Layered double hydroxides as fillers in poly(l-lactide) nanocomposites, obtained by in situ bulk polymerization

Abstract

SbstractIn this study in situ bulk polymerization of L-lactide filled with layered double hydroxides (LDH) was investigated. Four different LDHs intercalated with two different organic anions (salicylate and sebacate) were synthesized and characterized. After characterization, these synthetic layered compounds were used as fillers in poly(L-lactide) (PLLA) nanocomposites with two different fillers's loadings (1 wt% and 2 wt%). PLLA and PLLA nanocomposites were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet and visible spectroscopy, thermogravimetric analysis (TGA), dynamical mechanical analysis (DMA), flexural testing and differential scanning calorimetry (DSC). The results demonstrated that, compared to PLLA, the nanocomposite containing 1 wt% of Zn/Al salicylate transmitted less UVA and UVB light, while keeping a similar transparency in the visible region. Thermogravimetric analysis revealed that the nanocomposite with 1 wt% of Zn/Al salicylate exhibited the highest thermal stability. In general the flexural and dynamical mechanical properties were reduced in compassion to neat PLLA. DSC results, demonstrated that, compared to PLLA, all the nanocomposites exhibited lower glass transition temperature and melting temperature values.

Rheological properties of low-density polyethylene filled with hydrophobic Co(Ni)-Al layered double hydroxides

“…Polymer nanocomposites (PNC) are materials in which the matrix is a polymer and the filler has at least one dimension of nanometer magnitude, normally smaller than 100 nm [6] . Layered compounds are composed of two dimensional nanosized layers, which are stacked along the basal axis, being ideal for use as fillers in PNC [7] . Normally, hydrophilic layered compounds can become hydrophobic after the intercalation of specific organic anionic species.…”

Thermal and flammability properties influenced by Zn/Al, Co/Al, and Ni/Al layered double hydroxide in low‐density polyethylene nanocomposites

“…To try to overcome this and other problems, organomodified LDHs have recently been proposed as alternative inorganic materials to be used as flame‐retardant (FR) multifunctional fillers in the formulation of polymeric nanocomposite, including as FR . However, LDHs with different metal contents and different organic anions can affect otherwise thermal and flammability properties of nanocomposites.…”

Performance Evaluation of Layered Double Hydroxides Containing Benzotriazole and Nitrogen Oxides as Autonomic Protection Particles against Corrosion

“…The maximum space that a nitrate ion can occupy is 3.80 Å [22]. The inorganic ions may be arranged between layers at different ways: perpendicularly, horizontally, or tilted at an angle [23], which may reduce the space occupied by these ions by some extension. Hence, the interlayer space value of 3.10 Å may be associated with a more compact orientation of nitrate ions, in addition to the presence of nitrite ions which tend to present a smaller spatial diameter.…”