1
Applications oriented polymer design – structure – property relationship
Brigitte Voit
Leibniz Institute of Polymer Research DresdenHohe Strasse 6, D-01069 Dresden, [email protected]
Dresden
Polymers? Everywhere in your daily life
2
Some applications of polymers
Production of polymers
3
annual world consumption of organic polymers 1990 i n Mio tons
heating (wood, char coal) 600construction material (wood) 1300paper/card board 400plastics (incl. additives) 100fibers synthetic 15,9
Rayon 3,2cotton, wool, silk 21
rubber synthetic 9,9natural 5,2
thickener, natural and synthetic 11,1(no food)
adhesives and sealing 5,5resins 1,0synthetic polymers total 140 million tons
Specific products 1997in Western Europe in Mio. tons:PS: 2.1, PVC: 4.5, PP: 3.8, PE (HDPE + LDPE): 6.6
Polymer production/consumption
1980 2001 2010
consumptionkg/person
1960 1970 1980 1990 20001950
200 000 kt
150 000
100 000
50 000
0
world
West Europe
Germany
Production in kt
app. 140 Mio t/a polymersworld wide used (1990)
(compare 1300 Mio t/a wood used as construction material)
Structure and properties
Polymer properties - determined by structure and design
thermal properties wearing temperature, softening temperatureheat distorsion temperature, degradationtemperature
mechanical properties strength, hardness, moduluselasticity, toughness
density weight -> compact, foamed, filled...
surface properties (non)adhesion, roughness, haption
optical properties transparency, refractive index, color
durability oxidation stability, fatigue resistancechemical resistance
processability solubility, flow properties, solution and melt viscosi ty
functionality acid, base, complexing groups, biological active a.o., water soluble, amphiphilic, photo activity
inherent properties e.g. LC, NLO, conductivity a.o.
price!
4
Polymer characterization: summary on methods
- structure characterizationspectroscopic methods: NMR (Nuclear Magnetic Resonance), IR (Infrared Spectroscopy), UV, x-ray structure analysis-> structural units (chemical repeating units), end groups, insertion of the monomers, side reactions, tacticity, copolymer composition, determination of conversion, quantification of polymer analogous reactions, polar interactions, ordered arrangements, crystallinity (extent, orientation)
- molar mass determination (M n, Mw, Mz)
absolute methods for Mn- end group quantification- membrane and vapor pressure osmometry- boiling point elevation/ freezing point depression
absolute methods for Mw- light scattering- ultracentrifuge (Mz)
relative methods- viscosimetry- GPC (gelpermeation chromatography or size exclusion chromatography = SEC)
- thermal properties- DSC (Differential Scanning Calorimetry)
->glass transition temperature Tg, melt temperature or region (incl. heat enthalpy); relaxation phenomena, LC phases, reaction kinetics
Polymer characterization
polymer characterization: summary on methods (2)
- thermal properties (cont.):- TGA (thermogravimetric analysis)
-> thermal stability, degradation behavior- DMA or DMTA (dynamic mechanical (thermo) analysis)
-> relaxation processes, modulus, Tg, reaction kinetics (e.g. crosslinking) dependingon T and frequency or shear
- mechanical properties- DMA or DMTA
response of the material under stress, T and frequency dependence(storage modulus, loss modulus, loss factor (tan δ))-> relaxation processes, modulus, reaction kinetics, heat deflection temperature
- TGA/DMTA: thermal stability, heat deflection temperature- Stress-strain experiments
-> elasticity modulus (E modulus), strain at break, tear resistance, stress crystallization- Compression and tension experiments
-> compression modulus K, stiffness, - Crack test/impact/bending test
-> toughness, notch impact resistance, impact hardness, cracking resistance, crack formation, tear resistance, flexural modulus
- Rheology studies (melt viscosity)flow properties T and frequency dependent, pressure dependent-> complex melt viscosity, shear modulus G; melt flow index
- Further testing: e.g. scratch hardness, gloss, adhesion, turbidity, friction, conductivity, color and many others
Polymer characterization
5
Structure and properties
100 150 2000
2
endo
->
Temperature (°C)
partial crystalline polymer
amorphous polymer
reactione.g. curing
melting
recrystallization
Tg
Tg
Thermal properties: - Tg (glass transition), - Tm (melting transition), - Tdec (degradation temperature)- Trecryst (recrystallization T)- Treact (in case of any reaction)- several other transitions of second order
(relaxations)
Differential Scanning Calorimetry(DSC)
���� start of weight loss („onset“)
���� „Knee point“, „temperatureinflection point“
���� Extrapolated onset
���� Temperature of max. decomposition rate
���� 5% weight loss
TGA:• gives only information regarding degradation into volatil es• no information on loss of mechanical properties (often m uch earlier) which would be
