Note: Descriptions are shown in the official language in which they were submitted.
~2~
THERMOPLASTIC POLYMERS WITH
DISPERSED FLUOROCARBON ADDITIVES
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to
thermoplastic polymers modified with certain
fluorocarbon additives.
Description of the Prior Art
It has recently been proposed to modify
thermoplastic polymers by incorporating therein
various oils, gums, etc.
U.S. Patent No. 3,485,787 discloses that
certain block coplolymers may be extended by
incorporating mineral oil therein. U.S. Patent
3,830,767 teaches that bleeding of the extending oil
from the block copolymer may be prevented by
incorporating a petroleum hydrocarbon wax therein.
U.S. Patent No. 4,123,409 relates to block
~opolymers having thermoplastic terminal blocks and an
elastomeric intermediate block. The patent discloses
blending with the copolymer a high molecular weight
oil which is compatible with the elastomeric block
portion of the copolymer. Where the elastomeric
portion is a hydrocarbon, the oil employed is a
mineral oil. ~here the elastomeric block is a
polysiloxane, a silicone oil is blended therewith.
U.S. Patent No. 3,034,509 discloses the
addition of silicone oil to polyethylene for use as
surgical tubing.
U.S. Patent No. 4,386,179 discloses the
dispersion of a polysiloxane throughout an elastomeric
thermoplastic hydrocarbon block copolymer.
Japanese Patent No. 60104161 describes an
anti-friction composite material comprising a resin
and more than 1%, by weight, of a fluorocarbon oil
-- 2
which have been injected molded togather in a manner such
that the oil exudes onto the molded surfaces of the resin
due to poor compatibility of the oil with the resin and
differences in viscosity between the resin and oil to
produce an anti-friction surface.
There is continuing research leading to the
development of novel polymeric materials whose properties
are tailor2d by incorporating therein various additives.
It is an object of the present invention to
provide novel thermoplastic polymer compositions having
unique properties and which find utility in a wide
variety of applications.
It is a further object of the invention to
provide a novel method for preparing thermoplastic
polymer compositions having properties and
characteristics heretofore unattainable.
SUMMARY OF THE INVENTION
These and other objects are realized by the
present invention which provides a composition of matter
consisting essentially of a thermoplastic polymer and a
perfluorinated hydrocarbon-polyether additive formed by
melt-blending said thermoplastic polymer and from about
0.01~ to less than 1%, by weight, of said perfluorinated
hydrocarbon-polyether additive selected from the group
consisting of an oil, qum, grease and mixtures thereof,
said additive having a lower surface energy than that of
said polymer; said blending resulting in a substantially
homogenous admixture of said polymer and said additive;
said admixture, upon cooling, resulting in a solid
thermoplastic composition wherein the concentration of
said additive through a cross-section of said solid
thermoplastic composition is lower in the interior
thereof and highar at the surfaces thereof.
A further embodiment of the invention comprises
a method of forming a composition of matter formed by
melt-blending a thermoplastic polymer consisting of a
A
~ ~ . . ~
styreneolefin block copolymer and from about 0.01% to
less than 1%, by weight, of a fluorocarbon additive
selected from the group consis~ing of a fluorocarbon oil,
a fluorocarbon gum, a fluorocarbon grease and mixtures
thereof, said fluorocarbon additive having a lower
surface energy than that of said ~olymer; said melt-
blending resulting in a substantially homogenous
admixture consisting of said polymer and said
fluorocarbon additive; said admixture, upon cooling,
resulting in a solid composition wherein the
concentration of said fluorocarbon additive through a
cross-section of said solid composition is lower in the
interior thereof and higher at the surfaces thereof,
i.e., is a gradient through a cross section of the solid
composition from a lower value in the interior or bulk
thereof to a higher value at the surfaces thereof.
DE~AILED DESCRIPTION OF THE INVENTION
Although most non-fluorinated polymers are not
compatible with fluorocarbon oils and gums and are also
not readily blended therewith because of the high
specific gravity of the fluorocarbons, the present
invention is predicated on the discovery t~at
thermoplastic polymers when efficiently melt-blended with
less than 1%, by weight, of a fluorocarbon oil, gum or
mixture thereof such that the fluorocarbon additive is
homogenously distributed throughout the melt, yield, upon
cooling, solid compositions which, because of the
differences in thermodynamic compatibility and surface
energy between the fluorocarbon additive and the polymer,
have higher concentrations of the additive at the surface
than throughout the interior thereof.
