Novel poly(amide-azomethine) nanocomposites reinforced with polyacrylic acid- co -2-acrylamido-2-methylpropanesulfonic acid modified LDH: Synthesis and properties

Shabanian

2018

J Chinese Chemical Soc

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For improving the oxygen and water vapor barrier properties of poly(lactic acid) (PLA), a new series of PLA-based nanocomposite films containing an organoclay (OC) and a hydrogel were prepared via the solvent casting method. The synthesized hydrogel was used in a PLA system combined with and without the reactive organo-modified clay. Montmorillonite and the protonated form of SABO ® STAB UV 94 were used to prepare the OC via an ion-exchange reaction. The modification of silicate layers was investigated by FTIR, XRD, and TGA techniques. The char residue of the OC obtained was 28% lower than that of the neat montmorillonite, which indicated the presence of SABO in the silicate layer structure. In the presence of the OC, the hydrogel showed a synergistic effect to enhance the barrier properties of PLA. The water vapor permeability decreased from 0.243 to 0.224 g/m 2 Á24 hr in PLA/hydrogel-OC nanocomposite containing 3 mass% each of the hydrogel and OC (PSH 6) compared to the neat PLA. Also, the oxygen permeability of PSH 6 was 37% lower than that of the neat PLA.

Section: Resultsmentioning

confidence: 99%

The effect of organo‐modified silicate nanolayers on the oxygen and water vapor barrier properties of poly(lactic acid)

Shabanian

2018

J Chinese Chemical Soc

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“…Also, for further comparison studies in the resulted nanocomposites properties, PAMPS‐co‐PAA modified Mg‐Al LDH (ALDH) was used as another organo modified LDH for preparation of nanocomposites. ALDH was prepared according to previous work . So, the amounts of ALDH were 2 and 5 mass% in the PAI/ALDH nanocomposites (PAIAN 2 and PAIAN 5).…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, the diacid 3 content grafted on the surface of LDH nanoparticles in DLDH and ALDH were obtained almost 15.1% and 16.07%, respectively (Figure ). For further study and comparison, the TGA thermogram of ALDH is also shown in Figure . As shown in Figure , the thermal stability of ALDH was lower than the DLDH, which it can be related to the aliphatic structure in the organic modifier of ALDH.…”

Section: Characterization Of the Pai/ldh Nanocompositesmentioning

confidence: 99%

“…These better thermal properties can be due to the better dispersion of ALDH in the PAI matrix compared to DLDH. With comparison of XRD results of DLDH and ALDH, it can be concluded that the PAMPS‐co‐PAA as water soluble polymer modifier has better penetrated into the interlayers of LDH. This more d‐value in ALDH, compared to DLDH, may have been caused a uniform dispersion of LDH sheets in the PAI matrix and consequently led to the higher thermal stability.…”

Section: Characterization Of the Pai/ldh Nanocompositesmentioning

confidence: 99%

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Influence of imide functionalized organo‐modified Mg‐Al layered double hydroxide on the thermal and mechanical properties of new aliphatic‐aromatic poly (amide‐imide)

Shafiei-Navid

Shabanian

2018

Applied Organom Chemis

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A new dicarboxylic acid modified Mg‐Al LDH (DLDH) containing imide groups was prepared and its effects on the thermal and mechanical properties of the new synthesized aliphatic‐aromatic poly (amide‐imide) (PAI) were investigated via preparation of PAI/nanocomposite films by solution casting method. The results of X‐ray diffraction (XRD), field emission‐scanning electron microscopy (FE‐SEM) and transmission electron microscopy (TEM) showed a uniform dispersion for LDH layers into the PAI matrix. For comparison, the effects of polyacrylic acid‐co‐poly‐2‐acrylamido‐ 2‐methylpropanesulfonic acid (PAMPS‐co‐PAA) modified Mg‐Al LDH (ALDH) on the PAI properties were also studied. The thermogravimetric analysis (TGA) results exhibited that the temperature at 5 mass% loss (T5) increased from 277 °C to 310 °C for nanocomposite containing 2 mass% of DLDH, while T5 for nanocomposite containing 2 mass% of ALDH increased to 320 °C, along with the more enhancement of char residue compared to the neat PAI. According to the tensile test results, with 5 mass% DLDH loading in the PAI matrix, the tensile strength increased from 51.6 to 70.8 MPa along with an increase in Young's modulus. Also the Young's modulus of PAI nanocomposite containing 5 mass% ALDH reduced from 1.95 to 0.81 GPa.

“…The improvement of the thermal and flame retardancy behaviors along with mechanical properties of polymers such as PLA can be achieved by addition of flame retardant additives along with nanoparticles and organo‐modified nanoparticles . The thermal and fire resistance of polymers have been improved by the addition of an organic additive.…”

Section: Introductionmentioning

confidence: 99%

Design and preparation of poly(lactic acid) hydroxyapatite nanocomposites reinforced with phosphorus‐based organic additive: Thermal, combustion, and mechanical properties studies

Polymers for Advanced Techs

Shafiei-Navid

2019

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A new phosphorus-based organic additive (PDA) was designed and successfully synthesized using a three-component reaction for improvement of the thermal and combustion resistance of polylactic acid (PLA). For compensate for mechanical properties of PLA, hydroxyapatite nanoparticles was modified via in situ surface modification with PDA and was used for preparation of PLA nanocomposites. The structure and morphology as well as thermal, combustion, and mechanical properties of the all PLA systems were investigated. The X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) results indicated that the presence of PDA as surface modifier has been necessary for a desirable dispersion of hydroxyapatite (HA) nanoparticles in the PLA matrix. The thermal, combustion, and mechanical properties of the PLA system films were investigated using thermogravimetric analysis (TGA), microscale combustion calorimeter (MCC), and tensile test, respectively. The initial decomposition temperature and char residue of PLA containing 6 mass% of PDA along with 2 mass% HA nanoparticles were increased 20°C and 12% respectively, compared with that of the neat PLA. The peak of heat release rate was decreased from 566 W/g for the neat PLA to 412 W/g for PLA containing 2 mass% of PDA along with 6 mass% HA nanoparticles. By incorporation of only 2 mass% HA nanoparticles and 6 mass% of PDA, the tensile strength was obtained 51 MPa higher than that of the neat PLA.