Rheology of Polyols and Polyol Slurries for Use in Reinforced RIM

7 Rheology of Polyols and Polyol Slurries for Use in Reinforced RIM Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on March 2, 2018 | https://pubs.acs.org Publication Date: January 8, 1985 | doi: 10.1021/bk-1985-0270.ch007

1

2

1

1

M. M.CROSS ,A.KAYE ,J. L.STANFORD ,and R. F. T. STEPTO 1

Department of Polymer Science and Technology, University of Manchester, Institute of Science and Technology, Manchester,M6O1QD, England Department of Mathematics, University of Manchester, Institute of Science and Technology, Manchester,M6O1QD, England

2

Measurements with glass fibre/polyol slurries demon strate that fibre aspect ratio, l/d, is a dominating factor in relation both to attainable fibre loading and to slurry rheology. The fibre packing fraction, Φo, measured by sedimentation, is shown to be a rapidly decreasing function of weight average l/d. For fibres of different l/d the relative viscosity of the slurry at low rates of shear is a unique function of Φ/Φo, where Φ is the fibre volume fraction. The rheo logical investigation is based on novel instrumentation and techniques for measuring the viscosity of glass fibre slurries at shear rates from 1 to 10 s . Measure ments up to 10 s are based on modified cone and plate geometry, while the higher shear rates are attained with a capillary viscometer attached to a RRIM machine. Measurements on polyol blends with the RRIM viscometer show a slight fall in viscosity as the shear rate is increased to 10 s , but beyond this point there is a sharp rise in viscosity which is thought to be associated with boundary layer effects. 6

4

5

In

t h e RRIM p r o c e s s the i n i t i a l

dispersion

of

into

the mould.

This

for

of

flow.

of In

glass

tively fibre

little length

practical fibre

the

of

rheology has been

difficulties

involved

fibre

to

under

spherical

widely

particles

cylindrical

d.

One r e a s o n

associated with

the

studied

particles for

every

this

conditions behaviour

but or

stage flow

rheological

differing

the packing

have been e x t e n s i v e l y done f o r

at

the f i n a l

a sound knowledge o f

slurries

and diameter

I

is

reinforcing

compara fibres,

of

may b e t h e

r h e o l o g i c a l measurements

on

slurries. In

take

calls

fibre

the case

and d i s p e r s i o n

-1

rheological behaviour

from

properties

-1

-1

the present

a systematic viscosity

of

a glass

to

identify

in

a preceding paper

aspects

of

investigation

investigation

t h e more

fibre

important in

this

it

of

has not been p o s s i b l e

a l l

slurry,

the variables but an attempt

parameters.

volume

rheological behaviour

that

(J_) w e r e

have been

to

has been

Polyol

blends

used.

Three

under

might

affect made

as d e s c r i b e d specific

investigated.

0097-6156/85/0270-0097$06.00/0 © 1985 American Chemical Society

Kresta; Reaction Injection Molding ACS Symposium Series; American Chemical Society: Washington, DC, 1985.

98

REACTION INJECTION M O L D I N G 1.

A study

of

the

dependence slurry 2.

3.

relevant

machine,

of

rates

the

in

rate

shear

Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on March 2, 2018 | https://pubs.acs.org Publication Date: January 8, 1985 | doi: 10.1021/bk-1985-0270.ch007

example,

for φ

of

between

the

For ratios aspect

particles factor

for

is

is

previously

(])

filamentation in

several

noted

v-j

fraction

of

fibre

case

(v / 2

are

the

reality

be

a rapidly

empirically

φ

a

1/φ Equation

)[1

2 has

the

φ

0

is

results is

material

in

care

fibres

the

data.

completely

were

uniformly

detailed under

gravity.

medium by hand

taken

to

poured into

by v i g o r o u s

the

but

longer

be r e a c h e d .

w represents slurry,

level

the

the

that

measuring

tapping,

with to

ensure a

sedimentation

If

/(wp^)]"

the

glass

samples

fibres, The was

weight

packing

of

a function are

of

and the

clear

weight

average

basis

from Figure £/d.

and c a n be

w

workers

average

on t h i s

is

essentially

Other

number

represented

(&/d)

polyol.