-s
-- 4 --
In the phrase, "concentration of fluoro-
carbon additive is a gradient through a cross-sectiOn
from a lower value at the center thereof to a higher
value at the surfaces" the term "gradient" is not
intended to suggest that the concentration varies
uniformly from the center of the composition to the
surface. Although this may be the case with respect
to some combinations of polymer and additive, typi-
cally, a much higher concentration of the additive is
at the surfaces of the composition with a mùch smaller
amount in the interior or bulk of the polymer.
This higher concentration of fluorocarbon
additive at the surface of the polymer enables the
provision of a polymer composition having heretofore
unattainable properties. ~hus, using very low
concentrations of fluorocarbon additive below 1~,
relatively high concentrations are attainable at the
surface.
The high concentrations of fluorocarbon
additive at the surfaces provide compositions having
the advantages of fluorocarbon-like surface
properties, i.e., grea~er hydrophobicity, lower
surface energy, non-adherent surface characteristics,
more chemically inert, lower friction, smoother, etc.
~5 In addition, the presence of the ~luorocarbon additive
enhances molding operations since it reduces
"sticking" of the composition to the mold surfaces and
enhances mold release. Also, the additive will,
because of the lubricant properties thereof, permit
higher speed processing o extruded objects, i.e.,
films, fibers and other objects formed therefrom and
with smoother surfaces; with the added benefits of
shorter injection molding cycles and higher extrusion
rates.
For biological or biomedical applications
of the polymer compositions, the fluorocarbon surfaces
are especially advantageous since they exhibit
superior biocompatibility in contact with tissue
-- 5 --
surfaces, cells, physiological fluids and blood as
compared with most thermoplastic polymers.
The compositions of this invention are
therefore particularly advantageous for such applica-
tions as blood and fluid handling, medical tubing;vascular grafts, mammary implants, joint and tendon
prosthesesr ocular implants, and the li~e.
Fibers prepared from compositions of the
invention possess superior surface smoothness and
uniformity and handling properties for weaving as well
as different textures and "feel" because of the
surface properties imparted by the fluorocarbon
additives. In addition, the compositions and methods
of the invention are advantageous and more economical
in the manufacture of fibers since the high
concentration of fluorocarbon additive at the surfaces
of the fiber facilitates high-speed processing with
less damage to dies, shuttles and weaving equipment to
produce more uniform, smooth melt spun fibers.
For the most part, the basic bulk
mechanical, physical and chemical properties of the
thermoplastic polymer employed are retained or even
enhanced for the compositions of the present invention
but acquire the fluorocarbon surface properties of the
additive due to the above-noted gradient concentration
of the fluorocarbon additive through a cross-section
of the composition from a lower value in the bulk to a
higher value at the surface. This makes the
compositions of this invention also advantageous for
molds such as those used for optical and electronic
parts, i.e., contact lenses, and for electro-optical
or electromechanical devices which require low surface
energy and low friction surfaces, i.e., video tapes,
compact discs for audio or video recording,
electromechanical switches, and the like.
The lower concentrations of fluorocarbon
additive in the interior portion of the thermoplastic
can also advantageously modify the bulX mechanical,
physical and chemical properties of the polymer,
~ ~ 2 ~
however, particularly with respect to the classes of
thermoplastic polymers discussed hereinbelow.
A unigue advantage associated with the
compositions of the invention is that if cut into
plural sections, the fluorocarbon additive in the
interior will migrate to the new surfaces formed by
the cutting operation.
A wide variety of polymers may be
utilized in the practice of the invention. Preferred
among the suitable polymers are:
I. Polyolefins such as polyethylene,
polypropylene, etc., are advantageously and preferably
employed in the practice of the invention because
fluorocarbon surface properties are achieved at very
low overall fluorocarbon additive concentrations. For
example, using only 0.5 wt~ of a 450 centistoke vis-
cosity perfluoropolypropylene oxide fluorocarbon oil
in low density polyethylene, a surface composition of
21 atomic % fluorine is achieved as shown by XPS
analysis. This surface is characterized by an
increase in hydrophobicity twater contact angle
changed from 61 for polyethylene to 94 for the
fluorocarbon modified composition) and a decrease in
surface energy (from 40.6 dynes/cm for polyethylene to
28.1 dynes/cm for the fluorocarbon modified poly-
ethylene); indicative of the significantly altered
surface properties achieved using only 0.5 wt% of
fluorocarbon additive. An improvement in mechanical
properties, greater ductility, i5 also achieved using
the fluorocarbon additive. Tensile elongation changes
from 840~ for polyethylene to 1100~ with 0.1~
F-additive and 1500~ with 0.3~ F-additive. The energy
required for extrusion ttorque) is also substantially
reduced.
