Polymer Chemistry - gxu.edu.cnhxhg.gxu.edu.cn/polymerChemistry/uploads/courses/10.pdf · Polymer Chemistry GuangxiUniversity ... Ex., friction materials (brake lining, transmission

Polymer Chemistry

Guangxi University School of Chemistry & Chemical Engineerin

g

Li Guang Hua (李光华)

Lab：材料楼—409#，321# E-mail : [email protected] phone: 15978133590

mailto:[email protected]

CHAPTER 10

Thermosetting Polymers :

Fusible & soluble polymer Crosslinking

Infusible & insoluble polymer Thermosetting polymer

Thermoplastic polymer

Guangxi University School of Chemistry & Chemical Engineeri

ng

1. Phenolic Resins2. Amino resins

4. Epoxy Resins5. Polyurethanes

(1)

3. Unsaturated Polyester Resins

1. PHENOLIC RESINS (I)

Phenolic Resins (Phenolics) F

á Commercialization : in 1909 (Bakelite company)

Phenol-formaldehyde (PF) resins

O O O O


ng(2)

f = 3

OH OH

CH2OH

CH2OH

HOH2C

OH

CH2OH HCHO

OHCH2OH

CH2OH

HCHOHCHO

1. PHENOLIC RESINS (II)

OH

CH2OHHOH2C

OH

CH2OH+

OHCH2OH2CHOH2C

OH OHCH2HOH2C

OHCH2OH


ng(3)

CH2OH2CHOH2C

OHCH2HOH2C

OH

CH2HOH2C CH2OH

-HCHO

1. PHENOLIC RESINS (III)

Ø NovolacsConditions : formaldehyde : phenol = 0.8 :1

Catalyst : acid (H2SO4, oxalic acid)

OH

+ HCHO

OHCH2

OHCH2

CH2

OH

CH2

OH


ng(4)

Novolacs (MW : 700 ~ 1000)

OHOH

CH2

OH

CH2n

CH2

OHCH2

OH

1. PHENOLIC RESINS (IV)

Novolacs

OHOH

CH2

OH

CH2n

N

N

NN

Phenolic resin

Molding powder

Filler


ng(5)

N

N

NN

6 HCHO + 4NH3

hexamethylenetetramine Catalysis & crosslinking

1. PHENOLIC RESINS (V)

Ø ResolesConditions : formaldehyde : phenol = 1.25 :1

Catalyst : base (NaOH, NH3)

OH

+ HCHO


ng(6)

OHCH2HOCH2

OHCH2

CH2OH CH2

OHCH2OH

CH2OH

OHCH2OH

Resoles (MW : 500 ~ 1500)

Phenolic resin

Ø Properties of Phenolics

á Have good chemical and thermal resistance, dielectric strength, and dimensional stability.

á Most phenolics contain fillers or reinforcements

◎ General-grade phenolics are filled with mica, clay, mineral flour, cellulose, and chopped fabric

1. PHENOLIC RESINS (VI)


ng(7)

◎ Engineering-grade phenolics are reinforced with glass or organic fibers, elastomers, graphite

á Products made with these resins are inherently low in flammability, are creep resistant, and have low moisture absorption

á AdhesivesEx., the manufacture of plywood and fiberboard

á Coatings

Ø Applications of Phenolics

Ex., coatings on cans, drums, metal pipe, electrical insulation, varnishes, and metal primers

1. PHENOLIC RESINS (VII)


ng(8)

á PlasticsEx., printed-circuit boards, gears, cams protective, decorative surfaces

for tables and furniture, switches, pump housings, and cutlery handles

á OthersEx., friction materials (brake lining, transmission bands), foam insulation,

and carbonless copy paper

2. AMINO RESINS (I)

Amino ResinsFurea-formaldehyde (UF) resins

melamine-formaldehyde (MF) resins

N NNH2H2N

NH2

NH2 C NH2

O


ng(9)

N NH2H2N2 2

urea (f = 4) melamine (f = 6)

O CNH2

NH2

HCHO+

O CNHCH2OH

NH2

O CNHCH2OH

NHCH2OH

2. AMINO RESINS (II)

H2NCHNHCH2OHO

H

H2NCNO

CH23

H2NCNO

CH2 + H3O

N

N

N CNH2

OH2NC

O

CNH2O


ng(10)

