One trend for low dielectric materials is to reach low dielectric constant values at as low porosity as possible. In this work, a lamellar porous material was prepared by spin-coating of poly(vinyl alcohol) (PVA)/manganese dioxide (MnO2) nanosheet composited film, followed by cross-linking of PVA and removing nanosheets. FTIR, XRD and TGA measurement results demonstrate that the templates were almost completely removed. SEM image shows that the etched PVA film has a lamellar porous structure. Dielectric test results indicate that at the porosity of only 17.5%, the dielectric constant of porous PVA is reduced to approximately half that of neat cross-linked PVA. The serial model shows a good consistence with experimental dielectric constant value. This explains well the high efficiency of lamellar porous structure in reducing dielectric constant.

Low dielectric materials show great application potential in future microelectronic industry. In this study, benzocyclobutene-functionalized polycarbosilane derived block copolymer, poly(carbosilane-b-lactide), was synthesized via sequential anionic polymerization of silacyclobutene and ring-opening polymerization of lactide. The block copolymer revealed microphase-separation behavior to form a well-defined morphology. Simultaneously, the sacrifice of polylactide blocks by thermal decomposition and thermally-induced reaction of benzocyclobutene produces cross-linked nanoporous polycarbosilane (PBCS). The dielectric constant of this nanoporous material reaches to around 2.1.

Although general porous materials have a low dielectric constant, their uncontrollable opened porous structure results in high dielectric loss and poor barrier properties, thus limiting their application as interconnect dielectrics. In this study, polymeric nanoporous materials with well-controlled closed pores were prepared by incorporating polystyrene (PS) hollow nanoparticles into polyethylene (PE/HoPS). SEM images suggested a closed porous structure for PE/HoPS. In order to show the effect of the porous structure on dielectric properties, nanoporous materials with an opened or uncontrollable porous structure were prepared by etching SiO2/PE or PE/PS@SiO2 composites. PE/HoPSs composites showed an apparently lower dielectric constant and loss compared with the opened porous PE, demonstrating the advantages of a closed porous structure upon enhancing low-dielectric performance. The low dielectric performance of the PE/HoPS composites is linked with high water resistance owing to their closed porous characteristics. When incorporating 15.3 wt% HoPS (porosity: ∼6.9%), the dielectric constant reached 2.08. This value is lower than that calculated from the serial model. Our work revealed that the incorporation of HoPS not only reduces the porosity, but also alters the intrinsic properties of PE, as a result, leading to a greatly reduced dielectric constant.

Double-walled Al–P–Si hybrid decomposable nanorods, which have a silica coated aluminum phosphonate nanostructure, were in situ prepared by thorough but ordered reconstruction of montmorillonite. The reconstruction was facilely performed through hydrothermal reaction of montmorillonite with diphenyl phosphoric acid. The formation process of nanorods involves the decomposition of montmorillonite, the repolymerization to generate aluminum phosphonates, the assembly via π–π stacking interactions to form a 1D nanostructure, and the coating of silica on aluminum phosphonate nanorods. Interestingly, it was found that only layered silicates exhibited such reconstruction into hybrid nanorods. The decomposition of the nano-sized sandwich structure may lead to highly reactive Si–O tetrahedra and a synergistic reaction process. The nanorods showed decomposition around 400 °C, producing nanoparticles mainly composed of aluminum silicates. The fire property test showed that epoxy/Al–Si–P hybrid nanorod nanocomposites exhibited outstanding flame retardant performance. One possible explanation for this is that nano-sized particles resulting from decomposition easily migrated to the surface of epoxy resins, consequently forming protective layers.

Catalytic sequential hydroboration of decaborane for the synthesis of poly(organodecaborane), with decaborane in the mainchain, is reported for the first time. Under a platinum catalytic system, poly(6-hexenyldecaborane) and poly(6-norbornenyldecaborane) are obtained with well-defined structures and a moderate yield. Thermogravimetric analysis demonstrates that the char yields are 73% and 82%, respectively.

A novel silicon-/phosphorus hybrid (SDPS) was synthesized by a condensation polymerization of diphenylhydroxysilane and spirocyclic pentaerythritol di(phosphate monochloride). The use of SDPS and the cooperative use of SDPS with P–N hybrid in flame retardant epoxy resin (EP) were investigated. Limiting oxygen index and cone calorimeter tests showed that the loading of SDPS and the cooperative use of SDPS and P–N hybrid in EP provided enhanced fire resistance. TGA, TG-FTIR and SEM measurements revealed that the enhancement in fire resistance was arising from the formation of a compact honeycomb carbonaceous structure hybridized by silica, the good char forming ability and the inhibition of flammable gas release. Further analysis from Raman spectra revealed that the compact carbonaceous layer may be originated from an increase in ordering of amorphous carbonaceous layer.