II. Olefin copolymers and block
copolymers such as ethylene-propylene, and styrene-
olefin block copolymers such as styrene-butadiene,
styrene-butadiene-styrene, and styrene-ethylene/
butylene-styrene and s~yrene graft copolymers such as
~2~ÇJ~
styrene-butadiene-acrylonitrile (ABS) are another
class of preferred polymers for the practice of the
invention. For example, the modification of a
styrene-ethylene/butylene-styrene block copolymer
results in greatly improved mechanical properties;
from 825 psi tensile strength for S-E/B-S to 1600 psi
with only 0.1 wt~ additive. ABS graft polymers (i.e.,
Cycolac~) are readily modified to improve surface
properties; 0.3 wt% F-additive yielding 5 atomic ~
surface fluorine and an increase in hydrophobicity to
96- contact angle from 73- with 0.8 wt% F additive.
III. Polyether and polyamide polymers
and block copolymers such as a polyether-polyamide are
a third class of preferred polymers for use in the
practice of the invention. Mechanical, surface, and
processing properties here too are improved by low
concentrations of F-additive. For example, improved
tensile strength and ductility as shown by an increase
in tensile strength from 4030 psi to 4850 psi and an
20 increase in ~ elongation from 1 110% to 1490% with 0.1
wt~ F-additive.
IV. Polyesters such as polyethylene
terephthalate ~PET), polybutylene terephthalate (PsT),
aromatic terephthalates and isophthates, and
polycarbonates and polyurethanes such as those with
aromatic or aliphatic isocyanate derived polymers with
polyether or polyester soft segments are also
significantly improved by low concentrations of
F-additive. For example, PBT exhibits improved
extrusion and molding properties as well as
fluorocarbon surface properties; i.e., 5.3 atomic
surface fluorine with 0.5~ additive. Bisphenol
polycarbonater with 0.5 wt~ F-additive, has improved
tensile strength (7410 to 7930 psi~, increased
hydrophobicity (contact angle from 78~ to 97-), and
exhibits 32 atomic ~ surface fluorine.
2 ~ 2 ~
-- 8 --
V. Other vinyl polymers also exhibit
enhanced properties and fluorocarbon surfaces using
the additives of this invention. Such polymers
include acrylic and methacrylic polymers, i.e.,
polymethylmethacrylate, pol~methylacrylate, poly-
butylmethacrylate, etc., and polyvinyl chloride, and
various aromatic vinyl polymers, i.e., polystyrene.
With 0.3 wt%, F-additive, polystyrene
molding and extrusion is enhanced and surface fluorine
of 10 atomic ~ is achieved.
It is preferred to employ fluorocarbon
additives having a surface energy substantially lower
than that of the polymer with which it is compounded
in order to ensure the high surface fluorine
concentration described above.
Suitable fluorocarbon oils, gums and
greases include fluorinated hydrocarbons and
fluorinated hydrocarbon-polyether oils, i,eO,
Aflunox~ and Krytox~ oils and greases, in~luding such
oils, gums and greases as perfluoropolyethylene-
oxide, perfluoropolypropylene oxide, polytetrafluoro-
ethylene oligomers, perfluoropolyethylene-propylene,
perfluoropolybutadiene oligomers, polyvinylidene
fluoride oligomers and their copolymers and perfluoro-
hydrocarbon oils such as perfluorocyclohexane,
perfluorohexane, perfluorodocedane and higher
molecular weight homologous linear or branched
perfluorohydrocarbons, and perfluorinated cyclic
hydrocarbons.