important ot determine the so-called „Dauergebrauchstemp eratur“• mechanische Eigenschaften gehen oft schon beim Poly merabbau in • important Tdec depends on atmosphere (e.g. air N 2), particle size and heating rate
Dynamic Thermogravimetry (TGA)
0
20
40
60
80
100
100 200 300 400 500 600 700
Probentemperatur [°C]
rela
tive
Mas
se [%
]
3
3
1 2 5 4
1 2
5
4
Polymer characterization
6
Polymer characterization
secondary transition
glass transition (main transition)
entropy elastic behavior (rubber plateau)
viscousbehavior
glass transitiontemperature
energy elasticbehavior
G for duromerm
odul
usG
loss
fact
orta
nd
G for a partially crystalline thermoplaste
mechanical behavior/properties- modulus (storage/loss, shear, compression ...)- relaxations (Tg)- flow
DMTA analysis(dynamic mechanical (thermal)analysis)
Polymer characterization
1. SAN, high modulus, very stiff
2. ABS, high modulus, very brittle
3. PC, tough material
4. PA, high modulus, yields, tough
5. PP, lower modulus, very tough, yields strongly
6. filled vulc. NR/BR, low modulus as all rubbers, high strain
7. PU-elastomer
Stress-strain curves for different materials
strain
s tre
s s
stress-strain measurements
- E-modulus/Youngs modulus- elongation at break- stress at break
7
1. Variation of molar mass and molar mass distribution- low molar mass (oligomere) - high molar mass (polymers) - ultra high molar mass
- narrow or broad molar mass distribution- monomodal - bimodal - multimodal
=> change of material properties Pn
How to control (fine tune) the properties
Thermal and mechanical properties are dependent on mola r mass up to a critical molar mass (entanglement molar mass M c). Then a plateau value isreached. Entanglement molar mass is dependent on monomer structureand flexibility (segment mobility) of the polymer chai n.
Mc: PE ca. 20,000 g/mol PET ca. 5000 g/mol
���� very high modulus requires very high molar masses -> UHMW -PE for high tensilestrength fibers
���� high molar mass -> high solution and melt viscosity (pro blems with processing)
���� narrow molar mass distribution -> defined dissolution and viscosity behavior
Mc
Tg
Molar massdistributions
Structure and properties
2. Changes in architecturelinear, branched, star like, crosslinked, dendritic a .o.
BBBBBBBB
BB
BB
BB B B
B
BB
B
B
BBBB
BB
BB
B
B
B
BBBBB
BB
BB
BB
B
B BB B
Linear polymers:can exist as coils (amorphous) or in ordered arrang ement of the chain (crystallization)disadvantage: at high molar mass -> high viscosity
Branched polymers:lower tendency for crystallization, lower viscosity
Star polymers/comb polymers:low tendency for crystallization, low dependency of viscosity on molar mass
Crosslinked polymers:insoluble, swellable, elastic or very hard (elastom ers, duromers), crosslinking density can be controlled
Dendrimers:globular, highly functional polymers, exact control of molar mass and dimension, specific viscosity behavior
linear
short chain branched
star
comb polymer
network
dendrimers
Structure and properties
8
3. Variations in composition- Homopolymers from different monomers
Monomers and the type of polyreaction (polymerizatio n, polycondensation, carbon main chain versus ester or amide linkages) determine mainly the mater ial propertiesOlefins: aliphatic carbohydrate,ordered, high cryst allinity, low solubility and thus high stability ve rsus organic solvents, high mechanical properties, relative soft materials , limited thermal stabilityStyrene: high hardness and strength, brittle; butad iene: low T g flexible; acrylonitrile: chemical resistance, low s olubility,Polyesters, polyamides: exhibit H-bond -> crystalli zation, high mechanical strength
- copolymers: random, alternating, blocky- star copolymers, graft copolymers
Copolymerization allows the combination of different repeating units and thus the combination of different properties!Since most homopolymers are not miscible copolymerization is a necessary alternative to blend formation to combine material properties
Copolymerization allows also controlof architecture
Structure and properties
n = ( )n( )n = n
Monomer A
Monomer B
graft copolymersstar copolymers
alternating random (statistic)
block structure
Examples for copolymers - combination of properties
Styrene-butadiene copolymers - combination brittle(h ard)-flexibleMaterial properties depend on monomer compositionlow % butadiene -> impact modified polystyrene (alm ost transparent)star polymers with short butadiene blocks -> Styrol ux (transparent and tough)> 60% butadiene: elastic properties, opaque elastom er (rubber) (SBR)
Acrylonitrile-butadiene-styrene copolymers - combina tion brittle(hard)-flexible-chemical resistance(graft copolymer)Copolymer could be optimized as material for casing, kitchen ware, trays a.o.
