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Conference Proceedings
FUNCTIONALIZED POLYOLEFINS THAT DELIVER ROOM TEMPERATURE
ADHESION TO POLYURETHANES
Maleic anhydride (MAH) modified polymers and
ethylene acrylic acid (EAA) copolymers are known to
adhere well to polar materials in high temperature
processes such as in multi-layer film and sheet extrusion.
However these materials have been found to exhibit
unacceptable adhesion to polar materials such as
polyurethane foams adhesives and coatings in room
temperature applications. Three new developmental
products are now available for sampling which can be coextruded
with either low density polyethylene (LDPE)
propylene-ethylene elastomers or ethylene-?-olefin
elastomers and provide a high functionality surface layer
that enables adhesion to urethanes at room temperature.
Each product exhibits 100% cohesive failure from a
polyurethane foam applied at room temperature. Examples
of applications where these type of films and sheets would
be useful are: transportation (head rests consoles seating
headliners flooring); building and construction; consumer
durables packaging and the like. This paper describes
typical process conditions film and sheet properties and
adhesion performance of the functionalized polyolefins
that can adhere to polyurethane at room temperature.
FUNCTIONALIZED POLYOLEFINS THAT DELIVER ROOM TEMPERATURE ADHESION TO POLYURETHANES
Maleic anhydride (MAH) modified polymers and ethylene acrylic acid (EAA) copolymers are known to adhere well to polar materials in high temperature processes such as in multi-layer film and sheet extrusion. However, these materials have been found to exhibit unacceptable adhesion to polar materials such as polyurethane foams, adhesives, and coatings in room temperature applications. Three new developmental products are now available for sampling which can be coextruded with either low density polyethylene (LDPE), propylene-ethylene elastomers, or ethylene-?ñ-olefin elastomers and provide a high functionality surface layer that enables adhesion to urethanes at room temperature. Each product exhibits 100% cohesive failure from a polyurethane foam applied at room temperature. Examples of applications where these type of films and sheets would be useful are: transportation (head rests, consoles, seating, headliners, flooring); building and construction; consumer durables, packaging and the like. This paper describes typical process conditions, film and sheet properties, and adhesion performance of the functionalized polyolefins that can adhere to polyurethane at room temperature.
FLAME RETARDANCY OF POLYCARBONATE-PDMS COPOLYMER COMPOSITIONS
Inherent Flame Retardancy (FR) of copolymer
compositions of Polycarbonate–Polydimethylsiloxane is
presented in this paper. Properties such as limiting oxygen
Index char yield surface enrichment characteristics along
with UL94 performance are analyzed. Comparison is
made with neat polycarbonate. Superior inherent FR
coupled with good low temperature impact heat hydroaging
characteristics and transparency distinguishes
copolymer compositions from neat polycarbonate thereby
making these compositions excellent candidates for
engineering thermoplastic applications including medical
and food contact applications.
FLAME RETARDANCY OF POLYCARBONATE-PDMS COPOLYMER COMPOSITIONS
Inherent Flame Retardancy (FR) of copolymer compositions of Polycarbonateƒ??Polydimethylsiloxane is presented in this paper. Properties such as limiting oxygen Index, char yield, surface enrichment characteristics along with UL94 performance are analyzed. Comparison is made with neat polycarbonate. Superior inherent FR coupled with good low temperature impact, heat, hydroaging characteristics, and transparency distinguishes copolymer compositions from neat polycarbonate, thereby making these compositions excellent candidates for engineering thermoplastic applications including medical and food contact applications.
ADVANCED PROCESS DESIGN IN HIGH VOLUME KNEADER REACTORS USING MULTIPLE FEED PORTS TO AVOID CRUST FORMING FOAMING AND LOW HEAT TRANSFER
Kneaders reactors are used for combined unitary processing in the polymer industry for devolatilization compounding or polymerization. Multiple feed ports are used in screw type reactors to allow adding multiple substrates into one product whereas one unitary operation has to get to a certain degree of completion before the next substrate can be added. We have found that even for identical substrates multiple feed ports can be advantageous to avoid specific working points where the product behavior is disadvantageous for efficient processing. Such processes require advanced design simulation tools to predict process behavior. We compare simulation results on pilot and the scale up.