The preferred fluorocarbon oils, gums and
greases of this invention are characterized by having
viscosities in the range of 20 to more than 50,000
centistokes at 20~C, and the preferred fluorocarbon
greases useful in this invention are characterized by
having consistencies ~as determined by ASTM D-217) in
the range of ~LGI grades 0 to 6. Preferred greases
include those made by mixing or blending fluoro-
polyether oils with perfluorhydrocarbons, such as
~2Q'~a~
g
those prepared from mixtures of Rrytox~ fluoroether
oils with Vydax~ fluorotelomers.
The selection of a particular oil, gum or
grease will depend, of course, on the intended
applica~ions of the resultant composition.
Generally, it is preferred that the
fluorocarbon additive have a lower surface energy, by
more than about S dynes/cm, as compared with the
polymer with which it is compounded.
It is a particularly advantageous feature
of the present inven~ion that extremely small amounts
o~ fluorocarbon additive may be incorporated in the
thermoplastic polymer to achieve the hi~hly unusual
and desirable properties associated with the
compositions of the invention.
The method of the invention for
compounding the polymer and fluorocarbon additive
enables the use of such small amounts. ~y ensuring
that the melt-blending step results in a homogenous
admixture of the ingredients, one is able to obtain,
upon cooling the melt, a solid composition having the
above-described gradient concentration. If the
ingredients are not homogeneously melt-blended, the
product will comprise a composition wherein a sub-
stantial amount of unmixed free fluorocarbon additivesimply coats the surface o~ the polymer. Because of
the incompatibility of the ~-additive and the dif~er-
ence in ~urface energies between the polymers and the
fluorocarbon additive, the latter will not readily
dif~use into and penetrate the polymer to any appreci-
able extent. Relatively uniform dispersion of the
additive throughout the polymer during preparation
requires homogenous blending in the melted state.
This is not achievable by the mixing normally obtain-
able by injection molding or single screw extrusion.Attempts to mold or extrude thermoplastics blended
with as little as 0.5 wt~ or 0.25 wt% fluorocarbon
. L ~ ~
-- 10 --
oil additive in modern screw/ram injection molding
machines or single screw extruders result~ in
substantial melt inhomogeneity and screw slippage in
the melt with consequent erratic flow ma~ing it
impractical to form the polymer by simple molding or
extrusion without first using the efficient high shear
compounding blending method of the invention.
A melt-blending apparatus which ensures
homogenous mixing of the ingredients is required. It
has been found that a twin-screw compounding
blender/extruder is particularly advantageous and is
therefore preferred for carrying out the method of the
invention.
Any suitable temperature which is below
the decomposition temperature of either the polymer or
additive but above the sof~ening point of the polymer
and which ensures homogenous admixing of the
ingredients may be employed.
To facili~ate admixing of the fluorocarbon
additive with the polymer, it is preferred to employ
small particle sizes (e.g., pellets or powders) of the
polymer. This ensures efficient wetting of the
polymer particle surface prior to melt-blending
thereby ensuring efficient dispersion of the additive
throughout the polymer.
In the most preferred embodiment, the
fluorocarbon additive is pre-mixed with a fraction of
pelletized polymer and the thus wetted fraction or
pre-mix is then admixed with the remainder of the
polymer and subsequently melt-blended in an efficient
high shear compounding extruder such as a twin screw
compounding extruder-blender.
A major improvement in melt processing for
homogeneously blended compositions of this invention
is achieved by the incorporation of <1 wt% of the
~2~9~
~luor~carbon additive. In addi~i~n to smoother
surface finish and more uniform melt flow which is
critically important for forming precision parts,
fibers and films, less torque or pressure is required
for many compositions as compared to the normal
thermoplastic polymerO For example, a reduction in
extrusion torque ~rom 3700 meter-grams to 1950
meter-grams is achieved for low density polyethylene
containing only 0.5 wt~ fluorocarbon oil.
~he invention is illustrated by the
following non-limiting examples in which all
percentages are by weight except as otherwise
indicated.
EXAMPLE 1
This example illustrates the need for
highly efficient compounding blending for homogeneous
mixing to achieve the compositions of this invention
and the inability to obtain such good mixing of
the fl~orocarbon additives of this invention in
conventional screw-ram injection molding or normal
screw extruders which are not designed for high shear
compounding.
