Physico-mechanical, thermal and morphological behaviour of polyurethane/poly(methyl methacrylate) semi-interpenetrating polymer networks

Kumar, Harinandan; Kumar, Ashwani; Siddaramaiah,

doi:10.1016/j.polymdegradstab.2005.07.003

Cited by 38 publications

(26 citation statements)

References 32 publications

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“…This can be attributed to the synergistic effect of MMT and matrix present in the composite. The higher the values of oxidation index (OI), the higher will be the thermal stability (33,34). From the table it was observed that the oxidation index values increases with an increase in MMT content and it lies in the 0.014-0.35 range.…”

Section: Resultsmentioning

confidence: 99%

Thermal Degradation Kinetics of Polyurethane/Organically Modified Montmorillonite Clay Nanocomposites by TGA

Pashaei

Siddaramaiah²,

Syed

2010

Journal of Macromolecular Science, Part A

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Polyurethane (PU) has been prepared by using polyether polyol (jagropol oil) and 1,6-hexamethylene diisocyanate (HMDI) as a cross-linker. The organically modified montmorillonite clay (MMT) is well-dispersed into urethane matrix by an in situ polymerization method. A series of PU/MMT nanocomposites have been prepared by incorporating varying amounts of nanoclay viz., 1, 3, 5 and 6 wt %. Thermogravimetric analysis (TGA) of the PU/MMT nanocomposites has been performed in order to establish the thermal stability and their mode of thermal degradation. The TGA thermograms exhibited the fact that nanocomposites have a higher decomposition temperature in comparison with the pristine PU. It was found that the thermal degradation of all PU nanocomposites takes place in three steps. All the nanocomposites were stable up to 205 • C. Degradation kinetic parameters of the composites have been calculated for each step of the thermal degradation processes using three mathematical models namely, Horowitz-Metzger, Coats-Redfern and Broido's methods.

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Section: Resultsmentioning

confidence: 99%

Thermal Degradation Kinetics of Polyurethane/Organically Modified Montmorillonite Clay Nanocomposites by TGA

Pashaei

Siddaramaiah²,

Syed

2010

Journal of Macromolecular Science, Part A

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“…La velocidad de prueba fue 2.5 cm/min a una temperatura (19 ± 2) °C, según la norma ASTM D638. Las dimensiones de la muestra fueron láminas de (40 × 6 × 3) mm 3 . Para cada muestra de tres a cinco replicas fueron evaluadas en las mismas condiciones.…”

Section: Caracterización De Los Sinsunclassified

“…Dentro de estos aceites, especial interés ha recibido el de ricino ya que se caracteriza por ser uno de los pocos aceites vegetales cuya composición se reduce casi a la de un solo componente: el 90% corresponde al triglicérido del ácido ricinoléico [1,2] . Kumar et al estudiaron ampliamente la síntesis y caracterización de redes interpenetradas de polimetilmetacrilato (PMMA) y poliuretano obtenido a partir del aceite de ricino, sin ser sometido a modificaciones en su estructura [3] .…”

Section: Introductionunclassified

[No Title Available]