ADVANCED PROCESS DESIGN IN HIGH VOLUME KNEADER REACTORS USING
MULTIPLE FEED PORTS TO AVOID CRUST FORMING, FOAMING AND LOW
HEAT TRANSFER
Kneaders reactors are used for combined unitary
processing in the polymer industry for devolatilization,
compounding or polymerization. Multiple feed ports
are used in screw type reactors to allow adding
multiple substrates into one product whereas one
unitary operation has to get to a certain degree of
completion before the next substrate can be added. We
have found that even for identical substrates multiple
feed ports can be advantageous to avoid specific
working points, where the product behavior is
disadvantageous for efficient processing. Such
processes require advanced design simulation tools to
predict process behavior. We compare simulation
results on pilot and the scale up.
HOW CAN POLYMER RHEOLOGY BE USEFUL TO GUIDE PROCESSING
This presentation discusses the latest developments in
the field of nonlinear rheology of entangled polymeric
liquids resulting from nearly two dozens of publications
from the Polymer Dynamics Interface and Rheology
Group at Akron. The essential findings are that a)
entangled liquids respond to sudden startup flow
elastically and undergo cohesive failure or yielding before
subsequent flow is possible b) the flow field beyond the
yield point is dictated by the characteristics of the yielding
process that can be strongly inhomogeneous c) entangled
liquids possess finite cohesion that can be overcome after
flow cessation by internal elastic restoring forces.
HOW CAN POLYMER RHEOLOGY BE USEFUL TO GUIDE PROCESSING
This presentation discusses the latest developments in the field of nonlinear rheology of entangled polymeric liquids, resulting from nearly two dozens of publications from the Polymer Dynamics, Interface and Rheology Group at Akron. The essential findings are that a) entangled liquids respond to sudden startup flow elastically and undergo cohesive failure or yielding before subsequent flow is possible, b) the flow field beyond the yield point is dictated by the characteristics of the yielding process that can be strongly inhomogeneous, c) entangled liquids possess finite cohesion that can be overcome after flow cessation by internal elastic restoring forces.
THE EFFECT OF POST DIE PROCESSING TIME ON ADHESION
IN COEXTRUSION BLOWN AND CAST FILM
Peel strength between layers in coextruded cast film is
found to increase with increasing post die process time.
The results suggest that adhesion is limited by the time and
temperature available for bonding after new interfacial area
is created during drawing. This contrasts with previous
work in blown film where increases in peel strength with
process time were attributed primarily to stress effects.
The results from both processes however were found to
collapse onto a single master curve by multiplying the peel
strength by the modulus of the tie resin and dividing the
process time by the relaxation time of the tie resin.
THE EFFECT OF POST DIE PROCESSING TIME ON ADHESION IN COEXTRUSION BLOWN AND CAST FILM
Peel strength between layers in coextruded cast film is found to increase with increasing post die process time.The results suggest that adhesion is limited by the time and temperature available for bonding after new interfacial area is created during drawing. This contrasts with previous work in blown film where increases in peel strength with process time were attributed primarily to stress effects.The results from both processes, however, were found to collapse onto a single master curve by multiplying the peel strength by the modulus of the tie resin and dividing the process time by the relaxation time of the tie resin.
RELATIONSHIP BETWEEN STRUCTURE AND RHEOLOGICAL
PROPERTIES IN POLYMER/LAYERED SILICATE
NANOCOMPOSITES
Poly[butylenes succinate-co-adipate] (PBSA)
layered silicate nanocomposite was prepared by
melt extrusion of PBSA and organically
modified montmorillonite (OMMT).