Pellets of an S-E/B-S thermoplastic
(styrene-olefin block copolymer, Shell Kraton G) were
added to the hopper of a screw-type injection molding
machine of the latest design and equipped with open
loop electronic controllers for controllng injection
speeds, pressures, speed changeover positions, screw
rotation speeds, metering, decompression, etc. A mold
for a 4.00 x 4.00 x 0.25 inch part was used and
conditions were set and tested to insure good molding
of the part with the base polymer. The base polymer
was then purged from the hopper and hopper screw.
Base polymer was tumble mixed with 0.5 wt%
2 ~ 2 ~ ~ ~L~
fluorocarbon oil (perfluoropolypropylene oxide,
viscosity 450 centistokes at 20-c) to insure uniform
coating of the pellets which were then carefully
introduced into the injection molding machine screw
for molding under conditions used for the base
polymer. It was found, however, that the polymer
containing 0.5 wt% additive would not feed adequately
for molding. Satisfactory molding could not be
achieved despite testing a number of variations in
screw speeds and other molding conditions. A similar
result, inability to properly feed and mold the base
polymer with additive was observ~d using only 0.25 wt~
additive. A major problem was the slippage of
material around the screw flights which resulted in a
tS pressure through the screw which was inadequate to
move the melt through the nozzle for satisfactory
injection molding. From this experiment, it is clear
that homogenous blending is essential for preparing
compounds which can be injection molded or extruded to
yield uniform parts. High shear compounding-blending~
such as that achieved in a twin-screw compounding
extruder of screw-flight design for efficient high
shear melt mixing, achieves such good blending for the
preparation of the compositions of this invention.
EXAMPLE 2
The following procedure was employed to
prepare the compositions identified herein.
A number of compositions were prepared
with dispersed perfluorocarbon oil (perfluoropoly-
propylene oxide, 450 centistoke viscosity at 20~C,
Dupont Krytox~ AX) in the following manner: The
appropriate weight of the oil was added to about 100
grams of polymer pellets as a premix. This was then ,
added to 1-2 pound quantities of the polymer which was
tumble mixed to uniformly distribute the premix
2~29D ~
- 13 -
pellets which had been wet wi~h the fluorocarbon oil.
In initial experiments, concentrations in the range
0.1 to 0.6~ oil were used and the polymer-pellet
premix appeared uniform. The oil-mixed pellets were
fed into an HBI System 90 microprocessor controlled
torque rheometer twin screw extruder (conical
twin-screw, three-quarter-inch compounding
blender/extruder, with a two-inch, heated strip-die
head~ to produce approximately 2-inch-wide film
extrusions of approximately 0.06-inch thickness.
Post-extrusion equipment involved chilling rolls in a
3-roll, take-up system. The extruder-rheometer
provided information during the compounding and
extrusion for torque, temperature, head pressure, etc.
The extrusion blending was generally run at speeds of
20-50 RPM.
The following polymers were blended with oil~
A. ~ow-Density Polyethylene (PE). Blends were
prepared using 0 1, 0.2, 0.3 and 0.5% oil. The virgin
resin was run first as a control before running the
blended compositions. The polyethylene blends
extruded well, exhibiting good oil compatibility with
no evidence of oil bleeding, even at 0.5~. Extrusion
temperatures were 440 to 460-F at 25 RPM. In addition
to the increased smoothness of the surface with
increasing fluorocarbon oil concentration, there was
progressive reduc~ion in torque from about 3700 meter
grams (M-g) for the unmodified polyethylene to about
1950 M-g for the 0.5~ blend. There was also a
reduction in the head pressure from about 720 psi to
about 525 psi. These are significant improvements in
extrusion processing conditions. The dispersion
homogeity of the fluorocarbon oil at concentrations as
high as even 0.5 wt~ was excellent using this method
of twin screw extrusion melt blending.
- 14 -
B. Polyproplyene (PP) was compounded with 0.1, 0.2
and 0.5 w~% oil. It, too, exhibi~ed excellent blend
homogeneity at all concentrations. Extrusion zone
conditions were 370 to 440-F at 25 RPM. FQr
polypropylene, there was a surprisingly rapid
reduction in torque from 4735 ~-9 for polypropylene to
1395 M-g with only 0.1~ fluorocarbon oil.
C. Styrene-Ethylene/~utylene-Styrene TPE Block
Copolymer (SEBS) was compounded with 0.1, 0.3, and
0.6% fluorocarbon oil and exhibited excellent blend
homogeneity at all concentrations. Extrusion was at
zone temperatures of 300-360-F at 45 RPM.
