Figure 1B) are amphiphilic (T 7 R 7 (OH) 3 , where R is variable), combining POSS with PEG could lead to interesting amphiphiles.…”

Section: Introductionmentioning

confidence: 99%

Telechelic Poly(ethylene glycol)−POSS Amphiphiles at the Air/Water Interface

Lee

Deng

et al. 2007

Macromolecules

View full text Add to dashboard Cite

Combining two non-surface-active building blocks, oligomeric poly(ethylene glycol) (PEG) and a completely hydrophobic polyhedral oligomeric silsesquioxane (POSS) cage, creates amphiphilic telechelic polymers (POSS-PEG-POSS), which exhibit surface activity at the air/water (A/W) interface. POSS moieties serve as the hydrophobic groups for hydrophilic PEG chains of different number-average molar mass (1, 2, 3.4, 8, and 10 kg mol -1 ). For short PEG chains (1, 2, and 3.4 kg mol -1 ), insoluble monolayers form, whereas POSS end groups were not sufficiently hydrophobic to keep higher molar mass hydrophilic PEG blocks (8 and 10 kg mol -1 ) at the A/W interface. Thermodynamic analyses of the 1, 2, and 3.4 kg mol -1 POSS-PEG-POSS via surface pressurearea per monomer isotherms indicate that the POSS end groups reside at the A/W interface and that the PEG chains are squeezed into the subphase with increasing surface pressure. This conclusion is supported by X-ray reflectivity studies on Y-type Langmuir-Blodgett multilayer films which reveal a double-layer structure with a double-layer spacing of about 3.52 nm. These findings provide a strategy for producing new surface active species from non-surface-active precursors.

show abstract

“…These include everything from polyhedral oligomeric silsesquioxane (POSS), [23][24][25] at around 1 nm, through functionalized nanoclay particles at 1 x 100…”

Section: Introductionmentioning

confidence: 99%

A New Silicon-Containing Bis(cyanate) Ester Resin with Improved Thermal Oxidation and Moisture Resistance

et al. 2006

View full text Add to dashboard Cite

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)2. REPORT TYPE 3. DATES COVERED (From -To) SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)Air Force Research Laboratory (AFMC) AFRL/PRS SPONSOR/MONITOR'S Pollux Drive NUMBER(S)Edwards AFB CA 93524-7048 AFRL-PR-ED-JA-2006-178 DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release; distribution unlimited (AFRL-ERS-PAS-2006-132) SUPPLEMENTARY NOTESTo be published in the ACS journal Macromolecules. AbstractA new cyanate ester monomer was prepared from bis(4-cyanatophenyl)-dimethylsilane (SiMCy) and fully characterized by analytical and spectroscopic techniques. The monomer was found to have a melting point about 20 °c lower than that of the commercial bis(4-cyanatophenyl)dimethylmethane (BADCy) with similar melt viscosity, curing kinetics, and post-cure glass transition temperature. Analysis of the single-crystal molecular structure by x-ray diffraction showed that intermolecular packing was dominated by weak hydrogen-bonding attractions between the aromatic rings and the -OCN nitrogen atoms. In contrast, the packing interactions found in BADCy are dominated by dipole-dipole interactions of the OCN groups. These differences may explain the 50% reduction in moisture uptake observed in SiMCy as compared to BADCy during exposure to boiling water. In addition, thermogravimetric analysis revealed that SiMCy exhibited a significantly higher char yield in air than BADCy, presumably due to the formation of silicates at high temperature. The combination of improved thermooxidative stability and reduced moisture absorption without significant loss in ease of processing or mechanical properties makes SiMCy an important potential "drop in" replacement for BADCy, and demonstrates the power of the molecular level approach to designing new hightemperature polymer materials. SUBJECT TERMS SECURITY CLASSIFICATION OF:17 Abstract.A new cyanate ester monomer was prepared from bis(4-cyanatophenyl)-dimethylsilane (SiMCy) and fully characterized by analytical and spectroscopic techniques. The monomer was found to have a melting point about 20 °C lower than that ...

show abstract

Synthesis, morphology, and viscoelastic properties of cyanate ester/polyhedral oligomeric silsesquioxane nanocomposites

Cited by 95 publications

References 74 publications

Synthesis and Characterization of a POSS-Maleimide Precursor for Hybrid Nanocomposites

Synthesis and Characterization of a POSS-Maleimide Precursor for Hybrid Nanocomposites

Telechelic Poly(ethylene glycol)−POSS Amphiphiles at the Air/Water Interface

A New Silicon-Containing Bis(cyanate) Ester Resin with Improved Thermal Oxidation and Moisture Resistance

Contact Info

Product

Resources

About