N CH2OH H N CH2OH+

N CH2OH + NHOCH2

N CH2 + H2ON + HCHO

N CH2 N CH2OH + H2O

N CH2 O CH2 + H2ON

N CH2O H + NHOCH2

2. AMINO RESINS (III)

CH2 NH CO N CH2 NH CO NH

CO NH CH2 N CO NH CH2NHCH2

CH2 NH CO N CH2 NH CO NHCH2

CH2

O

Methylene bridge

Methylene ether bridge


ng(11)

CO NH CH2 N CO NH CH2NHCH2

N

N

N COCO

CO

NH CH2NH

NHCH2

N

Cyclic bridge

2. AMINO RESINS (IV)

Ø Properties of Amino Resins

á They are harder than phenolics but have somewhat lower impact strength and resistance to heat and moisture

á A distinct advantage of the amino resins over the phenolics is clearer and colorless

á The melamine resins have better hardness, heat resistance, and moisture resistance than the ureas


ng(12)

Ø Applications of Amino resinsá Adhesives (better performance than the phenolic resin)

Ex., the manufacture of plywood and fiberboard

á Melamine resins are used to produce colored dinnerware and dinnerware with decorative patterns.

á Amino resins also find extensive as automotive parts; the cheaper ureas are used as primers while the melamines are used as topcoats

3. UNSATURATED POLYESTER RESINS (I)

Unsaturated Polyester (UP) ResinsF

CO

CO

O

+C

OCO

O

+ 2HOCH2CHOHCH3

O O CH3 CH3O O

toluene sulfonic acid150 ~ 200oC


ng(13)

CC OCH2CHOO O CH3

CCH CHC OCH2CHOCH3O O

+ 2H2O

Unsaturated polyester (MW 1000 ~ 2000)

3. UNSATURATED POLYESTER RESINS (II)

OCCH CHCOO O

+ CH CH2

OCCH CHCOO O

OCCH CHCOO O

CH CH2peroxide

glass fiber

Glass fiber reinforced UP resin


ng(14)

Ø Properties & Applications of UP resinsá Have a good combination of resistance to softening and deformation

at high temperature, electrical properties, resistance to corrosion, weak alkalies, and strong acids and possess very good weatherability

á Construction :

á Transportation and marine industries:Ex., tub and shower units, building facades, and specialty flooring

Ex., truck cabs, auto body repair, and boat hulls

Ø Epoxy Resins

4. EPOXY RESINS (I)

CHOCH3

CH3

OHH2C CHCH2ClO

+ (n+1)(n+2)

COCH3

CH3

OCH2CHCH2H2C CHCH2

O OH OCH2CO

CH3

CH3

OCH2CH

n

NaOH aq-HCl


ng(15)

CH3 CH3n

n = 0 ~ 12 (MW = 340 ~ 3800)

O Ar O H2C CHCH2ClO

+ O Ar O CH2 CH CH2ClO

O Ar O CH2CH CH2

O+ ClO Ar O CH2 CH CH2

OO Ar O

O Ar O

4. EPOXY RESINS (II)

OCH2CHCH2 + NH2H2N R

RN

N

CH2 CH CH2

OH

CH2 CH CH2

OHCH2 CH CH2

OH

CH2 CH CH2

OH

CH3 CO


ng(16)

COCH3

CH3

OCH2CHCH2

OH+

CR

CO

O

O

COCH3

CH3

OCH2CHCH2O

COCH3

CH3

OCH2CHCH2

O

CRC

O

O

4. EPOXY RESINS (III)

Ø Properties of Epoxy Resins

á A wide range of products varying in properties and curing temperature are obtained for specific applications by proper selection of the monomers, additives, and curing agents.