CSG u s i n g

and i t

of

(1)

1

bimodal blends.

of

higher

relation

of

poor

is

(PB021)

was

was

(100-w)p

with

considerably

17um.

dispersed

+

aspect

(3).

be any comparable

equilibrium

the

determined

Isham

particularly

the

can be

φ

σ

is

in 2

that

seen

represented

equation

ο

a

For

and

0

sedimentation of

slurry

and a l s o

function

the

exists

voidage

1-φ ,

and by

work

equilibrium

decreasing function by

of

different

blends

dispersed

assisted

from

correlation is

0

the

0

volume

strand

CSG g r e a t

densities

that

and a c c o r d i n g l y the

in

was

the in

V l

materials

The

φ ,

HMG o f

to

present

volume V2-

c a r r i e d out

have contended 1.

there

close packing.

hexagonal close

(CSG), where

allowed for

fibre

were

(2)

polyol

stages,

calculated

-

of

fraction

appear

the

The

was

final

glass

and

mono-disperse

Figure

of

overall

σ

simu

machine.

is

bulk

determined by

the

was

0

Measurements

iTd

of

days were

Φ

(2,4)

the

integral

in

corresponding to

φ

Pg

glass do n o t

complete.

the

and a l s o

percentage

where

fraction

had a diameter

Sedimentation

slow

s~1, a

distribution

a state

and d a t a f o r

the

was

0

the

was

a RRIM

a volume

miscible

throughout

and i n

cylinder.

that

and φ

10^

using

a c o n d i t i o n of

(HMG),

air,

there

the

A known w e i g h t stirring,

volume

in

Accordingly, one of

CSG u s e d

and

in

packing

strand

important in

on

0

occur,

filamentised.

shear

based

1/φ ·

chopped

ratios

it

became

the

represents

measurement

dispersed The

spheres If

is

a RRIM

at

geometry.

to

head,

shape and s i z e

have been p u b l i s h e d by M i l e w s k i

However,

its on

Fraction

c o r r e s p o n d i n g to

σ

study

extending

mixing

in

rheology

and p l a t e

a t t a c h e d to

hammer-milled glass

direct

fibres,

influence

behaviour

This

cone

the

Packing

a defined (φ )

uniform

volume

Here

Fibre

of

in

viscometer

= 0.74.

0

glass

slurry

s~1.

viscometry,

conditions

fraction

packing,

by

r a n g e 0-10^

High

particles

of

and i t s

recirculation

and p o l y o l

with modified

Measurements

bulk

to

polyol

viscometry

capillary

For

dimensions

rheology.

A study,

lating

volume

packing behaviour

on f i b r e

-

1 .38

definite

+ 0.0376U/d) w

implications

1

for

,

(2)

4

the

maximum f i b r e

loadings


to

CROSS ET AL.

Rheology of Polyols and Polyol Slurries


O20i

015

0.10

0.051-

(Vd)n 50

100

150

F i g u r e 1. P a c k i n g f r a c t i o n (0 ) of g l a s s f i b r e s as a f u n c t i o n of number average J?/d. K e y : Ο, S o n o d i s p e r s e samples; X , bimodal samples. (The p o l y o l b l e n d used was PB021 ( Ο . 0 : 2 : 1 of p o l y o l s T 3 2 / 7 5 : LHT240: EG. The f i b r e s were CSG of 17 μπι diameter. Bimodal m i x t u r e s were o b t a i n e d by u s i n g p a i r s of monodisperse samples such t h a t the d i f f e r e n c e s between weight and number averages were as l a r g e as p o s s i b l e . )


100

REACTION INJECTION M O L D I N G

which £w

c a n be u s e d

=

1.5mm,

fraction 0.45mm


gives

in

polyol

give

l/d

= 30

fraction

of

0.339.

