课件11-逐步聚合

OverviewofStep LinearStepCondensation Non-linearStepCondensationABrief

AdditionCondensationRingRadicalRadical

AnionicAnionicBulkBulkABrief (chain

(step ABrief (chainABrief (step。ABriefAABrief 1.StepStep CharacteristicsofStep ClassificationofStep1.Step1.Step 1.StepPolymerization 产 度

1.Step 1.Step 1.Step 等Step +Step EquilibriumofLinearCondensation KineticsofLinearCondensation EffectsonMolecularWeightandDistributionLinearCondensation Non-LinearCondensation CondensationPolymerization 缩聚反应没有特定的反应活性中心，每个单体都可以看缩聚反应无所谓链、链增长和链终止，缩聚反应的 4050C，所以在一般聚合温度下是可逆平衡反应。nHOOC(CH2)4COOH n CO(CH2)4COOCH2CH2OnH+(2n-1)H 平衡缩聚：大多数缩聚反应是可逆平衡反应，即反应进行一段不平衡缩聚：即不可逆缩聚，当单体活性较高时，逆反应速。 nHO O n

(n-1) nHO O n

(n-1) n

n

n

> nH2N R COOH H HN R n

(n- 官能团取代基的电负性：羧酸衍生物的活性取决于酰基取代基的 丙三醇，季戊醇 双酚

异酸酯： 苯二异酸酯，甲苯二异酸酯醛：- 氯：- MonomerMonomer：FunctionalityandNumberof 成新键的数目，numberoffunctionalities，f表示nH2N R COOH H HN R n

nHOOC(CH2)4COOH n CO(CH2)4COOCH2CH2OnH+(2n-1)H 聚合物，如n ORCO +(n-1) 2HOCH

OOO*CCO* 聚酰胺-6（锦纶-TypicalCondensationPolymers

COOOC

O OH+O OOO3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation 单体 二聚体

n--聚体 3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation OH

+Hk K [OCO][H2O]k- 3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation 己二酸300～320庚二酸290～310辛二酸340～360壬二酸320～340己二酸300～320庚二酸290～310辛二酸340～360壬二酸320～340 H(OROCOR`CO)m(OROCOR`CO)nH

3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation H(OROCOR`CO)m(OROCOR`CO)n (OROCOR`CO)qH(OROCOR`CO)m HO(COR`COORO)q

(OROCOR`CO)n(COR`COORO)p3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation

产 度

3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensationN：为t时残留的羧基或羟基数 N0－

N0

p[M]0[M 或[M(1p)[M3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation Xn

＝N

P=N0－N=－ XP=－Xn

Xn

－ 所以，当P0.9，XnXP=0.99~Xn

=100~

0.00.20.40.60.8Xn p3.EquilibriumLinearCondensationMechanismMechanismofLinearCondensation 例：a/b＝则：pa＝100％时，pb＝例：2

+H2O 4.KineticsofLinearCondensationTheoryTheoryofEquivalentActivityof 4.KineticsofLinearCondensation k OH+ OH+