Vinylalcohol-vinylacetate copolymers - combination wa ter soluble - water insolubleDesign of emulsifying and stabilizing propertiespolymeric surfactants
Styrene-vinylalkylpyridinium-copolymers - combinatio n polar-unpolarDesign of phase behavior, amphiphilic polymers, micelle formation
Polyurethane-polyol copolymers - combination hard-sof tThermoplastic elastomers, phase separated, Polyurethane hard phase acts as netpoint
x yx y
x zCNy
O x yOHCO
CH3
x
N
y
“
R
Structure and properties
9
4. Variation of internal structure- primary structure: configuration -> tacticity- secondary structure (coil rod)- tertiary structure (amorphous, crystalline, partial crystalline, liquid crystalline)
coil(amorphous)
worm like rigid rod
highly crystallinesheet structure
partial crystallinee.g. TPE
liquid crystallinepreferred orientation of molecules or dipols
z.B. Polypropylene: CH2 CH
CH3
isotactic syndiotactic atactic
Structure and properties
determine strongly thermal and mechanical properties!as well as optical properties!
Polymer crystalline Tg in oC Tm in
oC
i-PP yes - 7 168-178
a-PP no -13 -
a-PS no 100 -
s-PS yes 100 270
i-PS yes 60 230-240
HDPE yes - 134
i-PMMA no 38 -
a-PMMA no 105 -
s-PMMA no 105 -
PET yes 70 265
Nylon-66 yes (50) 265
polyoxymethylene yes - 181
polysiloxane sometimes -120 (app. 4-20)
natural rubber no -80 -
SBR no app. –20 bis +10 -
examples for thermal properties of amorphous and crysta lline polymers
Structure and properties
10
Transparent polymers
Basic requirement: amorphous material or size of crystallites < wavele ngth of visible light
Polycarbonate: fully amorphous, tough (used for win dows, glasses, CD’s)
PMMA: atactic material (prepared radically) fully am orphous, brittlemostly impact modified with polybutadieneisotactic PMMA (prepared anionically) crystalline an d thus opaque
PS: atactic material fully amorphous (prepared free radically), transparent , very brittle impact modified with butadiene as comonomer ( Styrolux)
syndiotactic PS, highly crystalline, hazy
MABS: copolymer from 4 monomers: MMA, styrene, butad iene, acrylonitrile, transparent, amorphous
PET: aromatic, aliphatic polyester (used for bottles ), crystalline but relatively transparent since size of crystallites < 250 nm
PP: in thin foils it looks transparent, crystalline, but size of crystallites can be controlled by processing and processing aids
6x + Si O SiCl
Cl
Cl
Cl
Cl
ClPS PB Styrolux
Structure and properties
Principles to increase the inherent temperature stability of polymers (T g, Tm, Tdec)
- increase of chain rigidity, e.g. high aromatic conten t, ladder like structures
- possibility to form H-bonds e.g. in aramides (is processed in solution from LC p hase)
- fluorinatione.g. Tm ( PE) = 134 oC Tm (PTFE) (polytetrafluoroethylene) = 327 oC
- introduction of heteroaromatics, e.g. polybenzoxaz oles
- introduction/increase of crystallinity by increasin g the orientation/order of the chains(tacticity, H-bonds, no bulky substituents, recking process)
- avoid aliphatic, flexible, non crystalline chain s egments or chain kinks
- low free volume and polar groups increase Tg
poly-1,2-butadieneR ⊕ ⊕
Ox
T
T (2000 C)
carbon fibers
Structure and properties
11
Examples of high performance polymers
O O C
O
n
O O S
O
nO
C C
OO
n
NN
O
OO
O
S
n
n
O
N
N
O
n
Ph
O
n
Ph
Ph
poly(aryl ether ketone) polyaramide
poly(aryl ether sulfone) poly(phenylene sulfide)
aromatic polyimide
poly(phenylene oxide)
poly(benzoxazole)
poly(para-phenylene)
O C
O
O C
O
n
liquid crystalline polyester (Vectra)
N N
n
HH
PEEK
PPO
PESPPS
PBOx
PPP
Structure and properties
Characteristics of poly(ethylene terephthalate-co-oxy benzoate)
orientation of the molecules forced by shear during melt pr ocessing e.g. in fibers
n
OC
OO O
C C OCH2CH2O
m
POB
Structure and properties
12
Structure model for fibers from thermotrope LC polymers