D. 50:50 81end of SEBS slock Copolymers (Shell
Rraton~ G2705 and G2706). This mixture was blended
with 0.1 and 0.6% oil at 2S RPM. The oil additive
even at the high concentration, exhibited good blend
homogeneity and smoothing of the surface with
increasing additive concentration.
E. Polyamide-Polyethy~ene Oxide BlocX Copolymer was
compounded with 0.1, 0.3, and 0.6% fluorocarbon oil at
35 RPM with zone temperatures set at 300-380F. The
torque for the unmodified material was approximately
2470 M-g and increased slightly to 3170 meter grams at
0.1~ additive and then dropped to 2200-2400 M-g at the
higher concentrations o~ 0.3 and 0.6%. A pronounced
smoothing of the extruded film surface was observed
due to the additive.
F. In another series of experiments on the same
twin-screw rheometer twin screw extruder, a polyester
tPBT), a polyurethane, an ABS resin, a polystyrene,
and a polycarbonate were each blended with various
concentrations of the fluorocarbon oil. In all cases,
in these experiments, surprisingly good blend
homogeneity of the fluorocarbon oil was observed with
visible improvements in extrusion and surface finish
of the resulting films.
9 L~ ¢~ ~
Samples were tested for tensile strength
and % elongation on an Instron, Model 1122 tester
using a 2-inch ASTM, die-cut dogbone sample.
Approximately five tests were run per sample at a
strain rate of 2 inches per minute. For some samples,
contact angle wettability using water and methylene
iodide was measured to determine the changes in
surface hydrophobicity and surface energy produced by
the additive. This was done with a Rami-Harte
goniometer using the method of Owens and Wendt.
Surfaces were analyzed for fluorine
concentration using XPS (X-Ray Photoelectron
Spectroscopy) on a Kratos spectrometer. Spectra were
obtained using MgK~ radiation at a pressure of
1 o-8 torr. with typical operating perimeters of
12KV and 20mA. Thiz technique samples the upper 50
angstroms of the surface for chemical composition,
The following analytical results were
obtained.
2 ~ 2 ~
- 16 -
POLYETHYLENE
-
A. Tensile Stren~th
(2 in. per minute/sample, thickness about 0.060 in.)
Sample ~ UTS Elongation
% F-additive (psi) (~)
_
1 - Nat. 3,930 840
19 - 0.1~ 3,870 1,100
2 - 0.2~ 4,070 ~,350
3 - 0.3% 4,170 1,500
154 - 0~5% 3,950 1,480
The ductility of the polyethylene is
enhanced significantly by low concentrations of the
fluorocarbon additive.
s. Surface Energy
_
Sample ~ Contact Angle ~ )¦ydisp. ypolar y Surf. energy
~ F- (water) (CH2C12) ¦
25 additive ¦ (dynes/cm~
1 - Nat. 61 66 ~16.5 24.1 40.6
19 - 0.1% 72 62 ¦20.8 13.6 34.4
2 - 0.2% 96 53 132.0 0.8 32.8
303 - 0.3% 95 57 129.0 1.3 30.3
4 - 0.5~ 94 61 ¦26.1 _ 2.0 2801
The surface energy decreases with increasing additive.
The polar component decreases significantly and a
smaller increase is noted in the dispersive component
resulting in a significant decrease in the total
surface energy, which is characteristic of a fluoro-
carbon surface.
a ~ ~
- 17 -
C. XPS Data
__
Sample # F
~ F-addit ive ( Atom . ~ )
2 - 0.2% 3.0
3 - 0.3% 12.2
4 - 0.5% 21.0
, _
The XPS results show much higher concentration of the
fluorocarbon additive at the ~urface as compared to
the overall amount added demonstrating ~he surpri-
ingly large effect of small fluorocarbon concentra-
tions in producing fluorocarbon surfaces. The
t5 FTIR/ATR spectra show the emergence of a new peak at
1240 cm-1 corresponding to -CF2-absorption, and its
intensity increases as the amount of additive is
inc~eased. The FTIR and XPS data correlate well.
POLYP~OPYLENE
A. Tensile Strength
Sample # UTS Elongation
~ F-additive(psi) (~)
5 - Nat. 4,310 730
6 - 0.1~ 4,280 770
7 - 0.3~ 4,200 700
8 - 0.6~ 4,32D 700
__
The mechanical properties did not change with
increasing additive concentration. The UTS was near
4,300 psi and the elongation was about 750% for all
samples.