Nanocomposites were prepared at a single clay
loading. Before taking rheological
measurements the nanocomposites were
characterized by X-ray diffraction (XRD) and
transmission electron microscopy (TEM). Stress
growth experiments were performed for both
pure polymer and nanocomposite. Flow reversal
experiments were conducted for
nanocomposites at different predetermined rest
time after cessation of forward flow. The
orientation state of silicate layers were also
investigated by cooling down the sample in the
rheometer before and after the forward flow and
then by performing X-ray in the transmission
mode.
RELATIONSHIP BETWEEN STRUCTURE AND RHEOLOGICAL PROPERTIES IN POLYMER/LAYERED SILICATE NANOCOMPOSITES
Poly[butylenes succinate-co-adipate] (PBSA) layered silicate nanocomposite was prepared by melt extrusion of PBSA and organically modified montmorillonite (OMMT). Nanocomposites were prepared at a single clay loading. Before taking rheological measurements, the nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Stress growth experiments were performed for both pure polymer and nanocomposite. Flow reversal experiments were conducted for nanocomposites at different predetermined rest time after cessation of forward flow. The orientation state of silicate layers were also investigated by cooling down the sample in the rheometer before and after the forward flow and then by performing X-ray in the transmission mode.
POLYLACTIC ACID COMPOSITES BASED ON IONIC LIQUID MODIFIED
CATIONIC AND ANIONIC CLAYS
Hydrotalcite anionic clays were reacted with
phosphonium ionic liquids containing different
anions. Montmorillonite cationic clays were also
reacted with the residual cation of the ILs after
modification of the anionic clay. The clays were
analyzed by FTIR thermal analysis EDX and X-ray
diffraction in order to determine the extent and type
of intercalation of the IL anions/cations at the clay
interlayers. The modified cationic and anionic clays
and their mixtures were then melt compounded with
polylactic acid and their effects on the thermal and
mechanical properties of the resulting micro- and
nano-composites were investigated.
POLYLACTIC ACID COMPOSITES BASED ON IONIC LIQUID MODIFIED CATIONIC AND ANIONIC CLAYS
Hydrotalcite anionic clays were reacted with phosphonium ionic liquids containing different anions. Montmorillonite cationic clays were also reacted with the residual cation of the ILs after modification of the anionic clay. The clays were analyzed by FTIR, thermal analysis, EDX and X-ray diffraction in order to determine the extent and type of intercalation of the IL anions/cations at the clay interlayers. The modified cationic and anionic clays and their mixtures were then melt compounded with polylactic acid and their effects on the thermal and mechanical properties of the resulting micro- and nano-composites were investigated.
EFFECTS OF PROPERTY MODIFIERS ON THE DEGRADATION
CHARACTERISTICS OF POLYLACTIC ACID
The properties of polylactic acid (PLA) may be modified
by the addition of clays or the incorporation of ionic
liquids (IL). The effects of clays depend on degree of
polymer intercalation and the presence of clay
organomodifiers. Some ionic liquids act as plasticizers
and lubricants reducing glass transition temperature (Tg)
and melt viscosity the effects depending on the IL
structure and its polymer miscibility. This article
compares the effects of different cationic or anionic clays
and different ILs on the thermal hydrolytic and soil
degradation of PLA as measured by molecular weight
(MW) changes and relates to the structure of the additives
and their degree of dispersion/dissolution in the polymer
melt.
EFFECTS OF PROPERTY MODIFIERS ON THE DEGRADATION CHARACTERISTICS OF POLYLACTIC ACID
The properties of polylactic acid (PLA) may be modified by the addition of clays or the incorporation of ionic liquids (IL). The effects of clays depend on degree of polymer intercalation and the presence of clay organomodifiers. Some ionic liquids act as plasticizers and lubricants reducing glass transition temperature (Tg) and melt viscosity, the effects depending on the IL structure and its polymer miscibility. This article compares the effects of different cationic or anionic clays and different ILs on the thermal, hydrolytic and soil degradation of PLA as measured by molecular weight (MW) changes and relates to the structure of the additives and their degree of dispersion/dissolution in the polymer melt.
