Biodegradable and biocompatible inorganic-organic hybrid materials: 2. Dynamic mechanical properties, structure and morphology

Tian, Dong; Blacher, Silvia; Dubois, Philippe; Jérôme, Robert

doi:10.1016/s0032-3861(97)00343-1

Cited by 55 publications

(37 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The weight composition of the PCL-silica hybrid materials prepared in this study is close to 50%. The cocontinuity of the PCL and silica phases has been previously reported in this composition range [8]. The average distance between the constitutive components (characteristic length) is of a few nanometers, and increases with the acid content except for the lower HCl:TEOS ratio (sample a).…”

Section: Small-angle X-ray Scattering (Saxs)supporting

confidence: 69%

“…It also appears that the fractal dimension increases with acid content (Table 2), which suggests that more open structures are formed when the acid content is decreased. As previously pointed out, the hydrogen bonding between PCL and silica must have a retardation effect on their phase separation [8] and thus perturb the aggregation of the inorganic constitutive component, which can account for a fractal dimension smaller than expected for neat TEOS under acidic conditions.…”

Section: Small-angle X-ray Scattering (Saxs)mentioning

confidence: 89%

See 1 more Smart Citation

Biodegradable and biocompatible inorganic–organic hybrid materials: 4. Effect of acid content and water content on the incorporation of aliphatic polyesters into silica by the sol-gel process

Tian

Blacher

Jérôme

1999

Polymer

Self Cite

View full text Add to dashboard Cite

The extent of poly -caprolactone (PCL) incorporation into silica networks prepared by the sol-gel process depends on the HCl:tetraethoxysilane (TEOS) molar ratio and the H 2 O:TEOS molar ratio, as well. The PCL incorporation increases with the concentration of the acid used as the catalyst. Dynamic mechanical analysis (DMA) indicates that increasing the acid concentration or decreasing the water content results in a higher glass transition temperature for the organic component in the hybrid materials, whereas the modulus does not change significantly. Small-angle X-ray scattering (SAXS) data agree with a nanoscopic phase separation of the two constitutive components: the organic polymer and the silica network. The characteristic length of this two-phase structure increases with acid content (except for the lower HCl:TEOS molar ratio of 0.05) and with water content (except for the higher H 2 O:TEOS molar ratio of 2.0). The structure of the PCL/SiO 2 interface is mass fractal and the structure is more open when the acid content is lower or the water content higher.

show abstract

Section: Small-angle X-ray Scattering (Saxs)supporting

confidence: 69%

Section: Small-angle X-ray Scattering (Saxs)mentioning

confidence: 89%

Biodegradable and biocompatible inorganic–organic hybrid materials: 4. Effect of acid content and water content on the incorporation of aliphatic polyesters into silica by the sol-gel process

Tian

Blacher

Jérôme

1999

Polymer

Self Cite

View full text Add to dashboard Cite

show abstract

“…[12][13][14][15][16][17][18][19][20] The sol-gel approach consists in low temperature hydrolysis and condensation reactions that yield controlled composition nanostructured organicinorganic materials.…”

Section: Introductionmentioning

confidence: 99%

Study of Organic Phase Mobility in Nanocomposite Organic‐Inorganic Coatings

Ceccorulli

Zini

Scandola

2006

Macro Chemistry & Physics

View full text Add to dashboard Cite

Summary: Organic‐inorganic hybrids synthesized by a dual photopolymerization and condensation process from (i) two organic precursors, either poly(ethylene glycol) α,ω diacrylate ($\overline M _{\rm w}$ = 600) (PEGDA) or bisphenol‐A‐ethoxylate(15EO/phenol)‐dimethacrylate (BEMA), (ii) the organic‐inorganic bridging monomer (methacryloyl‐oxypropyl‐trimethoxysilane, (MEMO)) and (iii) the inorganic precursor tetraethoxysilane (TEOS) were investigated by differential scanning calorimetry (DSC) and dynamic mechanical spectroscopy (DMTA). It is found that progressive formation of the crosslinked network during the different steps of hybrid production results in changes of molecular mobility that show up in changes of the glass transition of the organic phase. While moving from the organic precursor to the final hybrid through the subsequent photopolymerization and condensation reactions, the transition is seen to broaden, decrease in intensity and shift to higher temperature. Excellent agreement of DSC and DMTA results is obtained. Dynamic mechanical analysis of the hybrids coated on PET film (coating thickness 10 and 40 µm) show an additional up‐shift of Tg, more marked in the case of the thinner hybrid coating. This result is attributed to molecular interactions at the substrate‐coating interface that locally hinder molecular mobility. The consequent increase of Tg is more evident when the coating layer is thin. The results show the potential of the DMTA technique in coating‐polymer substrate adhesion studies. Finally, the relaxation spectrum of the hybrids is sensitive to humidity absorbed from the environment and reversibly changes in absorption‐desorption cycles.

show abstract

“…[6] A number of different organic polymers have been investigated as constituents of the ceramer organic phase. [6][7][8][9] The preferred procedure for the synthesis is the sol-gel process. It is based on two steps involving hydrolysis and condensation reactions starting from metal alkoxides.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of Hybrid Nanocomposites Coated on LDPE

Mazzocchetti¹,

Scandola²,

Amerio³

et al. 2006

Macro Chemistry & Physics

View full text Add to dashboard Cite

Summary: Hybrid organic‐inorganic nanocomposites containing hyperbranched structures were prepared through a dual‐curing process, which involves photopolymerization and condensation alkoxysilane groups. In particular, an oligomer containing PEO units and α,ω‐methacrylate groups was used together with a HBP bearing acrylic groups as the organic phase precursors. MEMO, as the organic‐inorganic linker, and TEOS, as inorganic phase precursor, were also employed. The kinetics of both photopolymerization and condensation reactions were investigated by double bond conversion analysis (via FT‐IR) and weight loss determination, respectively. The mobility of the organic phase was studied by means of DSC and DMTA and correlated with hybrid composition. TEM analyses performed on microtomed film slices indicated the formation of nanoscale silica domains. Hybrids were coated onto an LDPE film previously subjected to a plasma treatment, and substrate‐coating interfacial adhesion was investigated through stress‐strain and DMTA experiments.Reaction scheme showing the insertion of furanic units in copolyester chains by ester interchange reaction.magnified imageReaction scheme showing the insertion of furanic units in copolyester chains by ester interchange reaction.

show abstract

Biodegradable and biocompatible inorganic-organic hybrid materials: 2. Dynamic mechanical properties, structure and morphology

Cited by 55 publications

References 15 publications

Biodegradable and biocompatible inorganic–organic hybrid materials: 4. Effect of acid content and water content on the incorporation of aliphatic polyesters into silica by the sol-gel process

Biodegradable and biocompatible inorganic–organic hybrid materials: 4. Effect of acid content and water content on the incorporation of aliphatic polyesters into silica by the sol-gel process

Study of Organic Phase Mobility in Nanocomposite Organic‐Inorganic Coatings

Preparation and Characterization of Hybrid Nanocomposites Coated on LDPE

Contact Info

Product

Resources

About