Jean‐Pierre Pascault

Institut National des Sciences Appliquées de Lyon

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Jean‐François Gérard

Ingenierie des Materiaux polymeres

Françoise Méchin

Ingenierie des Materiaux polymeres

Roberto J. J. Williams

National University of Mar del Plata

J. Galy

Ingenierie des Materiaux polymeres

H. Sautereau

Institut National des Sciences Appliquées de Lyon

Benoît Magny

Arkema (France)

Ludovic Valette

Alstom (France)

Frédéric Lortie

Université Claude Bernard Lyon 1

ÉD

Éric Drockenmuller

Université Claude Bernard Lyon 1

ÉE

Éliane Espuche

Ingenierie des Materiaux polymeres

Cooperative Institutions

Centre National de la Recherche Scientifique

149

Institut National des Sciences Appliquées de Lyon

123

Université Claude Bernard Lyon 1

Ingenierie des Materiaux polymeres

Université Jean Monnet

Instituto de Investigaciones en Ciencia y Tecnología de Materiales

Arkema (France)

Laboratoire de Chimie

École d'Ingénieurs en Chimie et Sciences du Numérique

National University of Mar del Plata

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General Concepts about Epoxy Polymers

Jean‐Pierre Pascault Roberto J. J. Williams

This chapter contains sections titled: Polymerization Chemistry of Epoxy Monomers Transformations During the Formation of an Epoxy Network General Properties of Epoxy Networks References

10.1002/9783527628704.ch1

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Citations (61)

Organic and Organic-Inorganic Block Copolymers for Nanostructuration of Polymer Networks

HAL (Le Centre pour la Communication Scientifique Directe) (2011)

Jean‐François Gérard Julien Bernard Li-Xin Dai J. Galy Frédéric Lortie

Organic component

Source

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Bio-based Unsaturated Polyester Resins

HAL (Le Centre pour la Communication Scientifique Directe) (2013)

Jean‐Pierre Pascault

Unsaturated polyester

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New polyurethane and polyurethane-acrylate materials prepared from aqueous dispersions

HAL (Le Centre pour la Communication Scientifique Directe) (2004)

M. Pineda-Herrera Françoise Méchin Jean‐Pierre Pascault

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Structured Thermoplastic/Thermoset Blends Using Block Copolymers

Macromolecular Symposia (2006)

Thomas Fine Jean‐Pierre Pascault

Abstract Thermoplastic/thermoset blends have been compatibilized by block copolymers. The thermoplastic is poly(phenylene ether) and the thermoset precursors are a liquid epoxy, diglycidyl ether of bisphenol A (DGEBA) and an aromatic diamine (4,4′ methylene bis [3 chloro 2,6 diethylaniline], MCDEA). The triblock poly(styrene‐ b ‐butadiene‐ b ‐methyl methacrylate), SBM has been chosen because (i) PS blocks interact very favourably with PPE (ii) PMMA blocks remain miscible with the thermoset during the whole curing process, and (iii) PB mid blocks are expected to cover the interface. Morphologies of blends were observed by Transmission Electron Microscopy and phase composition evaluated by Dynamic Mechanical Thermal Analysis. It was observed that the strong repulsion between PPE and PMMA blocks governs the organization of the blend before and during the curing process. During polymerization a purification of the matrix is induced. As expected, a large proportion of block copolymer is at the interface between the matrix and nodules. It was demonstrated that the number of SBM micelles and their degree of dispersion is the main parameter controlling the mechanical properties.

Thermosetting polymer

Diglycidyl ether

Thermoplastic elastomer

10.1002/masy.200651352

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Citations (13)

Rheological Properties of (Meth)acrylic Cross-Linked Polymer Microparticles, 1. Comparison with Linear Polymers in Bulk and in Non-Reactive Solvents

Macromolecular Materials and Engineering (2002)

Ludovic Valette Jean‐Pierre Pascault Benoît Magny

The rheological properties of cross-linked polymer microparticle (CPM) solutions have been studied regarding the influence of the CPM structure. CPM have been synthesized by dispersion polymerization, with the degree of cross-linking varying between 0 and 10% (i.e., with the concentration of diacrylate monomer cross-linking agent ranging from 0 to 10 mol-%). The structure of the CPM has also been changed by using optionally a semi-crystalline stabilizing agent monomer, based on a C18 aliphatic chain. The resulting CPM were either semi-crystalline or totally amorphous with a high Tg. Typical linear acrylic polymers (acrylic LP) have also been synthesized by solution polymerization and compared to the CPM. Dilute solutions in toluene or xylene were used to measure the intrinsic viscosity of polymers with a capillary viscosimeter. More concentrated solutions in the same solvents were used to determine the influence of the shear rate and of the CPM structure and concentration on the solution viscosity with a cone and plate viscosimeter. Because of the intramolecular cross-links, weak interactions took place in dilute solutions between the CPM, resulting in very low viscosity and low dependence on the molar mass, with respect to the acrylic LP. A low molar mass dependence was also found for CPM in bulk, without critical molar mass due to chain entanglement. Concentrated CPM solutions led to shear thinning behavior. It greatly depended on the microparticle structure, especially on the presence of the C18 aliphatic chains. Solutions of cross-linked polymer microparticles without these aliphatic chains can decrease the viscosity by 500 times between low and high shear rates. Thixotropy was observed for CPM solutions with concentrations higher than 20 wt.-%. The recovery time was highly influenced by the CPM concentration, ranging from a few tens of seconds to about two minutes.