would a good

Modified

Cone

Preliminary

gap

cone

setting

both

higher

of

the

using

is

Difficulty sample

the

cone

relative

the

readings

operating

The

cone

fluid. the face

In

that

theoretical of

the

in

from

be a c h i e v e d ,

longer

were of

of

high

meet It of

cone

rate

of

basic

its

shear

test

cone

is

operate with

cone

apex

In

set

this

at

programs

have been w r i t t e n

has

been

the

The

test

cones.

associated this

system

With

Figure the

The 3

the

work

the

torque

reason

the

truncation

geometry,

of

cone the

cone

there

over

kept

the

small.

large is

gaps

no

Accordingly and

used

a new

involve are

to

is

ω.

such

be p u b

a function

of

Computer The

which

analysis

can be

re

angle. annular

a comparison of

developed is

does not

zero

to sur

viscosity/shear

analyse data.

concept

truncated

with

to

with

shows

there

measured torque

plate

test

set

the

difficult

velocity

plate

the

a displaced

sample.

present

angular

and used

and P l a t e .

be new.

the

and

way r e l a t i v e l y

regarding

fluid.

parallel

a d i s p l a c e d cone

annular for

a p p l i e d to

large

a displacement

disadvantage that

within

c and i t s

not

normally

to

Essentially,

displacement

of

the

modifications

contact with

mathematical analysis

elsewhere.

speeds

cone

possible

b a s i c assumptions the

rotate

balls

within

in

the

shear

the

of

is

plate. is

with

place,

low

Two

apex

the

because

to

take

advantage of

rate

the

Cone

and

adopted.

of

to

for

with

plate

w h i c h was

Details

Annular

pip

be a s s o c i a t e d w i t h

r h e o l o g i c a l d a t a becomes more

of

did

assumptions.

thought

and

The

resembling

and p l a t e ,

condition

also

the

the

relatively

clumps

seemed t o

The

where

there

at

into

a uniform

with

rotation

problem which

The

a

cone

impossible

the

as

using

using

gap c o r r e c t l y

to

garded

slurries

aspect ratio

suspended p a r t i c l e s .

this

is

i.e.

the often

Shearing

geometry were

to

involves

also

also

a central

movement o f

also

forming

the

provides

but

setting

and when

erratic.

position

a uniform

cone

to

and

mono-

encountered

approach

lished

2

for

cones.

mathematical

the

(2)

fibre

cone w i t h

fibres

was

plate,

and P l a t e .

surface

characteristics

It

it

computation of

normally

equation

and p a r t i c l e

vertical

difficulties

plate.

'c'

with

to

fibres

size

system,

the

weight

length

= 0.0173

0

rheogoniometer

difficulties

gap between the

the

can the

very

These

order

cone/plate

the

and p l a t e

is

that

a

fibre

φ

Milewski

on g l a s s

a truncated

Serious

position.

D i s p l a c e d Cone

geometry

the

and a F e r r a n t i - S h i r l e y

standard

experienced in

to

were

narrow the

in

resulted

wool.

geometry,

resistance

test

cotton

attempted

particularly

was

the

of

d a t a of

(e.g. to

concentrations.

high

compared w i t h

=100

w

same d i a m e t e r ) ,

may b e n o t e d the

U/d)

corresponding

Reducing

a Weissenberg

essentially

fibre

sometimes

It

both

purposes.

very

the

of

were

and p l a t e

instruments,

at

stream.

(for

instruments,

viscometer

particle

with

= 0.0398,

0

Viscometry

measurements

cone

a fibre

φ

rods.

and P l a t e

laboratory

truncated

the

representation

wooden

plate

Thus

0.092

disperse

two

RRIM.

gives

of

a weight

in

d = 0.015mm)

is

a small

flat In

cone

is

truncated

error

surface, turn,

and and

this


imposes

CROSS ET AL.



7.

Figure 3.

T r u n c a t e d and a n n u l a r

cones.