et al. 2011

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Resumen: El aceite de ricino se modificó por transesterificación con pentaeritritol. Paralelamente, se utilizó la reacción de glucosilación con glicerol para dividir el almidón en unidades monosacáridos. El glucósido obtenido reaccionó por transesterificación con el aceite modificado por transesterificación con pentaeritritol. Se determinó el índice de hidroxilo de los poliol-glucósidos en función del contenido de pentaeritritol y almidón utilizados en la síntesis. Se sintetizaron redes interpenetradas de polímero de manera simultánea (SINs) con diferentes relaciones en peso poliuretano/PMMA de 100/0, 90/10, 80/20, 70/30, 60/40 y 50/50. Para la síntesis de la red de poliuretano (PU) se utilizaron los poliol-glucósidos y diisocianato de isoforona (IPDI) o con una relación NCO/OH = 1 y para la síntesis de la red de polimetilmetacrilato (PMMA) se utilizó peróxido de benzoílo como agente iniciador y dimetacrilato de etilenglicol como agente entrecruzante. Los SINs se caracterizaron por sus propiedades fisicomecánicas como resistencia al ataque químico, dureza, resistencia a la tensión y elongación de ruptura. La estabilidad térmica de los SINs se determinó usando análisis termogravimétrico (TGA). La morfología de superficie se determinó usando microscopia electrónica de barrido (SEM) y mostró una morfología de dos fases para todos los SINs. Palabras-clave: Aceite de ricino, almidón, glucosilación, redes interpenetradas de polímero, polimetilmetacrilato (PMMA). Physico-mechanical, Thermal and Morphological Behaviour of Simultaneous Interpenetrating Polymer Networks Based on Polyurethane from Modified Castor Oiland Starch/Poly(Methyl Methacrylate)Abstract: Castor oil was modified by transesterification with pentaerithritol. In a parallel step, starch was divided into monosaccharide units by glycosylation in order to obtain products with high hydroxyl content. The values of hydroxyl index were measured according to the content of pentaerithritol and starch used in the synthesis. Novel simultaneous interpenetrating polymer networks (SINs) of polyurethane (PU) and poly(methyl methacrylate) (PMMA) in different weight ratios of 100/0, 90/10, 80/20, 70/30, 60/40 and 50/50 were prepared based on polyol-glucosides. The polyurethane network was created by reacting the poliol-glucosides with isophorone diisocyanate maintaining a molar ratio NCO/OH = 1. The PMMA network was synthesized using benzoyl peroxide as initiator and ethylene glycol dimethacrylate as the crosslinker. The SINs were characterized in their mechanical properties, such as Shore A hardness, tensile strength and elongation at break. Thermal stability of SINs was measured using thermogravimetric analysis (TGA). Surface morphology measured using scanning electron microscope (SEM) showed two-phase morphology for all the SINs. SINs based on polyurethane from castor oil modified and poly(methyl methacrylate) show limited compatibility at low concentrations of PMMA, but are totally incompatible at higher concentrations of PMMA.

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“…In order to prevent catastrophic failures of polymeric components, it is essential to understand the environmental effect on polymers. 17 In biomedical applications, environmental stability tends to be particularly important in three areas: processing, sterilisation, and long term implantation. Degradation during process is primarily chemical and thermal in nature; sterilisation effects can be thermal, radiative, or hydrolytic.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and <I>In-Vitro</I> Analysis of Degradative Resistance of a Novel Bioactive Composite

Khan¹,

Aziz²,

Paul³

et al. 2008

j bionanosci

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The biostability of the polymer is one of the critical parameter to use them for biomaterial application. Polyurethane being one of the most compliant polymer but there are concerns regarding its resistance to degradation, particularly from hydrolysis and oxidation. The aim of this study is to synthesise a novel bioactive composite by creating a covalent linkage between polyurethane and nano-apatites and to analyse the in-vitro hydrolytic degradation of a series of newly synthesised polyurethane (PU) and polyurethane/nano-hydroxyapatite (PU/n-HA) composites. Nanoapatite powder was produced through sol-gel technique. A novel polyurethane composite material was prepared by chemically bonding the n-HA to the diisocyanate component in the polyurethane backbone by utilising solvent polymerisation. The concentration of nano-apatite was 5, 10, 15 and 20% wt/wt in polyurethane. Hydrolytic degradation of the PU and PU/n-HA composites were carried out both in deionised water and in phosphate buffer solution (PBS) having (pH 7.4) at 37 C for a predetermined time interval of 90 days. The PU and PU/n-HA composites were physically and chemically characterised by using contact angle measurement, weight loss, Fourier Transform Infrared spectroscopy couples with Photoacoustic Sampling Cell (FTIR-PAS), Raman Spectroscopy, X-ray Diffraction (XRD) and Scanning electron microscopy (SEM). These characterisations showed that with the addition of n-HA the composite exhibits hydrophobic behaviour and degradation rate reduces due to covalent linkage between n-HA and PU. Hence it has been concluded that the degradation rate of the newly developed PU/n-HA composites can be controlled, which helps in tailor making the biomaterial for specific applications.

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Physico-mechanical, thermal and morphological behaviour of polyurethane/poly(methyl methacrylate) semi-interpenetrating polymer networks

Cited by 38 publications

References 32 publications

Thermal Degradation Kinetics of Polyurethane/Organically Modified Montmorillonite Clay Nanocomposites by TGA

Thermal Degradation Kinetics of Polyurethane/Organically Modified Montmorillonite Clay Nanocomposites by TGA

[No Title Available]

Synthesis and <I>In-Vitro</I> Analysis of Degradative Resistance of a Novel Bioactive Composite

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