Kinetics of castor oil based polyol–toluene diisocyanate reactions

Ajithkumar, S.; Kansara, Sujata; Patel, Niraj H.

doi:10.1016/s0014-3057(97)00270-x

Cited by 54 publications

(34 citation statements)

References 14 publications

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“…Traditionally, the kinetics of polyurethane formation was extensively monitored by two direct methods that measure the concentration of reactant or reaction products: standard dibutylamine back titration and FTIR spectroscopy [14][15][16]. Back-titration is a well-known method for conventionally titrating for free isocyanate content; however, it is both time and chemical consuming.…”

Section: Polymerization Kineticsmentioning

confidence: 99%

Development of bio-based thermoplastic polyurethanes formulations using corn-derived chain extender for reactive rotational molding

Rashmi¹,

Rusu²,

Prashantha³

et al. 2013

Express Polym. Lett.

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Abstract. Partly bio-based segmented thermoplastic polyurethane (TPU) formulations were developed to fulfill the requirements of the reactive rotational molding process. They were obtained by one-shot bulk polymerization between an aliphatic diisocyanate (1,6-hexamethylene diisocyanate), a polyether polyol as macrodiol (polyethylene glycol) and a biobased corn-derived 1,3-propanediol as chain extender (CE), in presence of a catalyst, at an initial temperature of 45°C. Equivalent TPU formulations with classical petroleum-based 1,3-propanediol were also prepared for a purpose of comparison. TPU with different soft to hard segment (SS/HS) ratios were synthesized by varying the macrodiol and CE concentrations in the formulations. For each formulation, the evolution of the reaction temperature as a function of time was monitored and the kinetics of polymerization was studied by Fourier Transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR). The morphology, thermal properties, solubility in different solvents and tensile properties of the final products were analyzed. All synthesized polyurethanes are 100% linear polymers and the extent of microphase separation, as well as the thermal and mechanical properties highly depends on the HS content, and glass transition temperature and Young modulus can be tuned by adjustment of the SS/HS ratio. All results indicate that petrochemical CE can be replaced by its recently available corn-derived homologue, without sacrificing any use properties of the final polyurethanes.

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Section: Polymerization Kineticsmentioning

confidence: 99%

Development of bio-based thermoplastic polyurethanes formulations using corn-derived chain extender for reactive rotational molding

Rashmi¹,

Rusu²,

Prashantha³

et al. 2013

Express Polym. Lett.

View full text Add to dashboard Cite

show abstract

“…A second-order kinetic is the usual behavior when analyzing the reaction of isocyanate and, in the case of asymmetric diisocyanates reacting without catalyst, two specific velocities have been found. [14] Since the hydroxyl functionality of CO is on average 2.7, the corresponding polyurethanes are mainly thermosets. Several studies have been reported in the literature on the gelation time phenomenon of polyurethanes.…”

Section: Introductionmentioning

confidence: 99%

Polyurethanes Based on Castor Oil: Kinetics, Chemical, Mechanical and Thermal Properties

Hablot

Zheng

Bouquey

et al. 2008

Macro Materials & Eng

198

113

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Polyurethanes based on vegetable oil were synthesized with castor oil and toluene diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate, using dibutyltin dilaurate as a catalyst. The effects of the nature of the diisocyanate on the evolution of the kinetics, as well as the physical and mechanical properties and the thermal stability, of the different synthesized polyurethanes were investigated, and these complement data from the literature on equivalent systems. The polymerization kinetics, degree of swelling and mechanical properties were greatly affected by the diisocyanate nature, whereas the rheological properties and thermal stability were found to be similar for all polyurethanes.magnified image

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“…En el caso donde la concentración de grupos isocianato sea igual a los hidroxilos y/o grupos reactivos, la cinética puede ser de segundo orden [11,12] , además los valores de R 2 para estos sistemas en estudio reafirman esto (Tabla 3). El mecanismo de la catálisis básica de formación de PU's es mostrado en la Figura 2.…”

Section: Resultados Y Análisisunclassified

Síntesis y caracterización de adhesivos reposicionables de poliuretano dispersos en agua, obtenidos a partir de aceite de castor maleinizado

et al. 2010

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Resumen: El presente trabajo se centró en la producción de dispersiones acuosas de poliuretano empleando el método de emulsificación por inversión de fases. Para la síntesis fueron empleados dos polioles: uno comercial tipo poliéster y el otro es aceite de castor maleinizado (MACO); dos diisocianatos, uno aromático Toluen diisocianato (TDI) y otro alifático Hexametilen diisocianato (HDI), siendo poco comunes para esta aplicación. Como emulsificante interno se empleó ácido cítrico el cual es muy económico y de fácil adquisición. Como factores se evaluaron la cantidad de ácido cítrico y la relación molar de grupos isocianato a hidroxilos (NCO/OH), generando un diseño de experimentos factorial 3 2 y minimizando el contenido de sólidos sedimentados. Mediante la metodología de superficie de respuesta, se obtuvo una ecuación polinomial cuadrática por un análisis de regresión múltiple. Los poliuretanos formados fueron evaluados en cuanto a sus propiedades adhesivas y mecánicas (pegajosidad tack, pegajosidad en cinta loop tack, cohesión hold, pelado peel), lo que permitió clasificar el adhesivo como reposicionable, para emplearlo en etiquetas. Palabras-clave: Adhesivos reposicionables, poliuretano, dispersiones, aceite de castor. Synthesis and Characterization of Pressure-Sensitive Adhesives of Waterborne Polyurethane from Maleinizated Castor OilAbstract: This work focused on the production of aqueous dispersions of polyurethane using the emulsification method by phase inversion. For the synthesis two polyols were employed, viz. a commercial polyester and Maleinizated Castor Oil (MACO), with two diisocyanates: one aromatic, toluene diisocyanate (TDI) and another aliphatic, hexamethylene diisocyanate (HDI), which are not common for this application. Citric acid was used as internal emulsifier which is inexpensive and readily available. The parameters were the amount of citric acid and the mole ratio of isocyanate groups to hydroxyl (NCO/OH), generating a 3 2 factorial design, with minimization of the sedimented solids. The surface methodology was used to obtain a quadratic polynomial equation by multiple regression analysis. Polyurethanes synthesized were evaluated for their mechanical and adhesive properties (tack, loop tack, hold, peel). These measurements allowed classifying the polyurethanes synthesized as repositionable adhesives, for use in labels.

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Kinetics of castor oil based polyol–toluene diisocyanate reactions

Cited by 54 publications

References 14 publications

Development of bio-based thermoplastic polyurethanes formulations using corn-derived chain extender for reactive rotational molding

Development of bio-based thermoplastic polyurethanes formulations using corn-derived chain extender for reactive rotational molding

Polyurethanes Based on Castor Oil: Kinetics, Chemical, Mechanical and Thermal Properties

Síntesis y caracterización de adhesivos reposicionables de poliuretano dispersos en agua, obtenidos a partir de aceite de castor maleinizado

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