101

102 a

REACTION INJECTION MOLDING limit

to

normally With

attainable

the

the

range

of

the

radii

a]

and a2-

and the

ches The

unity

torque

the

τ

gap w i d t h , to

cone

is

there

σ is

the

=

shear

the

the

viscosity,

1 a

for

cone,

the

η,

The

conventional of

and the

difficulties

were

to

represent

using

adopted the

largely

a

non-Newtonian

for

wide

and w i t h of

flow

curves

in

for

PBA1478,

This

is

different

(see

to

be

subsequent

employed,

although

fibre

fibres.

slurries

concentration.

found

all

gaps

overcome,

longer

new

checked by c o m p a r i -

A g r e e m e n t was

were With

was

fibre

were

polyols

sition

and v i s c o s i t y , molar

and

mass

11.3

CO)

exhibited

slight increase

illustrated w/w

in a

in

Figure

concentrations

measured w i t h

Figure

5

At

the

a given

a plot

against

volume

lengths

suspended i n

the

relative

only

apply if Figure

slurry

viscosity,

dotted

vertical

different

fibre

5

in

both

viscosity

of

3°

the is

two

the

fibres the

and a l s o

the

indicate

lengths

are

major

and i t

is

was

no

the

of

CSG o f

should

Again there to

the

of

of

different

is

evidence

be emphasised t h a t of

fibre

packing

experimental seen t h a t ,

media.

rate

precise nature

a well-defined

influence

in

a

signifi-

two

slurries

influence the

of

zero

polyols.

in

there

other

respectively

at

insensitive

two compo-

b l e n d and the

viscosity

for

it

in

chemical

25°C b e i n g

viscosities

relative

However,

shows

lines

of

at

concentration

relative

concentration,

suspending medium.

sion.

viscosities

between the

shows

70um HMG d i s p e r s e d

significantly

one b e i n g a d i o l / t r i o l

triol,

Poise.

differences

measured using

differing

higher

will

angular

cone.

different

the

cone measurements

validity

became more marked w i t h

Viscosities

that

3°

and'fitted

glass

a series

fibre

aluminium

which

CSG d i s p e r s e d

shear

A prototype in

the

1.5mm,

1.4

made

behaviour,

4 with

cant

(3)

(4)

decalin.

slurries.

general,

length

annular

in

remained a problem with

fibre

. = σΑ

2

(5)

1100um was

new t e c h n i q u e s

on f i b r e

In

2. a )

total

= ω/α

c o n e / p l a t e geometry

experimental

thinning

by

-

of

configuration.

and the

given

,2

value approa

= ατ/(ωΑ)

polyisobutylene

shear

is

the

a-|/a2

and p l a t e

the

bounded by

by

and t h e i r

measurements

Results.

to

As

maintained

surface

and a n n u l a r

techniques

solution

clumping

limitation

a ring

is

since

surface

viscometer.

son w i t h

excellent,

no

cone/plate system.

d i s p l a c e d cone

expérimental

are

Also

given

a gap w i d t h o f

a Ferranti-Shirley

is

error

conical

2j 2πσ da = - y -

= ω/tana

is

conventional

with

Gap w i d t h s

2

stress.

η as

a.

comparable the

to

rate

conical r 3

2πσ

γ and

there

shear

a

where

no

over

approximates

over

τ

is

developed

uniform

developed

tan

can be c o m p a r a t i v e l y l a r g e .

system of

a2

100Mm.

Consequently

gap w i d t h

condition

torque

10

annular

whole a2,


the

in

state

of

disper-

aspect ratio behaviour.

values each

of

this

of

case,

φ

0

the


for

on

The the


CROSS ET AL.


F i g u r e 4. Flow curves f o r 1.5mm CSG d i s p e r s e d i n PBA1478. (1) f o r s p e c i f i c a t i o n of p o l y o l b l e n d PBA1478.