Sawyer, L. C., M. Jaffe (1986)
Structure and properties
Structure Typ Td [N2]* Td [Luft] #
AC 720 °C
AC 660 °C (675 °C #) (570 °C?)
AC 590 °C
AC 535 °C (560 °C #) 700 °C
F F
FFn
n
*TGA, extrapolated onset#TGA, temperature inflection point
n n
Polyphenylene
Structure and properties
n
13
Composites and reinforced plastics
Polymers are often filled or reinforced with filler s and fibers whereas particulate fillers are used i n composites and fibers are used in fiber reinforced plastics (or compound materials). The polymer iscalled „matrix“ and can be a thermoplaste, elastome r or duromer.
Composites:Addition of particulates (chalk, clay, silica, carb on black, metal powder, short fibers a.o.) improves certain material properties (e.g. heat deflection temperature, mecha nical strength, abrasion, conductivity). Filled the rmoplastes can still be processed in the melt. Sometimes more than 50% filler are added. Blends of 2 or more differen t polymers are not considered composites.
new developments: NanocompositesThe filler (sheet silicate, carbon tubes, rigid rod polymers) have in one dimension a diameter of only a few nanometers in combination with a large aspect ratio (ratio len gth to diameter) -> special material properties e.g. higher thermo s tability, good barrier properties.
Fiber reinforced plasticsone uses short fibers (mostly glass, e.g. for PP, P A), long fibers (glass, thermoplaste fibers PP),non-woven (from thermoplaste fibers PP), fabrics (gl ass fibers, aramide fibers), laminates (glass fibers ,carbon fibers).For fabrics (prepared by winding technique) and lam inates mostly duromeric matrices are used. In laminates different layers of fabrics are twiste d by 45 oC to allow reinforcement in two dimensions. One obta ins light, high performance construction materials.
The fiber content increase heat and form distortion resistance as well as mechanical strength.
Structure and properties
Mechanical properties
- high tensile strength
-> fiber reinforced composites
-> High performance polymers
tensile modulusnormed on PP
Addition of fillers (fibers, inorganics a.o.) increases heat deflection temperatureof polymers
material pure short fiber
reinforced
glass mat
reinforced
laminate
reinforced
PE 1 7
PP 4 9
PS 6 15
polyester 2-10 15 25 70
epoxy resin 5 15 30 60
phenol resin 7 18 25 60
Zn 41
Al 33-47
Mg 34
steel ca. 32
property LC-
polyester
polyimide PPO polyaramide PBOx carbon fiber glass fiber
tensile strength in MPa 140-240 105 92 3500 5700 2200-7000 900 - 2000
degradation Temp. in oC
(at 5 wt% weight loss)*
240 220-350 400 300 >500 > 1500 > 1500
Structure and properties* or heat deflection temperature
14
Polymer characterization
polymer hardnessN mm-2
phenol resin composite to 200
urea resin composite to 150
melamin resin composites to 200
polyester resin (cured) to 200
epoxy resin (cured) to 200
fluoro-polymers 30 ... 70
polyacetale to 140
polyamide to 100
polycarbonate to 100
polymethylmethacrylate to 200
polyethylene 10 ... 65
polypropylene 60 ... 75
polystyrole to 120
polyvinylchloride to 120
PVC, impact modified 30 ... 100
Examples for hardness Examples for tensile strength and he at deflection T (HDT)(or Tdec)
polymer tensile strength MPa HDT or Tdeg. in oC
PP 37 90
PS 55 86
nylon 6,6 77 235
PEEK 92 250
PBox 5700 > 500
Vectra (LC polyester) 140-240 180-240
Xydar (LC polyester) 126 337
Ultem (polyetherimide) 105 217
Kapton (polyimide) 117 > 400
polyX1000 (PPP) 170-240 170 (Tg)
New (improved) fillers
Nanocomposites - layer silicatesin-situ polymerization reactive proces
higher potential (lower costs)
only for some special cases (e.g. anionic PA)
possible improvements - mechanical properties- thermal stability- barrier properties- reduced flammability- improved optical properties- reduced abrasion- ion conductivity and others.....?
