Note: Descriptions are shown in the official language in which they were submitted.
1269~L87
This invention relates to polymer resin composites
prepared by incorporating cellulosic fibers into a poly~eric
resin or resin blends.
More specifically the invention relates to such
enhanced polymeric composite performances and are derived
from readily available cheap materials.
Hitherto~ many kinds of thermoplastic composites
have been proposed and commercialized . The addltives used
thereln are lnorganic flllers such as calcium carbonate,
talc~ mica, asbestos, glass fibers, asphalt, silica
graphite, magnesium hydroxide, aluminium hydroxide and the
llke. However,these additives are Qf high cost and of high
specific gravities and their ablllty to improve physlcal
property of compositlon is not so sufficient. The other
known addltives used are ~he organic fillers such as starch,
flour, wood flour, wood pulp and the other cellulosic
flbers.
The published literatures include a number of
proposals, . which conslst essentially of thermoplastic
resinous matrix havlng dispersed therein cellulosic fillers
mlxed or not wlth lnorganic fillers. Such materials are
de~crlbed for example:-
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1269187
- U.S. pat. no 3,485,777 (1969), Gaylord, deals with
compatibilization of polyvinylchloride of polmethylmetha-
crylate with grafted cellulose.
- U.S. pat. no 3,645,939,also shows that polyethylene or
polyvinyl chloride or acrylic rubber can be compatibilized
with cellulosic fibers in presence of an ethylenically
unsaturated carboxylic acid or anhydride under conditions
which generate free radical on said polymer and cellulose.
- U.K. pat. appl. no. 2090849, Hishida,I., prepared
composites from thermoplastic resins by compatibilizing flax
fibers coated with a surface treating agent such as silanes,
titanates ..etc. in absence of a free radical initiator.
-U.S. pat. no. 4,554,215, Robbart, made composites coated
with alkylhalogeno-silane~also in absence of an initiator.
-U.S. Pat. no. 4,374,178, Kulkarni, prepared composites by
filling with calcium carbonate or sodium silicate and a
microcrystalline celluluse as a carrier by coating with
silane bonding agent.
-E.P. pat no. 0008143, Solvay & Cie and the Japanese pat.
no. 8011-537, showa, both teach the application of organic
and inorganic fillers in presence of a peroxide and an acid
anhydride, resulting composite materials having relatively
lZ691~
little improvements in their mechanical strengths.
-J 5 pat. no.7192-466, Showa,teaches the addition of an
unsaturated silane coupling agent onto the polyolefin matrix
by the effect of a catalytic peroxide and then by addlng
wood flour as a filler, but by silylating the matrix leads
to consuming more silane than in case of silylating the
filler itself. Furthermore the composites performances are
not highly improved.
-The applicant in his U.S. pat. no. 4,717,742, Beshay,
made composites by grafting the silane bonding agents onto
the cellulosic fibers by generating free radicals to
generate the interfacial strong bondings, from which the
composite perfomances are much improved.
- The U.K. pat. appl. no.2205569 , Beshay, realized more
improvements by mixing the silane grafted cellulosic fibers
free radically , with a silane treated inorganic fillers.
In summary~ we believe to be the first to prepare
composites of polymeric resin or resin blend and cellulosic
fibers, or starch, or flour, co-grafted with a small amount
of polymerizable functional monomer(s) or functional
oligomer(s) and with bonding agent(s). Those composites
characterized by having good physicomechanical properties,
and are easy to make from the available and cheap
components.
lZ691~7
The present invention is not only characterized by
enhancing the composite performances from the cheap
available fillers, but also characterized by its ability for
making composites having properties upon the different
required purposes. That may be realized by qualitative and
quar.titative variations of the compGsite constituents,
speci.ally for the gra~ting polymerizable functional
monomer(s) or functional oligomer(s) for the same
cellulose and for the same matrix.
SUMMARY OF THE INVENTION:
The cellulosic fibers ~ay well compatibilize with
polymeric or copolymeric resin or resin blends of
thermoplastic or thermosetting or rubber, by co-grafting
with polymerizable functional monomer(s), or functional
oligomer(s) and with bonding agent(s) together.
DETAILED DESCRIPTION OF THE INVENTION:
It has been found that the cellulosic fibers can
well compatibilize with the matrix of the thermoplastic
resin or resin blends and the strong covalent bonding
between the matrix and the fibers can substantially be
lZ69187
improved by improving the interfacial bonding of the
cellulosic fibers.
Co-grafting said cellulosic fibers with the
conventional polymerizable functional monomer(s) or
functional oligomer(s) and with the bonding agent(s)
together, confirms said interfacial strong bondings. The
preferred grafting processes are those carried out by
generating the free radicals.
The cellulosic fibers, starch, or flour may be:
a- Coated with both the polymerizable functional monomer(s)
or functional oligomers, and with the bonding agent(s);
b- Grafted with said polymerizable functional monomer(s), or
functional oligomer(s) and coated with the bonding
agent(s);
c- Grafted with the bonding agent(s) and coated with the
polymerizable functional monomer(s) or functional
oligomer(s); or
d- Grafted with both the polymerizable functional
monomer(s), or functional oligomer(s), and with the
bonding agent(s) together.
' ~Z691~7
Within the scope of the present inventlon and as
per non limiting examples, composites are made from wood
pulps or bagasse as examples for the other cellulosic
fibers. Acrylonitrile, styrene and methylmethacrylate are
as examples for the other polymerizable functional
monomer(s) or fumctional oligomer(s~. Silane A-174 and
A-llOO, (Union Carbide), and polymethylene polyphenylene
isocyanate (PMPPIC) are as examples for the other bor.ding
agents. Polyethylene, polystyrene and polyvinyl chloride
are as examples for the other polymeric or copolymeric
resins or resin blends of thermoplastic,thermosetting, or
rubber.