See




7.

viscosity approach The by

is

rising

to

a s y m p t o t i c a l l y as

conditions

viscosity

replotting

viscosity

at

n

zero

of

data

as

r


k

is

ised

called

derived

from

gives

volume f a c t o r

kφ

=

0

1,

shows

accordance

against

in

large

the

curves

of

7

and p l a t e

viscometers ,

2 χ

are

essential,

d e s i g n and c o n s t r u c t

attachment The

mixing

1/4 in

could of

head

of

employed

inch outer inner

be r a p i d l y

highest

extended to narrow

bore

an epoxy

fittings mounted

was at

The

linear

values

gradient

of

of

the

φ

0

linear

equates with

the

to

superposed and of

relative

linearised

fluidity

to

is

liquid

the

of but

in

with

rate

rate

5 χ

head.

tubing, lengths.

the

the

10-*

the

drop

minimise

these

a float

in

were

were used

to

for

measure in

where

to

entered

the of

centre the

in

tube.

collected

Liquid

6 horizontal

tube

Swagelok

diameter,

connected

in

range length

and hence

order

the at

inch

transducers

In

of

on

The

i.d.

inch

a l o n g the

any i r r e g u l a r i t i e s

through

inch

RRIM m a c h i n e ,

tube

1/4

s"^ .

1/4

c a p i l l a r y was

a vertical

use

selected

requirements

a 3/16

a p p r o x i m a t e l y 35cms

through

b a f f l e d by a d i v e r s i o n

were

pressure

pressure

for

was

cementing a short

inside psi

of

it

the

steel

available

was

displacement transducer. to

much

region

in

suitable

thickness

expedient of

0-5000

is

viscometer

c a p i l l a r y and n o r m a l l y

emerging from

cylinder order

to

diameters

was m e a s u r e d b y m e a n s o f

a linear

rate

a p p r o x i m a t e l y 500cm^ s ~ 1 .

cylindrical vessel,

collecting

is

the

Accordingly,

stainless

and cut

tubing

rate where

interchangeable capillaries

and w a l l

r e c o r d the

the

level

of

limit in

conditions

Compatability with

volume flow

viscometer,

shear

However,

the

retained.

mode

rates

shear

slurries,

practical

(o.d.)

shear

inch o.d.

end of

attainable

glass-fibre

shear

internal

rates

by

adhesive.

thus

usual

s~1

3/16

highest

a high

(i.d.)

attainable

large

was

the

and c o n v e n i e n t l y i n t e r c h a n g e d by the

this,

base

5

simulating

diameter

shear

1θ6

each

differential

ture

The

a RRIM m a c h i n e .

operating pressures.

the

liquid

relation and

CSG c a n b e

using

a plot

a series

diameter

attainable

high

the

(5)

(7)

the

estimated

i n c h Swagelok f i t t i n g s ,

using

for

viscosity

with

with

a RRIM m a c h i n e ,

viscometer

on

a

compares

for

differing

of

A

0

1

the

but

to

decided

was

-φ)

0

Figure

s"*',

the

tubing

φ/φ ·

viscosity.

data

reduces

1

in

the

curve

relative

RRIM V i s c o m e t e r

region of

s-1

basis

of

the

(6)

(φ

with

10

1/4

a single

that

°

the

6

σ

This

These

function

intrinsic

6

- [1-Φ/Φ ]"

Equation

gap d i m e n s i o n s

based

Μ >

to

gives

intrinsic

lower. 6

(6),

log

Equation

four

an

σ

cone

the

the with

with

d e r i v e d by Mooney

σ

against

r

i.e.

0

φ/φ .