problems:- costs- modification of silicate necessary, new modifier- intercalation and dispersion needs to be improved
first high expectations somewhat reduced
IPF, NC with PP
Carbon NanotubesNanoparticlesoptics, hardness, toughness, mechanics, abrasion, surface properties....
http://www.research.ibm.com/nanoscience/S. Sinha Ray, M. OkamotoProg. Polym. Sci. 28 (2003) 1539–1641
biodegradable PLS-NC?
15
New functional fillers - Carbon Nanotubes
50 min -1 in DACA minitruder 150 min -1
10 -2 10-1 100 101 102102
103
104
105
106
PE 4261A
PC-2NT
Blend 45% PC2NT/55% PE
(150 min-1
)
kom
ple
xe V
isko
sitä
t Iη
* I (P
a s
)
Messfrequenz ω (rad/s)8,80 104PC-2NT
1,50 1015PE
5,31 106PC-2NT / PE = 60/40
4,85 106PC-2NT / PE = 50/50
6,33 106PC-2NT / PE = 45/55
1,65 106PC-2NT / PE = 40/60
Elektrischer Volumenwiderstand
(Ohm cm)
Zusammensetzung
melt rheologySignificant reduction of elect. resistance incocontinous region (C-2NT)
2 mm
PC-2NT/PE = 40/60 Vol%
Cocontinuous blends from PC-2NT and PE
IPF, Pötschke
Nanoparticles
inorganic nanoparticlessol-gel processesorgano-hybridssurface functionalization/graftingstabilization/dispersion
need for processesneed for special stabilizers
organic nanoparticlesbetter size controlbetter control of particle distributionsmaller particlessurface functionalizationmulti compartment particles
new (improved) processes (miniemulsion)new stabilizersfunctional(reactive) stabilizers
e.g. Ormocere®(FhG Inst. für SilicatforschungWürzburg)INM, Saarbrücken
http://www.mpikg-golm.mpg.de/kc/landfester/
www.isc.fraunhofer.de/german/ portal/tech_15.html
Ormocer particle, 153 nm
Landfester:Polyacryamide latex obtained by inverse miniemulsion polymerization.
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5. Control of morphology
Homopolymers with different chemical structure are m ostly not miscible -> phase separation
The polymer with the lower content forms the disper sed phase whereas the the other polymers forms the continuous matrix .
The miscibility or the size of the dispersed phase (100 nm to 5 µµµµm) is determined by interactions between the two polymers ( ππππ, ππππ or ionic interactions or H bonds) as well by the ad dition of compatibilizers . Compatibilizers are block or graft copolymers , which are located at the interphase. High interac tion is necessary for good mechanical properties.
Interesting morphologies (nano structures) can be achieved in well defined block copolymers depending on the comonomer content. Size of the structures 20-100 nm!
withoutcompatibilizer
withcompatibilizer
< 20 % 20-30 % 30-70% 70-80 % >80 %
e.g. anionicallypreparedblock copolymers(PS-PB)
Structure and properties
Blends
Structure (morphology) property relations
Morphology control!
withoutcompatibilizer
withcompatibilizer
Compatibilizer
high potential!blends can substitute use of blockcopolymers
ppcl.chungnam.ac.kr/lecture/ morphology/12/crystal12.htm
HIPS
---> compare also cooperationBASF -IPF (Weidisch, Stamm)
source: BASF product information
17
Polymer Morphology
www.polynano.com/Results/ HomepageExp.htm
www.chemie.uni-hamburg.de/ pc/sfoerster/forsch.html
mikto arm stars
Block co- and terpolymersStar polymers
need of controlledsynthesis
anioniccationiccontrolled radical polymerization
potential?