- 18 -
STYRENE ETHYLENE/BUTYLENE STYRENE
A. Tensile Stren~
5 Sample ~ UTS Elongation
F-additive (psi) (%)
9 - Nat. 825 525
1010 - 0.1% 1,600 1r490
11 - 0.3% 1,600 1,410
12 - 0.6~ 1,680 1,510
The base polymer had poorer properties as compared to
the polymer with additive. Ultimate tensile strength
and elongation were surprisingly higher for the
samples with additive. The mechanical properties did
not appear to change significantly abovs the 0.1
level.
B. XPS Data
_
Sample ~ F
~ F-additive ~Atom. ~) _
11 - 0.3~ 1.7
12 - 0.6% 3.0
_ _
2 ~ x
POLYETHER-POLYAMIDE BLOCR COPOLYMER
A. Tensile Strenqth
Sample ~ UTS Elongation
5~ F-additive (psi) (~)
_
13 - Nat. 4,030 1,110
14 - 0.1~ 4,850 1,490
1015 - 0.3% 4,530 1,520
16 - 0.6~ 3,300 1,380
Additive levels of 0.1 and 0.3~ yielded hi~her UTS and
elongation.
MIXED SE~S ~LOCK COPOLYMERS
A. Tensile Stren~th
.
Sample ~ UTS Elongation
20% F-additive ~psi) (%)
17 - 0.1~ 1,370 1,670
18 - 0.6~ 1,270 1,549
~ ~ c~
- 20 -
EXAMPLE 3
The procedure of ~xample 1 was followed to
prepare and test the following compositions containing
0.1% to 0.8~ F-additive.
A. Polybutylene terephthalate tPBT) polyester
~hermoplasitc. glends were prepared With 0.1~ and
0.5% additive.
B. Acrylonitrile-butadiene-styrene (ABS).
thermoplastic. ~lends with 0.3~ and 0.8
additive were prepared.
C. Clear polystrene. Blend with 0.3~ additive.
D. Polyurethane elastomer with 0.5~ additive.
E. Polycarbonate with 0.5~ additive.
The results are set forth in the following
tables.
POLYBUTYLENE TEREPHTHALATE
Mechanical Testing-Tensile Strength and % Elongation
_
Sample ~ UTS Elongation
~ F-additive tpsi)
1 - Nat. 10,270 274
2 - 0.1% 10,110 203
3 - 0.5~ 10,330 274
2~2~ g~.
-- 21 --
Contact~le
Sample # Contact Angle (~
5% F-additive
1 - Nat. 57
2 - 0.~% 60
3 - 0.5% 71
1 0 - -- -
The water contact angle increa~e~
(increasingly hydrophobic) as the amount of additive
increases.
XPS Data
Sample ~ F
% F-additive (Atom. %)
1 - Nat.
2 - 0.1~ 3.5
3 - 0.5~ 5.3
_
ABS
Mechanical Testing-Tensile Strenth and ~ Elongation
30Sample # UTS Elongation
F~additive (psi) (%)
5 - Nat. 7,820 35
35 6 - 0.3~ 7,260 33
7 - 0.8~ 7,142 29
_
~ ~ 2 9 ~ ~ A~
- 22 -
Contact Angle
Sample # Contact Angle (-)
_% F-additive _ _ _ _
1 - Nat. 73
2 - 0.3~ 81
3 - 0.8% 96
1û
POLYSTYRENE
Contact Angle
_ ~
Sample # Contact Angle (-)
F-additive
1 - Nat. 72
~0 2 - 0.3% 80
_
XPS Data
_
Sample ~ F(%)
% F-additive
10 - 0.3% 10.0
2 0
- 23 -
POLYCARBONATE
Mechanical Testing-Tensile Strength and % Elon~ation
Sample # UTS Elongation
F-additive ~psi) (%)
17 - Nat. 7410 29
18 - 0.5~ 7930 3~
1 0 _ __
Contact Angle
_
Sample # Ccntact Angle (-)
% F-additive
17 - Nat. 78
18 - 0.5~ 97
- - -
XPS Data
-
Sample ~ F(%)
F-additive
18 - 0.5~ 32.0
