New synthetic Ni-talc was used as filler in the synthesis of polyurethane (PU) nanocomposites by in situ polymerization and to emphasize the contribution of the new material compared with natural talc. Good dispersion of Ni-talc was supported by homogeneous green coloration observed in the polymer matrix. X-ray diffraction (XRD) analyses indicate the intercalation of polymeric matrix into the filler layers by the increase in d 001 -spacing value of the Ni-talc for the nanocomposites when compared to the pristine filler. The nanocomposites obtained with synthetic talc showed an improvement in the crystallization temperature and in thermal stability when compared to pure PU and the composite obtained with natural talc. The young modulus of PU/talc materials containing both Ni-talc and natural talc were slight higher than pure PU. As shown by scanning electron microscope (SEM), Ni-talc fillers were well dispersed into the polymeric matrix probably due to the good compatibility of both phases filler/polymer mainly achieved by the filler OH interaction with the urethane group of the polymeric chain.

This work presents the syntheses of PU nanocomposites, by in situ polymerization technique, using different synthetic talcs as inorganic filler. The fillers were obtained from two different hydrothermal treatments and composition (talc-Mg and talc-Ni). For nanocomposites syntheses 3% w/w of synthetic talc were added related to the weight of pure polymer. Samples were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) to understand the influence of the fillers syntheses and composition in morphological and thermal properties of the obtained nanocomposites. When talc-Ni was used as filler, the resulting nanocomposite was intercalated while with talc-Mg was exfoliated into the polyurethane matrix. Both fillers have increased the thermal properties of the polymer, but the exfoliated nanocomposite provided higher thermal stability.

Two new synthetic silico-metallic mineral particles like TOT-TOT swelling interstratified (SSMMP) produced with distinct hydrothermal processes (talc 7 h/315°C and talc 24 h/205°C) were used to synthesize polyurethane nanocomposites by in situ polymerization technique. These fillers were added in a range of 0.5-5 wt% related to the mass of the pure polymer. The dispersion and interaction between the fillers and the polymeric matrix were evaluated by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The X-ray analysis indicated that the synthetic SSMMP are well dispersed/or exfoliated into the polymer matrix. The high surface area of the synthetic SSMMP was significant for the increase in the crystallinity and thermal properties of the nanocomposites. In the case of Young's modulus, for nanocomposites PU/SSMMP 24 h and the pristine PU, a similar behavior was observed. However, for the nanocomposites PU/SSMMP 7 h, an increase in the Younǵs modulus values until 3 % of filler addition when compared to pure PU was noticed. The creep-recovery test showed that both SSMMP behave as a mechanical restraint of the polyurethane chains. The results evidenced the importance of the SSMMP syntheses conditions to obtain nanocomposites with desired properties.

Waterborne polyurethane (WPU) nanocomposites were produced utilizing synthetic talc in gel form in order to improve its physical-chemical properties. Synthetic talc manufactured in nano-gel form are interesting because their interaction with water occurs through hydrogen bonding favoring fillers dispersion within the WPU matrix. WPUs are environmental friendly materials because no organic solvents are used in its production. The nanocomposites obtained with the three synthetic talc nano-gel fillers presented a good dispersion even when higher amounts of fillers were added, as seen by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and atomic force microscopy analyses. The addition of synthetic talcs improved WPU nanocomposites mechanical properties. Storage and loss modulus results proved fillers incorporation into the WPU matrix corroborating with Fourier transform infrared spectroscopy results. Results demonstrated that synthetic talcs in nano-gel form are interesting to obtain WPU nanocomposites with superior mechanical properties.

No abstract

No abstract

No abstract

Polyurethane (PU) nanocomposites filled with inorganic particles, aiming at the improvement of mechanical and thermal properties, are well known. Unlike previous work we describe here the combination of two fillers, synthetic talc (silico-metallic mineral particles-SSMMP) with distinct hydrothermal processes (SSMMP 7 h and 24 h) and organically-modified commercial clay (SPR), aiming towards development of new polyurethane ternary nanocomposites by in situ polymerisation. Fillers were added 3 wt.% of the mass of pristine polymer, with a ranging of weight proportions (75:25/25:75) of SSMMP and SPR. Results were compared to those for nanocomposites containing pure SSMMP and SPR fillers. Dispersion degrees and filler interactions with the polyurethane matrix were followed by FTIR, XRD, SEM, TEM and AFM techniques. Results showed that the fillers presented a good dispersion and were exfoliated/ well dispersed in the polyurethane matrix. Thermal and mechanical properties of nanocomposites were evaluated in comparison to the binary nanocomposites (PU/SSMMP 7 h, PU/SSMMP 24 h and PU/ SPR). All nanocomposites presented superior values of Young's modulus to that of pristine PU. Results evidenced that the blend of SSMMP and SPR fillers is an interesting strategy to improve thermal and mechanical properties of nanocomposites.