Polyvinylbutyral Based Hybrid Organic/Inorganic Films as a Moisture Barrier Material

Synthesis of Silphenylene-Containing Siloxane Resins Exhibiting Strong Hydrophobicity and High Water Vapor Barriers

The novel phenylenedisilane, 1,4-bis(dimethoxyphenylsilyl)benzene (BDMPD), was successfully synthesized via the reaction between trimethoxyphenylsilane (TMPS) and a Grignard reagent originating from 1,4-dibromobenzene. In comparison to common Grignard reactions, this process was a facile one-pot method. 1H NMR spectroscopy, FT-IR measurements, and elemental analysis confirmed the predicted structure of BDMPD. In addition, vinyl-terminated polysiloxanes containing silphenylene units (VPSSP), which were hydrolytically copolymerized from BDMPD, TMPS, and divinyltetramethyldisiloxane, exhibited excellent thermal stabilities (T10%: 502 °C, Rw%: 76.86 beyond 700 °C) and suitable refractive indices (1.542). Furthermore, water contact angle and water vapor permeability tests confirmed that the fully cured siloxane resins containing VPSSP-based silphenylene units exhibited strong hydrophobicity (water contact angle: 119°) and superior water vapor barrier properties, thereby indicating their potential to serve as strong waterproof coatings for moisture-proof applications or as adhesives for use in immersed equipment.

PVB/ATO Nanocomposites for Glass Coating Applications: Effects of Nanoparticles on the PVB Matrix

Films made of poly(vinyl butyral) (PVB) and antimony-doped tin oxide (ATO) nanoparticles (NPs), both uncoated and surface-modified with an alkoxysilane, were prepared by solution casting at filler volume fractions ranging from 0.08% to 4.5%. The films were characterized by standard techniques including transmission electron microscopy, thermogravimetric analysis and differential scanning calorimetry (DSC). In the polymeric matrix, the primary NPs (diameter ~10 nm) aggregate exhibiting different morphologies depending on the presence of the surface coating. Coated ATO NPs form spherical particles (with a diameter of 300–500 nm), whereas more elongated fractal structures (with a thickness of ~250 nm and length of tens of micrometers) are formed by uncoated NPs. The fraction of the polymer interacting with the NPs is always negligible. In agreement with this finding, DSC data did not reveal any rigid interface and 1H time domain nuclear magnetic resonance (NMR) and fast field-cycling NMR did not show significant differences in polymer dynamics among the different samples. The ultraviolet-visible-near infrared (UV-Vis-NIR) transmittance of the films decreased compared to pure PVB, especially in the NIR range. The solar direct transmittance and the light transmittance were extracted from the spectra according to CEN EN 410/2011 in order to test the performance of our films as plastic layers in laminated glass for glazing.

Polyvinylbutyral-Polyaniline Nanocomposite for High Microwave Absorption Efficiency

A coatable polyvinylbutyral (PVB)-polyaniline (PANI) nanocomposite was designed for high microwave absorption efficiency. The maximum absorption efficiency 88.2 dB GHz/mm was obtained for the PANI nanofiber-loaded PVB (PVBPN) nanocomposite with a large bandwidth, whereas a pristine PANI-containing composite shows 53.5 dB GHz/mm in the frequency range 8.2-18 GHz. The presence of nanoslit pores in PVBPN also helps to achieve a large bandwidth and hence high microwave absorption efficiency. Standard electromagnetic simulation also shows that power absorbed by the PVBPN nanocomposite is high and its ultrathin coating over the dielectric substrate (epoxy) is promising for broadband tuneable reflection loss.

New Water Vapor Barrier Film Based on Lamellar Aliphatic-Monoamine-Bridged Polysilsesquioxane

Siloxane-based hybrid lamellar materials with ordered nanostructure units paralleling to the substrate have been widely used for water vapor barrier. However, it is very difficult to control the orientation of the lamellar units at molecular level. In this Research Article, a new lamellar bridged polysilsesquioxane (BPSQ) film, whose voids between lamellae were filled by pendant alkyl chains in the organic bridge, was prepared via the stoichiometric reaction between 3-glycidoxypropyltrimethoxysilane and aliphatic monoamine at 60 °C without catalyst. Experimental evidence obtained from FT-IR, MS, NMR, and GIXRD techniques suggested that the as-prepared BPSQ films were constructed by lamellar units with disordered orientation. Nonetheless, they possessed satisfactory water vapor barrier performance for potassium dihydrogen phosphate (KDP) and deuterated potassium dihydrogen phosphate (DKDP) optical crystals, and the water vapor transmission rate through BPSQ film with thickness of 25 μm was as low as 20.3 g·m(-2)·d(-1). Those results proved that filling the voids between molecular lamellae with alkyl chains greatly weakened the effect of lamellar unit orientation on the vapor barrier property of BPSQ film.

Outstanding electromagnetic interference shielding effectiveness of polyvinylbutyral–polyaniline nanocomposite film

In this study, we studied the electromagnetic interference (EMI) shielding property of a solution processed polyvinylbutyral–polyaniline nanocomposite (PVBPN) film in the X-band (8.2–12.4 GHz) and Ku-band (12.4–18 GHz) frequency.

A Surlyn/magnesium oxide nanocomposite as an effective water vapor barrier for organic device encapsulation

A novel system of reactive polymer nanocomposites with MgO was developed, which exhibits superior performances as encapsulants for OPV devices.

Reactive interlayer based ultra-low moisture permeable membranes for organic photovoltaic encapsulation

Reactive water vapor barrier materials with zero valent iron and copper nanoparticles for organic device encapsulation.

Stability of molecular layer deposited zincone films: experimental and theoretical exploration

Experimental and theoretical degradation study of MLD grown hybrid inorganic–organic zincone films.