Morphologies of Styrene-Butadiene—t-butylmethacrylate triblock copolymers
OsO4
250 nm
OsO4
250 nm
S19B57T24100
RuO4
250 nm
OsO4
250 nm
OsO4
250 nm
OsO4
250 nm
OsO4
250 nm
OsO4
250 nm
S32B35A33121 S23B50A27190
S19B57A24127 S11B80A0995
S27B29T44146 S16B50T34147
S10B76T14102
V. Abetz et al. Macromol. Symp. 2002, 177, 139 Prof. Volker Abetz
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Control of morphology - Selforganization
Interesting morphologies (nano structures) can be achieved in well defined block copolymers depending on the comonomer content. Size of the structures 20-100 nm!
< 20 % 20-30 % 30-70% 70-80 % >80 %
e.g. anionically prepared block copolymers (PS-PB)
www.chemie.uni-hamburg.de/ pc/sfoerster/forsch.htmHelmut Schlaad, Habilitandenworkshop Juli 2003
amphiphilic blockcopolymersmicellar structures
Atom Transfer Radical Polymerization
Chemistry
Materials
NNCuN N
kact ~ 1 M-1.s-1
kdeact ~ 107 M-1.s-1
X Cu
NN
NNPn +
+ M
kp ~103 M-1.s-1
kt
Y
x xx
x
xxxxx
xx
xxxx
Multifunctional
Homopolymers
Gradient Copolymers
Block Copolymers
N. V. Tsarevsky, S. Jia,T. Kowalewski
MolecularBrushes
K. Beers, S. Sheiko,M. Moeller
X
XX
X X
X
HybridNanoparticles
J. Pyun,T. Kowalewski
Flat PolymerBrushes
P. Miller, G. Kickelbick,T. Kowalewski
-X
-X-X
-X-X
xxxxxxxx
x x xxxxxxxx
x x
- X
X
X
XX
X
XX
RX
N. V. Tsarevsky, W. Wu,T. Kowalewski
+
Provided by Nicolay Tsarevsky
Carnegie Mellon UniversityKris Matyjaszewski
19
S. James, Queens Univ., Belfast
R. Haag, D, Berlin
Srinivasarao , Georgia Inst. Tech.
R. ZubarevRice Univ.Houston
Self assembly
Surface polarity (surface energy) determined by contact an gles
θθθθ < 90°: hydrophilicgood wetting
θθθθ > 90°: hydrophobiclow wetting
θθθθ = 0°: hydrophiliccomplete wetting
72.0 Water
40.5 Polyethyleneterepthalate38.5 Polymethylmethacrylate (PMMA)33.3 Polyethylene29.7 Polystyrene
19.5 Polysulfone19.0 Polypropylene18.0 Polytetrafluorethylene
6.0 monolayers of perfluorinatedcompounds
C O
O
CH2
O
CF2
CF3
20
Application of hydrophobic polymers
HydrophobicMaterials
water and oilrepellent
low long term adhesionof proteins, microbesalgae, antifouling
antifouling-properties
bioinert/biokompatibilität
→→→→ non toxic protective paints (ships)→→→→ antiadhesive coatings (pan)
→→→→ Textile finishing→→→→ long term outdoor paints
→→→→ Implantates→→→→ Membranes
Surface modified polymers in cars
body paint:high glossself cleaning(hydrophobic)
bumpers:paintability (hydrophilic)self cleaning (hyrophobic)
light coverageself cleaning(hydrophobic)
Adhesives!hydrophilic
21
Self cleaning (Lotos)-Effects
W. Barthlott (Uni Bonn), 1. Patent 1994
macro-roughness 10-50 µmmicro-roughness 0.5-5 µm
for materials science
combination of roughnessand surface energy
paint Lotusan, Fa. Ispo
Selfcleaning effect using semifluorinatedpolyesters and blockcopolymers
D. Pospiech, W. Kollig, S. Schmidt, K. Grundke; Kooperation zu TU Dresden
needed:1) subtrate with high surface roughness2) low surface energy of polymer3) low contact angle hysteresis
pCH3
CH3
CH3
CH3
(CH2)10(CF2)10F
C
O
O
C
O
O SO2 O OO
n
OO
(CH2)10(CF2)10F
C
O
O
C
O
m
freesurface energy: 9 mJ/m 2 15 mJ/m 2
polymer film on structuredaluminum
contact angle: 159.6° / 157.0° contact angle: 158.2° / 155.7°
22
Two-level structured switchable polymer films
Pin -like PTFE substrate with grafted PS-P2VP mixed brush
Rolling of water drop on PTFE with the grafted PS-P2VP binary brush after exposure to toluene (h)(h) and wetting after exposure to water (i).(i).