A series of benzocyclobutene-carbosilane thermosets derived from benzocyclobutene-containing oligomeric silylenephenylene (PBSEPs) were synthesized. DSC analysis results demonstrated that the reaction of PBSEPs presumably took place within the temperature range of 200–350 °C. FT-IR, 1H NMR and 13C NMR results demonstrated that this exothermic reaction was attributed to a [4 + 2] cycloaddition. DSC results further revealed that benzocylcobutene linked with silylene exhibited lower exothermic temperature compared with that linked with Si(CH3)2. Chemical simulation results attributed the lower temperature to lower steric hindrance and greater activity. DSC and TGA analysis of the thermosets showed high Tg and thermostability, and good pyrolysis yield.

New aluminum–organophosphorus hybrid nanorods (AOPH-NR) have been prepared by reacting aluminum hydroxide (ATH) with dibenzylphosphinic acid (DBPA) with aluminum hydroxide (ATH) and used to prepare nanocomposites with epoxy resin. In order to determine the structure–property relationship of these composites, several other phosphinic acids of the general formula (R(CH2)n)2POOH (R = ester, allyl, nitrile, n = 1 or 2), and corresponding AOPHs were synthesized. FTIR, Raman, TGA, and XRD examinations showed that only AOPH-NR possesses a highly hybrid structure and high thermostability. SEM and TEM confirmed the nanorod morphology of AOPH-NR. The formation mechanism can be described as a decomposing–reforming process. This characteristic causes AOPH-NR to exhibit superior properties. Limiting oxygen index (LOI) determination and cone calorimeter analysis showed that the incorporation of only 4.25 wt% AOPH-NR remarkably improved the LOI value to as much as 28.0 and led to a 23% reduction in peak heat release rate (PHRR). Dynamic mechanical analysis (DMA) indicated that the mechanical properties of epoxy resin were also improved by incorporating AOPH-NR. In this way, the aluminum–organophosphorus hybridization via reacting ATH with specific organophosphinic acids shows promise as a means of improving flame retardancy and mechanical properties simultaneously. The thermal and anti-flaming properties of composites, combined with the properties of AOPHs, allowed us to discover the important role that the release and migration of phosphorus species plays in fire-retarding materials. This provides a new insight into the design of high-performance flame retardants.

Recently, much effort has been directed toward fabrication of metal-organophosphorus hybrids with microporous, fibered, layered, and open structures to obtain desired mechanical, optical, electric, and catalytic properties. In this work, aluminum–phosphorus hybrid nanorods (APHNRs) with regular morphology were prepared by a template-free hydrothermal reaction of aluminum hydroxide with diphenylphosphinic acid (DPPA). Structure characterization of APHNRs by Fourier transform infrared spectroscopy, laser Raman spectroscopy, and X-ray diffraction demonstrate a structure with aluminophosphate main chains and phenyl pendant groups, which enable self-assembly into nanorods. The reaction conditions and the structures of phosphinic acids appear to have a significant impact on the morphology and size of nanorods. Moreover, the evolution of morphology and structure assembly during the forming process of APHNRs, as monitored by SEM and XRD, reveal a decomposition-assembly propagation process where the driving force of assembly is attributed to π–π stacking interactions between phenyl pendant groups. APHNRs show a significant increase in light emission relative to pure DPPA due to their compact structure resulting from the π–π stacking interaction. Detailed investigation revealed that photoluminescence was remarkably amplified by enhancing the compactness of APHNRs.

A benzocyclobuten-4-yl acrylate (1) monomer was prepared by esterification of 4-hydroxybenzocyclobutene with acryloyl chloride. The radical homopolymerization of 1 and copolymerization of 1 with styrene or n-butyl acrylate were carried out to produce linear polymers 2a, 2b and 2c. Heating of these linear polymers under thermal initiation gave corresponding cross-linked polymers 3a, 3b and 3c. The ring-opening reaction in the cross-linking process was confirmed by on-line infrared spectra. Differential scanning calorimetry showed that the glass transition temperatures of linear polymers 2a and 2b were 83.2°C and 68.1°C, respectively. Thermogravimetric analysis of the cross-linked polymers showed that they all exhibited good thermal stability.