High-Shear With

a unique

Equation

i.e.

n 6

is

and φ/φ »

dimensionless

and

φ ,

indicating

0

0

r

to

c a n be reduced

φ/φ >

sedimentation measurements.

plot

in

5

of

= [1-Φ/Φ Γ

with

log n

bulk

Figure

rate

r

the

conformity

by p l o t t i n g

Figure

and Dougherty

n

In

of

viscosity

m o d i f i e d , by K r i e g e r

φ tends

maximum p a c k i n g .

a function

shear

between d i s p e r s i o n

where

105


CROSS ET AL.

a

the

the

arma

the of

the

surface

it

channels arranged



106

radially of

at 60° angular

spacings

By

connecting the output

recorder, is

the rate

the radius

of

of rise

Also,

if

Newtonian

at the base

2

radius

flow,

is

If

Ρ is

the pressure η of

η The

capillary

the appropriate

d^

of

the tube d2

Viscous order was

heating

walls

is

perfectly are

is

=

3

r,

(8) the shear

2

along is

4

were

steel

tubing.

or more,

that

Correction.

and shear

t h e measurements

i n the c a p i l l a r y . both

andalso

adiabatic,

In it

fluid

viscosity

t o have been

first

the f i r s t

conditions

where

ρ and s are the density mean t e m p e r a t u r e

response

rise

were

throughput

(height)

recorded, is

on the plateau

the volume-time This

shows

similarity is

gradient

indicated

drop,

7.

where

Ρ is

which

Equation

a specific

11

measure

three

t h e volume recording

The pressure

pulse

calculations essentially

is

were constant

.

f o r Ρ andΤ

relation

plot

is

between

Conformity

on a polyol

a linear heat

of

of the

linearity.

the theoretical

gave

side

A typical

andv i s c o s i t y

shown b y measurements

capillaries,

Under given by

was r e c o r d e d b y means

rise.

i n Figure

region,

for adiabatic conditions

is

liquid.

For each v i s c o s i t y

corresponding with

result

(7).

on the output

the pressure

i n form,

P,

such as

This

the liquid

i n the form of the pulses

consistent

was a l s o

variables

heat of the

the liquid

10°C.

shown

usually

heat drop,

U l )

and the temperature

andvolume

rectangular

A basic

of

namely

approximately based

of

of

conditions

P/(ps)

and s p e c i f i c

a n d c o u l d b e up t o

pressure

rise

chrome 1-alumel t h e r m o c o u p l e

quantities

The

-

the total

dimensions.

through

case

where

by Jakobsen and Winer

t h e mean t e m p e r a t u r e ΔΤ

treated

on the pressure

and c a p i l l a r y

it

influenced by

conduction

situation,

of other

of the

as 1 0 ° s"^,

limiting

c a n b e shown t h a t

noted

these

heat

for the other

rate,

equation

length

diameter

internal

The problem has been

shear

different

and the

be greatly

f o r t h e s i t u a t i o n where

independent

Τ

a measured

as high

would

and i s

and

9

With v i s c o s i t i e s

rates

the c a p i l l a r y ,

found.

the

Z

equation

T h e mean o u t e r

a micrometer

along

and

length

measured by weighing

stainless

depends only

for

of

(10)

volume

capillary

wall,

(9)

by the P o i s e u i l l e

per unit

The

at the

2

negligible,

essentially

fast

rate

3

the capillary

given

conducting walls.

dissipation

appears

R

rate,

( 4 R / r ) dh/dt

andTemperature

10 P o i s e

mathematically, the

flow

given by

was m e a s u r e d w i t h

anticipated

viscous

andQ t h e volume

to a pen

and,if

calculated.

Heating

of

vessel

transducer

was o b t a i n e d ,

= r P/(8R Adh/dt)

diameters

of

diameter

drop

the f l u i d

π

(dh/dt)

dh/dt

ÏÏR

y = 4(}/

viscosity

liquid

the c o l l e c t i n g

the c a p i l l a r y

assuming

a

block

of the displacement

of

Q =


in a cylindrical

the vessel.

with

Ρ

this

b l e n d w i t h two

of ΔΤ against

of 0.45 c a l g " ^ ,

in

P.

resonable


CROSS ET AL.


107


7.

τ

1

1

1

1

1

0

5

10

15

20

r

TIME ( S E C O N D S )

F i g u r e 7. T y p i c a l RRIM v i s c o m e t e r t r a c e s f o r p r e s s u r e and volume throughout.