DEVELOPMENT OF AN AUTOMATED RUNNER-VALVE SYSTEM FOR THE FILLING BALANCE IN MULTI-CAVITY MOLDS
Since the runner-valve system (RVS) was proposed
by the authors for the filling balance in multi-cavity
molds its balancing capability has been proved in many
experiments. However it is not practical to adjust the
valve manually during the molding process. Therefore
authors developed an automated RVS. A motorized
actuator with a small installation area was designed and
built. An experimental mold with 4 cavities was machined
and the actuators were installed. In order to reliably
determine the resin-arrival-time in the automated RVS a
new method based on the sigmoid function approximation
was developed and optimum sampling range was obtained
in terms of a characteristic time. The data processing
program for the approximation was designed by the
LabVIEW. This work is ongoing project so that
experiment using the automated RVS is going to be done.
DEVELOPMENT OF AN AUTOMATED RUNNER-VALVE SYSTEM FOR THE FILLING BALANCE IN MULTI-CAVITY MOLDS
Since the runner-valve system (RVS) was proposed by the authors for the filling balance in multi-cavity molds, its balancing capability has been proved in many experiments. However, it is not practical to adjust the valve manually during the molding process. Therefore, authors developed an automated RVS. A motorized actuator with a small installation area was designed and built. An experimental mold with 4 cavities was machined and the actuators were installed. In order to reliably determine the resin-arrival-time in the automated RVS, a new method based on the sigmoid function approximation was developed, and optimum sampling range was obtained in terms of a characteristic time. The data processing program for the approximation was designed by the LabVIEW. This work is ongoing project so that experiment using the automated RVS is going to be done.
EFFECT OF POLYDIMETHYLSILOXANE ON COPOLYMER-POLYPROPYLENE FOAMS IN BATCH AND EXTRUSION PROCESSING
Both batch and continuous foaming processes were
employed to prepare plastic foams from polypropylene
(PP) / polydimethylsiloxane (PDMS) blends. The
blends were batch foamed at different saturation
pressures using carbon dioxide (CO2) as the blowing
agent. Ultimately the blend foams exhibited better cell
morphologies and higher cell densities in comparison to
those prepared from PP alone. The increased solubility
of CO2 in PDMS made it as a CO2 reservoir to induce
more nucleation. It was also noted that the addition of
PDMS to the PP matrix generated a bi-cellular structure
i.e. very small cells in the larger cell walls. In the case
of extrusion foaming the addition of PDMS had a
pronounced effect on both the expansion ratio and the
cell density. At 5% CO2 content the maximum
expansion ratio of the blend foams increased to as much
as twenty-five-fold whereas the maximum expansion
ratio of neat PP was below 10-fold with the same die.
EFFECT OF POLYDIMETHYLSILOXANE ON COPOLYMER-POLYPROPYLENE FOAMS IN
BATCH AND EXTRUSION PROCESSING
Both batch and continuous foaming processes were employed to prepare plastic foams from polypropylene (PP) / polydimethylsiloxane (PDMS) blends. The blends were batch foamed at different saturation pressures using carbon dioxide (CO2) as the blowing agent. Ultimately, the blend foams exhibited better cell morphologies and higher cell densities in comparison to those prepared from PP alone. The increased solubility of CO2 in PDMS made it as a CO2 reservoir to induce more nucleation. It was also noted that the addition of PDMS to the PP matrix generated a bi-cellular structure, i.e., very small cells in the larger cell walls. In the case of extrusion foaming, the addition of PDMS had a pronounced effect on both the expansion ratio and the cell density. At 5% CO2 content, the maximum expansion ratio of the blend foams increased to as much as twenty-five-fold whereas the maximum expansion ratio of neat PP was below 10-fold with the same die.
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