Properties of linear elastomeric polyurethanes

Cooper, Stuart L.; Tobolsky, A. V.

doi:10.1002/app.1966.070101204

Cited by 535 publications

(242 citation statements)

References 17 publications

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“…O segundo bloco, chamado de segmento rígido, é formado pela reação de um diisocianato com um diol de baixa massa molar, chamado de extensor de cadeia. O segmento rígido se comporta como uma reticulação dispersa na fase flexível e pode ser fundido sem degradação das ligações uretânicas, permitindo o seu processamento como termoplástico [2][3]. Devido às diferentes combinações dos segmentos rígidos e flexíveis podem-se formular materiais com diferentes propriedades, desde macios e flexíveis até duros com alto módulo de elasticidade [4,5].…”

Section: Introductionunclassified

Mechanical and Thermal Properties and Morphology of Thermoplastic Polyurethane (TPU)/Clay Composites

et al. 2015

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ResumoNeste trabalho, compósitos de elastômero termoplástico de poliuretano (TPU) foram preparados com diferentes teores de argila (1, 3 e 10% m/m). A argila Cloisite  30B (C30B) foi incorporada na matriz de TPU via processamento por fusão em uma extrusora de dupla rosca. O método de síntese do TPU foi a polimerização em duas etapas do poliol poliéster e do di-isocianato de 4,4' difenil metano com butano-1,4-diol como extensor de cadeia. A dispersão da argila e seu efeito sobre as propriedades mecânicas e térmicas dos compósitos foram investigadas. A caracterização dos compósitos de TPU com argila foi realizada por meio das análises de microscopia eletrônica de varredura, microanálise de energia dispersiva e difração de raios X. As propriedades mecânicas foram avaliadas através da resistência à tração. O TPU com 3% m/m de argila apresentou os melhores resultados com aumento nos valores de tensão e alongamento na ruptura (28% e 35%, respectivamente), quando comparado ao TPU puro (amostra sem argila). As análises de calorimetria diferencial de varredura e termogravimetria, para os compósitos, indicaram que a argila não afetou significativamente as temperaturas de transição vítrea, de fusão e de degradação da matriz polimérica, mas restringe o movimento molecular. Palavras-chavePoliuretano, Argila, Compósitos, Morfologia, Propriedades Mecânicas, Propriedades Térmicas Mechanical and Thermal Properties and Morphology of Thermoplastic Polyurethane (TPU)/Clay CompositesAbstract In this study, thermoplastic polyurethane (TPU) composites were prepared with different nanoclay contents (1, 3 and 10 wt%). The nanoclay Cloisite  30B (C30B) was dispersed in the TPU matrix by melt processing using a twin-screw extruder. The synthesis method of TPU involved the two-step bulk polymerization of polyesterpolyol and 4,4' diphenylmethanediisocyanate with butane-1,4-diol as the chain extender. The dispersion of the nanoclay particles and its effect on the mechanical and thermal properties of the composites was investigated. The characterization of TPU/nanoclay composites was carried out by means of scanning electron microscopy, energy dispersion microanalysis and X ray diffraction. The mechanical characterization was performed through determination of the tensile strength. The TPU 3 wt% composite showed the best improvement with increases in stress and tensile at break (28% and 35%, respectively), compared to the neat TPU (sample without nanoclay). The differential scanning calorimetry and thermogravimetry analyses for composites indicated that the nanoclay did not affect significantly the glass transition, melt, and degradation temperatures of the polymeric matrix, but reduces the molecular mobility.

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Section: Introductionunclassified

Mechanical and Thermal Properties and Morphology of Thermoplastic Polyurethane (TPU)/Clay Composites

et al. 2015

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“…The hard segment (HS) contains urethane linkages generated by the reaction of diisocyanate and shortchain diols and influences the mechanical properties, such as the elasticity, hardness, and tearing strength. The in-favorable thermodynamic immiscibility between HS and SS caused due to the formation of hydrogen bonds in HS drives the system to form a microphase-separated structure at room temperature [1]. TPUs are widely used for different purposes, such as automobile parts, building materials, sports goods, and medical equipments [2].…”

Section: Introductionmentioning

confidence: 99%

Effects of glycerol monosterate on TPUs crystallization and its foaming behavior

Hossieny¹,

Nofar²,

Shaayegan³

et al. 2014

AIP Conference Proceedings

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“…The termination is supposed to occur with the same frequency by combination and disproportionation and the dependence relatively to the nature of the radicals involved is expressed in Table 12. System II is obtained from System I by replacing r 1 ¼ 0.24 for r 1 ¼ 10 4 and, Table 11 Set of chemical reactions considered in a non-linear radical copolymerization including branching by transfer to polymer and propagation on terminal double bonds (continued from …”

Section: Kinetic Parameters and Operation Conditionsmentioning

confidence: 99%

“…A particular chemical system of this kind with industrial importance occurs when a diisocyanate reacts with a short diol (hard diol) and a long diol (soft diol). The sequence length distributions of hard and soft segments are long known to determine the microphase separation of segmented polyurethanes [4]. Solutions for the sequence length distributions in batch reactors of the linear polycondensation of three monomers have also long been available from probabilistic approach [5e7], Monte Carlo simulation [8e12] and kinetic modeling [14,15].…”

Section: Introductionmentioning

confidence: 99%

A general kinetic method to predict sequence length distributions for non-linear irreversible multicomponent polymerizations

Dias

Costa

2006

Polymer

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A method to predict the sequence length distribution (SLD) for homogeneous non-linear irreversible multicomponent polymerizations is described. With more than two monomers, it also predicts chain length distributions of the sub-domains containing a prescribed sub-set of the repeating units, but in all possible orderings. Its goal is the analysis of polymerization systems involving complex kinetic schemes in an automated way. The radical terpolymerization of two vinyl monomers with a divinyl monomer and a radical copolymerization including branching by transfer to polymer and by propagation on terminal double bonds are considered as case studies showing the interest of our approach. Finally, the concept of gelation of sequences is presented and discussed in comparison with the related and better known gelation of the population of polymer molecules.

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Properties of linear elastomeric polyurethanes

Cited by 535 publications

References 17 publications

Mechanical and Thermal Properties and Morphology of Thermoplastic Polyurethane (TPU)/Clay Composites

Mechanical and Thermal Properties and Morphology of Thermoplastic Polyurethane (TPU)/Clay Composites

Effects of glycerol monosterate on TPUs crystallization and its foaming behavior

A general kinetic method to predict sequence length distributions for non-linear irreversible multicomponent polymerizations

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