á Possess high chemical and corrosion resistance, toughness and flexibility, good mechanical and electrical behavior, and outstanding adhesion to many different substrates


ng(17)

Ø Applications of Epoxy resinsá Adhesives

Ex., military (missile casings, tanks), aircraft (rudders, wing skins), automobiles (drive shafts), and pipe

á Coatings : Ex., marine, maintenance, drum, and can coatingsá Structural composites :

Ex., electrical and electrons industries (circuit-board substrate) á Laminates :

Polyurethanes (PU)F

5. POLYURETHANES (I)

OCN +R NCO R' OHn nHO R NHCO R' nOCNHO O

diisocyanate glycol polyurethane

CH3

NCO CH


ng(18)

2 NCO + R'' NH2H2N R'' NHCNHO

NHCNHO

urea linkages diamine

2,4-tolulenediisocyanate (TDI) methylene-4,4’-diphenyldiisocyanate (MDI)

NCO

NCO

OCN CH2 NCO

5. POLYURETHANES (II)

O

NH NH+ + OCN R' NCOCOO CO NH

C NHOR'NH C O

N COO

N CO NH

Allophanate

Biuret


ng(19)

NCO3N

N

N

O

OO

trimerizationcatalyst

OCN NCO OCN NH2H2O

NHCNHO

OCN NHCOOH-CO2

Ø Elastomers

5. POLYURETHANES (III)

CH3

NCO

NHCO B OCNH CH3

NHCO B OCNH CH3

NCO

O O

O O

CH3

NCO

NCO

+ B

excessR' OHHOR'' NH2H2N or


ng(20)

R'' NHCNHO

NHCNHO

NCOOCN

Crosslinked PU

C(CH2)4COCH2CH2OCH2CH2OOO

CH2CHOCH3

n nHHO HHO

B (MW = 1000 ~ 2000) :

poly(propylene glycol) poly(diethylene glycol adipate)

Properties of PU elastomersá Extremely good abrasion resistance and toughness, combined with

good elasticity and resistance to greases, oils, and solvents.

Applications of PU elastomersá Forklift tires & skateboard wheels

5. POLYURETHANES (IV)

¹

¹


ng(21)

Ex., bumpers, fenders, door panels, gaskets for trunk, windows, windshield, steering wheel, instrument panel

á Automobile parts

á Sporting goodsEx., golf balls, ski boots, football cleats

Ø Fibers

HO OH + OCN Ar NCO

OCN Ar NHCO

O OCNH Ar NHCO

O OCNHO O

Ar NCO

OCN Ar NCO H2N R NH2

B (MW = 2000 ~ 3000) excess

5. POLYURETHANES (V)


ng(22)

CNH Ar NHCNHOO

R NH CNH Ar NHCOOO

O

OCN Ar NCO H2N R NH2

(unreacted)

“Hard” segment “Soft” segment

spinning

Crosslinked PU fibers

á Polyurethane fibers have unusually high elasticityLightweight foundation garments and swimsuits

5. POLYURETHANES (VI)

Ø Foams

HO OH

á They do suffer from limited resistance to hydrolysis

H O


ng(23)

OCN Ar NCO

MW ~ 3000 excess

(unreacted)

OCN Ar NCO+HO OH

OH

or OCN NCO

OCN NH2

H2O

NHCNHO

OCN NHCOOH

-CO2

Flexible foams

Rigid foamsor

5. POLYURETHANES (VII)

Applications of PU foamsá Flexible foams

Ex., insulators, automobile crash panels, upholstery, bedding, carpet underlays, and synthetic sponges

¹

á Rigid foamsEx., commercial roofing, residential sheathing, and insulation for

water heaters, tanks, pipes, refrigerators, and freezers.


ng(24)

water heaters, tanks, pipes, refrigerators, and freezers.

Ø Coatings

OCN Ar NCO

excessOCN Ar NCO+HO OH

OHOCN NCO

OCN NH2

atmospheric moisture

O

OCN NHCOOH-CO2

5. POLYURETHANES (VIII)

“one-pot” coatings


ng(25)

OCN Ar NCO

(unreacted)NHCNHO “one-pot” coatings

á Have very good resistance to abrasion and solvent attack plus good flexibility, impact resistance and weatherability

Gymnasium and dance floors and bowling pins, in magnet wire coatings, etc.

á They can be applied by dip, spray, or brush and adhere well to a wide variety of materials

Documents

Polymer Chemistry - gxu.edu.cnhxhg.gxu.edu.cn/polymerChemistry/uploads/courses/10.pdf · Polymer Chemistry GuangxiUniversity ... Ex., friction materials (brake lining, transmission