+ +4.KineticsofLinearCondensation Rp=－d[COOH

=k3[C+(OH)2][OH [C+(OH)2][A－

[C+(OH

k1[COOH][，K=k2，

[COOH][

2]k

2[代入R=

d[COOH

=k1k3[COOH][OH][ k2[4.KineticsofLinearCondensation KHA

[H+][A－][HA]d[COOH

[A－] k1k3[COOH][OH][H＋] Rp=

4.KineticsofLinearCondensation ，并令kd[COOH k1k3[COOH][OH][H＋] Rp=

– –

=kC

= = P=1N羧基数用羧基浓度C代替，C＝C0(1－P)4.KineticsofLinearCondensation 1－1－P=2Ck20P～tXn

－

0n ～t0n

—)2—)2以—t2K4.KineticsofLinearCondensation d[COOH k1k3[COOH][OH][

–

=kC3+ka[H+]C2Rp=

–

=(kC+

a[H+作为催化剂，[H+]不变，且可忽略自催化，即kaH+并令k`ka[H+] –

=

4.KineticsofLinearCondensation

=C＝C0(1－P)1－

=k`C0t+

–Xn=k`C0t+—

Xntk`k4.KineticsofLinearCondensation COOH+

+ tCCCC

—

=1C

1(－C)2

=k

(－C)n 4.KineticsofLinearCondensation PN0－NC0－ C

CC0－P)1（C0=引入平衡常数：K＝k1/k-1，k-1=k1/K

dP=k dt=

－P－P2－P)Pnw 4.KineticsofLinearCondensation 密闭体系：在可逆缩聚反应中，平衡常数对P和 dP=k

PP2KP KP=

Xn= = = KK+ KKXnXn K+

4.KineticsofLinearCondensation 平衡常数p平衡常数p125KP K+KXXn K+4.KineticsofLinearCondensation dt=

－P)Pnw K

－P)2

K ∴Xn=－

(－P)2 P1 PXXnKP1（XnK线型平衡缩聚反应方程

>4.KineticsofLinearCondensation K温度

Xn= P4.KineticsofLinearCondensation — nW(mol/4<4×10－4（高真空度<4×10－2（稍低真空度5.MolecularWeightandDistributionofLinearCond.EffectsonMolecularWeightandDistributionofLinearCond. 控制方法：端基 5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond. r q=(Nb－Na)/2=Nb－Na=∴r

Na/1

r-q—下一步要求出聚合度Xn与r(或q)、反应程度P5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.设官能团a的反应程度为则aNaP（也是b官能团的反应数a官能团的残留数为b官能团的残留数为a、b官能团的残留总数为（Na＋Nb－2NaP）/体系中结构单元数等于单体分子数（Na＋Nb）/(Na＋Nb)/ Xn=( = ＋－2—表示了Xn与P、rq

(P5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.＋r2rPP当原料单体等当量比时r=1（q=0）Xn

2(－

1+ Xn

5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.＋r2r＋r2rPP 例题：当过量摩尔百分数0.1r=1000/1001和100/在100%的反应程度下，根 Xn(1r)(1Xn 2001和99%的反应程度下,Xn 95.3和98Xn 48.8和

Xn

11r2r5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.r

q=2

=

=

Nb－NaP= 2(Na－NaP)2

=体系中的结构单元数（即单体数）(Na＋Nb)/2＋NcNa5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond. Xn=

2 =(2)2NaP=＋r2rPrq5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.r

q体系中的大分子数：Na-NaP体系中的结构单元数（即单体数）：Na＋r2rPP—三种情况都说明，XnP、r(q)形缩聚中，要得到高分子量，必须保持严格的等当量5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.例题：生产尼龙－66，想获得Mn13500的产品，采用己二酸过量的办法若使反应程度P0994，试求己二胺和己二酸 CO(CH2)4CONH(CH2)6NHn

=

Xn

1350146 1185.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond. 当反应程度P=0.994时，求r值 ＋r2rPP

＋r1+己二胺和己二酸的配料比：rq+118=q+2(0.994)

q=5.05.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond. P＝起始反应的羧基数＝－P

＝起始反应的羧基数＝ 总乘积为：Px－1(－P)5.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond. Nx=Px－1Nx=Px－1－P)N

反应程度 N1数Nx=Nx=N1－P)N0－若起始单体总数为N0，则反应程度为PPNx=Nx0－P)2Nx=Nx0－P)2

1

0N1=N0(－P)25.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond. xM0 xN0Px1－P)2Wx=xPx1－P)2W00W=Wx=xPx1－P)2W005.MolecularWeightandDistributionofLinearCond.EffectsEffectsonMolecularWeightandDistributionofLinearCond.

NxNpx1(1wxxNxxpx1(1p)2N0

Xn1(1Xw11分子量分布宽度：Xw1

p许多逐步聚合的Xw实验值接近于2，间接证明了理论分布 5.MolecularWeightandDistributi