GENERALITE

sur

LES POLYMERES

 

 

I] Introduction.                                                                                               p1

 

                        1) Historique.                                                                                  p1

 

                        2) Définition et exemples de polymères.                                            p1

 

                                   a) Définition du polymère.                                                                          p1

 

                                   b) Exemple de polymères usuels.                                                               p2

 

                        3) Différents types de polymères.                                                      p3

 

                                   a) Les homopolymères.                                                                               p4

 

                                   b) Les copolymères.                                                                                    p4

 

 

II] Caractérisation d’un polymère & diagramme masse-température. p5

 

                        1) Comment définir la masse d’un polymère ?                                 p5

 

                        2) Structure du polymère : plusieurs niveaux de polymères.              p7

 

                                   a) Structure primaire.                                                                                  p7

 

                                   b) Structure secondaire.                                                                              p8

 

                                   c) Structure tertiaire.                                                                                   p9

 

                        3) Analyses thermiques.                                                                   p9

 

                        4) Diagrammes Masse - Température.                                             p10

 

                        5) Diagrammes Contraintes / Déformations.                                    p11

 


 

 

 

POLYMERISATION

par ETAPES

POLYCONDENSATION

 

 

I] Introduction générale à la polymérisation par étapes.                         p13

 

                        1) Généralités.                                                                                 p13

 

            2) Différents types de polymérisations par étapes et taux de conversion.     p14

 

                        3) Comparaison entre différents types de polymérisations.                p14

 

 

II] Cinétique générale des réactions de polymérisation par étapes.       p16

 

                        1) Equation de Carothers.                                                               p16

 

                        2) Cinétique d’une polycondensation diacide - dialcool.                            p17

 

                                   a) Polycondensation auto - catalysée.                                             p17

 

                                   b) Polycondensation avec catalyse.                                                            p19

 

 

III] Contrôle des masses molaires.                                                               p20

 

                        1) Distribution des masses molaires.                                                p20

 

                        2) Contrôle des masses.                                                                   p21

 

 

IV] Branchements / Réticulation.                                                                         p23

 

 

V] Applications.                                                                                                       p24

 

                        1) Les polyamides aliphatiques.                                                       p24

 

                        2) Les polyesters.                                                                             p25


 

                        3) Les polyuréthanes.                                                                      p25

 

                        3) Les résines.                                                                                 p26

 

                                   a) Les résines phénoliques.                                                          p26

 

                                   b) Les polymères époxy.                                                             p27


 

 

 

POLYMERISATION

en CHAINE

 

 

I] Caractéristiques générales des polymérisations en chaîne.                 p28

 

                        1) Généralités.                                                                                 p28

 

                        2) Différence entre polycondensation et polymérisation en chaîne.   p29

 

                        3) Nature des centres actifs.                                                             p30

 

 

II] Polymérisation radicalaire.                                                                     p31

 

                        1) Formation du centre actif.                                                           p31

 

                                   a) Amorceur thermique.                                                              p31

 

                                   b) Amorceur redox.                                                                    p32

 

                                   c) Amorceurs de type radiations ionisantes.                                              p32

 

                                   d) Conditions d’utilisation de l’amorceur.                                        p33

 

                        2) Cinétique d’une polymérisation radicalaire.                                p33

 

                                   a) Amorçage.                                                                            p33

 

                                   b) Propagation.                                                                                            p34

 

                                   c) Terminaison.                                                                                            p34

                                               La première est une réaction de recombinaison.                           p34

                                               La deuxième est une réaction de dismutation.                              p34

 

                                   d) Longueur de chaîne cinétique.                                                   p35

 

                                   e) Réaction de transfert.                                                                             p35

                                               Les thiols.                                                                        p36

                                               Les constituants du milieu.                                                               p36

 

                                   f) Inhibition.                                                                              p37


                                   g) Effet Tromsdorff.                                                                   p38

 

                                   h) Durée de vie moyenne.                                                            p39

 

                        3) Thermodynamique.                                                                     p39

 

                        4) Exemples de polymères « radicalaires »industriels.                      p40

 

                                   a) Le polyéthylène (PE).                                                                             p40

 

                                   b) Le polystyrène (PS).                                                               p41

 

 

III] Polymérisations ioniques.                                                                       p42

 

                        1) Généralités.                                                                                 p42

 

                        2) La polymérisation anionique.                                                      p43

 

                                   a) Monomères utilisés.                                                               p43

 

                                   b) Les amorceurs.                                                                      p43

 

                                   c) Etude cinétique.                                                                                       p44

                                               L’amorçage :                                                                   p44

                                               La propagation :                                                                               p44

 

                                   d) Application : laboratoires et industrie.                                        p46

 

                                                Particularité de la masse :                                                                p46

                                               Conception d’architecture particulière :                                          p47

                                               Contrôle des extrémités de chaîne :                                                  p47

                                               Rôle d’amorceur :                                                                             p48

 

                        3) La polymérisation cationique.                                                     p48

 

                                   a) Amorçage.                                                                                               p48

                                               Acide de Brönsted :                                                                           p48

                                               Acide de Lewis :                                                                                p48

                                               Sels de cations stables :                                                                     p49

 

                                   b) Propagation.                                                                          p50

 

                                   c) Terminaison.                                                                         p51

 

                                   d) Polymérisation vivante.                                                           p51

 

                                   e) Réaction de transfert à l’amorceur.                                            p52