h
i
ultrahydrophob fully wettable
Polymer foams
density of polymers app. 0.9-1.5 g/cm 3
polymeric foams app. 0.01-0.2 g/molglass app. 2.6-4.0 g/cm 3
aluminum app. 2.7 g/cm 3
iron app. 7.9 g/cm 3
foams
Polymers can be foamed via added blowing agent or via ch emical reactions(e.g. polyurethane foams, Styropor).By this the volume can be expanded by a factor of 1 00!
blowing agents: (fluoro carbons), pentane, carbon dio xide, nitrogen
polyurethane foams: polymers crosslink upon foamingNetwork density and the monomer/oligomer structure definethe foam structure (hard or soft foam)components: di- and trifunctional isocyanates, polyo ls, partially diacids
R1 COOH + OCN R2 R C
O
N
H
R + H2O
Structure and properties
23
Design of polymer properties - foaming
Polyurethan foams
cutting along
foam direction
cutting accross
foam direction
HO OH + OCN-R-NCO
P O-C(O)-NH-R-NH-C(O)-O P
+ R(OH)3 (crosslinker)+ some water (foaming agent)
Functional Polymers
Daily life
cleaning agents, detergents
water purification
paper production
textile industry/finishing
leather treatment
cosmetics
pharmaceuticals
food
hygiene
.......
coatings, resins
Daily life
cleaning agents, detergents
water purification
paper production
textile industry/finishing
leather treatment
cosmetics
pharmaceuticals
food
hygiene
.......
coatings, resins
High Tech
data storage, communication
sensors, actors
microelectronics -> photo resins
conducting polymers, LED, NLO
nanostructures
nanocomposites
surface finish
medicine
.......
High Tech
data storage, communication
sensors, actors
microelectronics -> photo resins
conducting polymers, LED, NLO
nanostructures
nanocomposites
surface finish
medicine
.......
24
microscopic picture of a hairwith and without conditioner
strong hold by bridging
composition of hair spray
cosmetics: hair treatment
CH2 CH CH2 CH
CONH2 CONH(CH2)3N+(CH3)3Cl
-
cationically modified polyacrylamide
water treatment: coagulants
Problem: in water treatment plants and industrial wast water the water is often heavily loaded with finely dispersed organic and inor ganic material
25
CH2 CH CH CH
COOH COOHCOOH
Incrustation inhibitor:acrylic acid/maleic acid copolymerecomplexes and stabilizes „Kalk“
cotton fiber washed with (right) and without (left) Incrustion inhibitor
heating tubes with and without incrustion inhibitor
detergents, water additives
function of a superabsorber:highly swellable polar polymer networkbased on polyacrylic acid
cosmetics: diapers
polyelectrolytes = charged polymers
26
Application of hydrophilic polymers - hydrogels
Dirk Schmaljohann 2/2002; #51
Hydrogels
contact lenses
Tissue Engineering
→ Polymer Scaffoldsfor cell growths
Substrate for cell culture
Source: http://www.augenkontakt.at/
wound protection
Drug delivery→ defined drug delivery
upon degradation of the matrix
cosmetics
Source: http://www.unipublic.unizh.ch/magazin/gesundheit/
2000/0032/
Source: http://www-cuk.med.uni-rostock.de/achir/wunden/wu_auf.html#gele