REACTION INJECTION MOLDING

108 agreement

with

conventional

an e x p e r i m e n t a l v a l u e

method based

on the

of

0.50

mixing

of

cal g"

liquids

o b t a i n e d by

1

at

a

different

temperatures. The

viscometer

employing

supplementing range

of

the

The


up

could

pressures the

in

high

shear

from a s e r i e s

at

a known r a t e

Ύ]

and T2.

of of

was

rate

be used

r a n g e 0-50

shear

viscometer

high

also

the

rate from

shear

10

to

2

viscosity

and at

lower

known

p r o c e d u r e was

this

10

input

for

It

ranges

involved,

the

showed a l i n e a r

temperature obtained

capillaries, shear

rates

viscometer two

reduced up

to

are

is

rate

a very

unexpected

this s""

10^

included for show

thinning.

a shear

there

in χ

2

In of

shows

way t o 1

data for

conditions

comparison.

the

At

the

RRIM v i s c o m e t e r

approximately 3 χ

sharp

rise

in

10^

boundary l a y e r

the

of

but

investigation

a

limited

dependence mean blend,

different

25°C.

Data

for

Ferranti-Shirley

apparent v i s c o s i t y .

further

at

shear

but

rates

show

behaviour

s~^,

the

a polyol

lower

this

over

and w i t h

a temperature

obtained with

temperatures

temperature that

r e a s o n a b l e agreement and b o t h

and r e q u i r e s

associated with

8

temperature

built

obtained

reducing data to

assumed t h a t ,

correspondended to Figure

different

instruments

shear to

+ T^)/!.

(Tj

under

By

were

each

and output

temperature. viscosity

by

operating

viscometer

reference

t h a t the measured v a l u e

way t h e

data points,

single and

rates

s~^.

6

the

adopoted was

shear

from a compressor.

data in

data obtained in

individual

A simple

at psi

is

beyond This is

the

evidence

of

maintained this

point

rise

is

thought

to

quite be

effects.

Acknowledgments Financial

support

by

the

Science

and E n g i n e e r i n g

We a l s o

thank

some o f

the

Turner

Imperial

polyols

Brothers

Polymer

Engineering

Research Council Chemical

Industries,

used and P i l k i n g t o n s

Asbestos

Ltd.,

is

for

Directorate gratefully

the

Organics Division

Fibre

supplies

of

acknowledge.

of

Glass glass

Division fibre.


for and


Figure 8. V i s c o s i t y (η) versus shear rate (γ) for PB521 at 25 °C. , RRIM viscometer; data corrected to 25 °C as described i n text. , cone and plate viscometer data. See (1^) for speci f i c a t i o n of polyol blend PB521.


η

s

I

I ?

Î

!

>

C/3

ΙΑ

ο


110


Literature Cited 1. Barksby, N.J.; Dunn, D.: Kaye, Α.; Stanford, J . L . . ; Stepto, R.F.T., preceding paper. 2. Milewski, J.V. Reinforced Plastics/Composites Institute Soc. Plastics Ind., Inc., Proc. 28th Annual Tech.Conf. 1973, Section 31, pp 1-8. 3. Isham, A.B., Reinforced Plastics/Composites Institute, Soc. Plastics Ind., Inc., Proc. 33rd Annual Tech. Conf. 1978, 14-A. 4. Tucker, C.L.; Suh, N.P. Polymer Engg. and Sci. 1980, 20, 887. 5. Mooney, M.J. J . Colloid Sci. 1951, 6, 162. 6. Krieger, I.M.; Dougherty, T.J. Trans.Soc.Rheol. 1959, 3, 137. 7. Jakobsen, J.; Winer, W.O. Trans.Amer.Soc.Mech.Eng., Series F, J. Lubrication Technol. 1975, 97, 472. RECEIVED

April

16, 1984


Rheology of Polyols and Polyol Slurries for Use in Reinforced RIM

Recommend Documents