Molar mass

Emulsion polymerization

Shear thinning

10.1002/1439-2054(20020101)287:1<41::aid-mame41>3.3.co;2-o

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Gas permeability of model polyurethane networks and hybrid organic-inorganic materials: Relations with morphology

Journal of Applied Polymer Science (1997)

Celina Maria Damian Éliane Espuche M. Escoubes S. Cuney Jean‐Pierre Pascault

Various polyurethane (PU) and hybrid organic-inorganic networks based on isocyanate chemistry were synthesized using a two-stage method. All the networks were amorphous. For PU membranes the morphology and the permeability coefficients of different gases (H2, N2, O2) were a function of the polarity and the chain length of the soft segment and a function of the composition of the networks. The membranes based on the same soft segment chain length and on the same molar composition were structurally nanoheterogeneous systems for the less polar soft segments (α, ω-hydroxy-terminated hydrogenated polybutadiene and a fatty acid oligoester). They were homogeneous for a polycaprolactone type soft segment. The gas diffusion was appreciably hindered in the case of better miscibility between the soft chains and the hard crosslinks. Decreasing the soft segment length decreased the gas permeability coefficient of the network. As the chemical compositions were changed by increasing the soft segment content, an increase in permeability coefficients was observed. The morphology and transport properties of PU networks and hybrid organic-inorganic networks with low inorganic content were compared for the same soft segment content. The similarities observed between the two types of networks led us to conclude that the organic or inorganic nature of the crosslinking agent has no influence on the gas transport properties of these networks. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2579–2587, 1997

Miscibility

Barrer

Morphology

10.1002/(sici)1097-4628(19970919)65:12<2579::aid-app27>3.0.co;2-u

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Citations (13)

Reactions in aminosilane‐epoxy prepolymer systems. II. Reactions of alkoxysilane groups with or without the presence of water

Journal of Polymer Science Part A Polymer Chemistry (1991)

Aîcha Sérier Jean‐Pierre Pascault T. M. Lam

Abstract The hydrolysis and reactions of alkoxy silane groups have been studied on a model compound (TA) prepared from 2 mol of phenyl glycidyl ether and 1 mol of aminopropyl triethoxy silane. At low (40°C) and high (140°C) temperatures, the monomer conversion and the evolution of the molecular mass are followed by size exclusion chromatography (SEC). During the same reaction time, the evolution of the functional groups, hydroxyl CHOH, ethoxy OC 2 H 5 , and siloxane SiOSi, is observed by FTIR spectroscopy. Without the presence of water, reactions between hydroxyl and ethoxy silane lead to gelation at the end of the reaction. A by‐product, probably a cyclic tetramer is also formed. After the hydrolysis, the reaction of the model compound is quite different. The product of reaction is always soluble, even after a treatment at high temperatures, and the evolution of the molecular mass versus the reaction time seems to correspond to the condensation giving a dead cyclic tetramer. From this study it is evident that the curing cycle has a great influence on the properties of the interface of a composite based on a epoxy matrix.

Siloxane

Prepolymer

Condensation reaction

Rearrangement reaction

Tetramer

10.1002/pola.1991.080290806

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Citations (28)

Synthesis and properties of self‐crosslinkable thermoplastic polyurethanes

Journal of Applied Polymer Science (2007)

Aude Lapprand Françoise Méchin Jean‐Pierre Pascault

Abstract The chemical modification of a thermoplastic polyurethane (TPU) has been realized by the grafting of polyisocyanates onto urethane groups through allophanate bonds to prepare self‐crosslinkable but still thermoplastic materials. Because of the lateral isocyanate groups, the resulting polymer can be easily crosslinked by the ambient moisture. However, because of the highly viscous character of the TPU even at a high temperature, this chemical reaction must be performed with a twin‐screw extruder above 190°C. The ability of linear, segmented TPUs to undergo physical (micro)structuration that strongly depends on their thermal history has been widely described in the literature, and these transformations usually occur in the same temperature range as that used for performing our chemical reactions. Moreover, the thermally reversible character of urethane and allophanate bonds above ∼ 170°C is also well‐known. Therefore, the precise characterization of the thermomechanical properties of the initial and modified materials is quite delicate because microstructural phenomena and chemical rearrangements can compete and always have to be considered simultaneously. Considering these restrictions, we have nevertheless demonstrated that the structural transformation is faster than crosslinking for a partially crosslinked TPU, but microphase separation is no longer possible for a TPU with a gel fraction higher than 50%. The chemical crosslinks of the modified TPU are reversible, but they still allow an important increase in the thermomechanical properties at a high temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 99–113, 2007

Thermoplastic polyurethane

Isocyanate

10.1002/app.26086

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Citations (23)

Additive Effects on the Toughening of Unsaturated Polyester Resins

Advances in chemistry series (1993)

Laurent Suspène Yeong Show Yang Jean‐Pierre Pascault

An elastomer additive, carboxy-terminated acrylonitrile-butadiene copolymer, was used for toughening in the free radical cross-linking copolymerization of unsaturated polyester (UP) resins. For molded parts, Charpy impact behavior was generally enhanced and the number of catastrophic failures was reduced. The miscibility and interfacial properties of additive and resin blends play important roles in the toughening process. Phase-diagram studies showed that the elastomer additive is immiscible with the UP resin and is phase-separated from the resin matrix during curing. This phase-separation phenomenon is similar to that in the low-profile mechanism of UP resins. Additive-resin system miscibility greatly influences curing morphology. Microvoids occurred in the additive phase of cured resin because of shrinkage stress. The intrinsic inhomogeneity of the polyester network and the existence of microvoids in the final product limit the toughening effect of additives on unsaturated polyester resins.

Unsaturated polyester

Toughening

Miscibility

10.1021/ba-1993-0233.ch007

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Citations (17)