Although general porous materials have a low dielectric constant, their uncontrollable opened porous structure results in high dielectric loss and poor barrier properties, thus limiting their application as interconnect dielectrics. In this study, polymeric nanoporous materials with well-controlled closed pores were prepared by incorporating polystyrene (PS) hollow nanoparticles into polyethylene (PE/HoPS). SEM images suggested a closed porous structure for PE/HoPS. In order to show the effect of the porous structure on dielectric properties, nanoporous materials with an opened or uncontrollable porous structure were prepared by etching SiO2/PE or PE/PS@SiO2 composites. PE/HoPSs composites showed an apparently lower dielectric constant and loss compared with the opened porous PE, demonstrating the advantages of a closed porous structure upon enhancing low-dielectric performance. The low dielectric performance of the PE/HoPS composites is linked with high water resistance owing to their closed porous characteristics. When incorporating 15.3 wt% HoPS (porosity: ∼6.9%), the dielectric constant reached 2.08. This value is lower than that calculated from the serial model. Our work revealed that the incorporation of HoPS not only reduces the porosity, but also alters the intrinsic properties of PE, as a result, leading to a greatly reduced dielectric constant.

Catalytic sequential hydroboration of decaborane for the synthesis of poly(organodecaborane), with decaborane in the mainchain, is reported for the first time. Under a platinum catalytic system, poly(6-hexenyldecaborane) and poly(6-norbornenyldecaborane) are obtained with well-defined structures and a moderate yield. Thermogravimetric analysis demonstrates that the char yields are 73% and 82%, respectively.

New aluminum–organophosphorus hybrid nanorods (AOPH-NR) have been prepared by reacting aluminum hydroxide (ATH) with dibenzylphosphinic acid (DBPA) with aluminum hydroxide (ATH) and used to prepare nanocomposites with epoxy resin. In order to determine the structure–property relationship of these composites, several other phosphinic acids of the general formula (R(CH2)n)2POOH (R = ester, allyl, nitrile, n = 1 or 2), and corresponding AOPHs were synthesized. FTIR, Raman, TGA, and XRD examinations showed that only AOPH-NR possesses a highly hybrid structure and high thermostability. SEM and TEM confirmed the nanorod morphology of AOPH-NR. The formation mechanism can be described as a decomposing–reforming process. This characteristic causes AOPH-NR to exhibit superior properties. Limiting oxygen index (LOI) determination and cone calorimeter analysis showed that the incorporation of only 4.25 wt% AOPH-NR remarkably improved the LOI value to as much as 28.0 and led to a 23% reduction in peak heat release rate (PHRR). Dynamic mechanical analysis (DMA) indicated that the mechanical properties of epoxy resin were also improved by incorporating AOPH-NR. In this way, the aluminum–organophosphorus hybridization via reacting ATH with specific organophosphinic acids shows promise as a means of improving flame retardancy and mechanical properties simultaneously. The thermal and anti-flaming properties of composites, combined with the properties of AOPHs, allowed us to discover the important role that the release and migration of phosphorus species plays in fire-retarding materials. This provides a new insight into the design of high-performance flame retardants.

Double-walled Al–P–Si hybrid decomposable nanorods, which have a silica coated aluminum phosphonate nanostructure, were in situ prepared by thorough but ordered reconstruction of montmorillonite. The reconstruction was facilely performed through hydrothermal reaction of montmorillonite with diphenyl phosphoric acid. The formation process of nanorods involves the decomposition of montmorillonite, the repolymerization to generate aluminum phosphonates, the assembly via π–π stacking interactions to form a 1D nanostructure, and the coating of silica on aluminum phosphonate nanorods. Interestingly, it was found that only layered silicates exhibited such reconstruction into hybrid nanorods. The decomposition of the nano-sized sandwich structure may lead to highly reactive Si–O tetrahedra and a synergistic reaction process. The nanorods showed decomposition around 400 °C, producing nanoparticles mainly composed of aluminum silicates. The fire property test showed that epoxy/Al–Si–P hybrid nanorod nanocomposites exhibited outstanding flame retardant performance. One possible explanation for this is that nano-sized particles resulting from decomposition easily migrated to the surface of epoxy resins, consequently forming protective layers.