Biodegradable Polyester / Layered Silicate Nanocomposites

2002 ◽  
Vol 740 ◽  
Author(s):  
Pralay Maiti ◽  
Carl A. Batt ◽  
Emmanuel P. Giannelis
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Layered Silicate ◽  
Layered Silicates ◽  
Melt Extrusion ◽  
Biodegradable Polyester ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Silicate Nanocomposites ◽  
Organically Modified

ABSTRACTNanocomposites of α-hydroxy polyester, polylactide (PLA) and β-hydroxy polyester, polyhydroxybutyrate (PHB) with layered silicates have been successfully prepared by melt extrusion of PLA and PHB with organically modified montmorillonite (MMT) and fluoromica. The mechanical properties of the nanocomposites are improved compared to the neat polymers. Storage modulus increase up to 40% compared with the pure polymers by adding only 2–3 wt% nanoclay. Biodegradation can be controlled by the choice of the nanoclay used.

Nanocomposites Based on Montmorillonite/Acrylic Copolymer for Aqueous Coating of Soft Surfaces

2009 ◽  
Vol 151 ◽  
pp. 129-134 ◽  
Author(s):  
Onur Yılmaz ◽  
Aurica P. Chiriac ◽  
Catalina Natalia Cheaburu ◽  
Loredana E. Nita ◽  
Gürbüz Gülümser ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Layered Silicate ◽  
Acrylic Copolymer ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Film Forming ◽  
Organically Modified ◽  
Polymerization Method ◽  
Structural Characterizations

Nanocomposites based on layered silicate organically modified montmorillonite (Cloisite 20A) and acrylic comonomers (butyl acrylate and methyl methacrylate) were prepared by simple “in situ” batch emulsion polymerization method. The particle size and zeta potential of the emulsions were analyzed. The structural characterizations of the nanocomposites were performed by FTIR, thermal behaviors of the films were investigated by DSC, mechanical properties of the films were tested by DMA and intercalation success was viewed by XRD. The mechanical properties of the nanocomposites were improved significantly especially at the temperatures above Tg. The ultrasonication process was found to be useful for increasing the homogeneity of the emulsions and intercalation success. The obtained nanocomposite emulsions were applied on garment leathers in a finishing formulation as aqueous binders sharing good film forming ability and elasticity.

Biodegradable Nanocomposites of Poly(hydroxybutyrate-co-hydroxyvalerate): The Effect of Nanoparticles

2008 ◽  
Vol 8 (4) ◽  
pp. 1858-1866 ◽  
Author(s):  
Pralay Maiti ◽  
Jaya P. Prakash Yadav
Keyword(s):  
Mechanical Properties ◽  
Layered Silicate ◽  
Layered Silicates ◽  
Thermal And Mechanical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silicate Nanocomposites ◽  
Transmission Electron ◽  
Superior Mechanical Properties ◽  
Biodegradable Nanocomposites

Copolymer of hydroxybutyrate and hydroxyvalerate, P(HB-HV)/layered silicate or hydroxyapatite nanocomposites were prepared via melt extrusion. The nanostructure, as observed from wide-angle X-ray diffraction and transmission electron microscopy, indicate intercalated hybrids for layered silicates. Hydroxyapatite of nanometer dimension is uniformly distributed in matrix copolymer. The nanohybrids show significant improvement in thermal and mechanical properties of the copolymer as compared to the neat copolymer. The layered silicate nanocomposites exhibit superior mechanical properties as compared to hydroxyapatite nanohybrid. The thermal expansion coefficient is significantly reduced in nanohybrids. The biodegradability of pure copolymer and its nanocomposites were studied at room temperatures under controlled conditions in compost media. The rate of biodegradation of copolymer is enhanced dramatically in the nanohybrids. Hydroxyapatite hybrid shows highest rate of biodegradation. The change in biodegradation is streamlined in terms of nature of nanoparticles used to prepare hybrids.

Preparation, Physical and Mechanical Characterization of Montmorillonite/Polyethylene Nanocomposites

2006 ◽  
Vol 312 ◽  
pp. 205-210 ◽  
Author(s):  
V. Pettarin ◽  
Victor Jayme Roget Rodriguez Pita ◽  
Francisco Rolando Valenzuela-Díaz ◽  
S. Moschiar ◽  
L. Fasce ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Clay Platelet ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

In this paper, we report the preparation of polyethylene composites with organically modified montmorillonite. Three different Na+-montmorillonites were modified in order to obtain organoclays and two grades of high-density polyethylene were used as composite matrices. All composites were prepared by melt blending, and their physical and mechanical properties were thoroughly characterized. The extent of clay platelet exfoliation in the composites was confirmed by X-ray diffraction (XRD). Mechanical properties under static and impact conditions were evaluated to assess the influence of the reinforcement on the properties of polyethylene.

The Mechanical and Thermal Properties of Polyoxymethylene (POM)/Organically Modified Montmorillonite (OMMT) Engineering Nanocomposites Modified with Thermoplastic Polyurethane (TPU) Compatibilizer

2012 ◽  
Vol 714 ◽  
pp. 201-209 ◽  
Author(s):  
Agnieszka Leszczyńska ◽  
Krzysztof Pielichowski
Keyword(s):  
Thermal Properties ◽  
Formic Acid ◽  
Mass Loss ◽  
Thermoplastic Polyurethane ◽  
Layered Silicate ◽  
Thermal Stabilization ◽  
Mechanical And Thermal Properties ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

In this work the effect of macromolecular polyurethane compatibilizer on the structure, mechanical and thermal properties of polyoxymethylene/organically modified montmorillonite (POM/OMMT) nanocomposites was investigated. The thermal stability of obtained systems was significantly enhanced by compatibilizer both in oxidative and inert atmosphere. The thermoanalytical methods (TG-FTIR and TG-MS) were used for identification of gaseous products of degradation. The results showed less intensive evolution of formaldehyde and formic acid during the thermal degradation of POM/TPU/OMMT nanocomposites. Both formaldehyde and formic acid had an autocatalytic effect on degradation of neat POM and POM/MMT nanocomposites, especially in the initial stage of the process. However, in the presence of TPU the monomer formed in depolymerization reaction was captured most probably by urethane linkage in a formylation process. The decreased concentration of catalytic agent is considered as a cause of the reduced rate of mass loss of POM/TPU/OMMT nanocomposites. Interestingly, during thermooxidative degradation the temperature of maximum rate of mass loss was shifted towards higher temperature more than it could be anticipated from the TGA results obtained for neat POM, POM/TPU blend and POM/OMMT nanocomposite material with corresponding contents of nanofiller and compatibilizer. It is likely that the mechanism of thermal stabilization may be also related to the physical barrier effect of layered silicate towards oxygen diffusion. Both chemical and physical mechanisms of stabilization are referred to the structure and interfacial area developed in nanocomposite materials and thus can be influenced by addition of a compatibilizer. The obtained POM/TPU/OMMT nanocomposites revealed higher impact strength as compared to POM/OMMT materials due to the presence of elastomeric domains facilitating the dissipation of impact energy.

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