This inventionmay ~so include other additives for
more improvements, such as inorganic fillers and/ or
plasticizers, which may mix wit~l said polymeric or copol~meric matrix.
The inorganic filler(s) may mix with the cellulosic
fibers, starch , or flour befor, during, or after of any of
the coating and/o~ the grafting, or the co- grafting
step(s) as mentioned ab.ove. 8y means that the lnorganic
filler(s) may be coated or bonded with said polymerizables
and/or with said bonding agent(s).
This invention is not limited neither to the
materials, nor the substances used in the examples of the
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lZ691~7
present invention, nor to their weight pecentages, but it
shows its most usefull advantages for the following
materials to be used in any weight percent:
The cellulosic material to be used in the
invention includes saw dust, ground wood, wood pulps,
agricultural cellulosic fibers, cotton fibers or flakes,
flax fibers, rayon, bomboo fibers, bagasse, rice hulls, nut
shells, wood shavings, waste papers, cartons, cellulosic
cloth, also starch or flour, or the like.
The preferred cellulosic fibers for carrying out
the examples of the present invention are
chemicalthermomechenical wood pu].p derived from aspen and
semichemical pulp of bagasse.
The polymeric or copolymeric resins or resin
blends are those including polypropylene, polyvinylchloride,
polyethylene, polystyrene, polymethylmethacrylate,
polyacrylonitryl butadiene styrene (ABS) alloys,or other
polyblends, and may be those described in U.S. pat. no.
4,317,765, or other polymeric~ or copolymeric of
thermoplastic, or thermosetting resin, or resin blen~ or
rubber.
~Z~93L1 3~
- The preferred matrices in the examPles of the
invention are; linear low density polyethylene, polystyrene
and polyvinyl chloride and polymethylmethacrylate
The polymerizable functional monomer(s) or
functional oligomer(s) include the vinyl monomers or the
the monomers listed in the Polymer Hand Book, Interscience
pub., 1966, pp.VIII-2 to VIII-26 or their re~ated oligomers,
or the like.
The preferred vinyl monomers for carrying out the
examples of the invention are acrylonitrile, styrene, and
methylmethacrylate.
The bonding agents are silylating agents, titanium
coupling agents, zirconium coupling agents, isocyanates,
stearates,or the l1ke.
The silylating agents are comprising
gamma-aminopropyltriethoxysilane, gamma-methacryloxypropyl-
trimethoxysilane, propyltriethoxysilane, vinyltriethoxy-
silane,- vinyltri(2-methoxyethoxy)silane,
beta-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane gamma-
mercaptopropyltrimethoxysilane, gamma- aminopropyltriethoxy-
silane, n-beta-(aminoethyl), gamma-aminopropylmethoxysilane,
n-beta-(aminoethoxyl)-gamma-aminopropyltrimethoxysilane,
~Z69~ ~37
gamma- chloro-propyltrimethoxysilane or any other silylating
agents having the formula,
- Si - R
' 2
R3
r an oligomer ~hereof, wherein R , R and R are the same or
1 2 3
different and are selected from the group comprising alkoxy
with 1 to 6 carbon atoms, alkyl, alkenyl, cycloalkYl, with 1
to 6 carbon atoms, aryl, aralkyl, and organo-functional
radicals.
The silylating agents may be prehydrolized and\or,
diluted to form a monolayer onto the cellulosic fibers or
the fille(s) used, and to decrease the costs.
The titanium bonding agents are those as described
in the Modern Plastic Encyclopedia, 1986-87, pp. 128 & 130.
The isocyanates such as polymethylene
polyphenylisocyanate (PMPPIC), l, 6, and hexamethylene
di-isocyanate & NCO-(CH2 )6-NC0,2,4 toluene di-isocyanate or
their oligomers or the like.
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91~37
The preferred bonding agents to be used in the
examples of the inventiOn are
gamma-aminopropyltriethoxysllane (A-1100, Union Carbide),
gamma-methacryloxypropyl trimethoxysilane, (A-174,Union
Caxbide) and linear polymethylene
polyphenylisocyanate (PMPPIC).
Free radicals can be generated for the purpose of
forming interfacial strong bonding such as the covalent
bonds. The free radical initiator may be those from the
radiation sources or from the chemical sources. The radiation
sources such as gamma radiation, ultraviolet radiation ,laser
radiation, or the ultrasonic or the like. The chemical
initiation may be from any catalytic initiatorcausing the
free radical reactions, among which are the chemical
initiators listed in the Polymer Hand Book, Interscience
1966, pp.II-3 to II-51, or the like.
The preferred chemical initiators for carrying out
the examples of the invention are the chemicals used for the
known xanthation process for graft polymerization of vinyl
monomers onto cellulose, ceric ammonium sulfate,
sodium bisulfite, peroxides, or the like.
The ethylenically unsaturated carboxylic acid or
acid anhydride may be ~ded ~s~auxiliaries to be used in the
practice of the invention. such as maleic acid, maleic
1269~8~'
anhydride, fumaric acid, citraconic acid, or itaconic acid
or the like. Maleic anhydride is the preferred auxiliary
agent. Monocarboxylic acids such as acrylic acid or
methacrylic acid may also be used.
Instead of maleic anhydride , polymaleic anhydride,
succinic anhydride may also be used.
The inorganic fillers such as the hydroxyl
containing group, silica, calcium carbonate, kaolin, talc,
clay, mica, glass fibers, glass spheres, glass flakes,
wollastonite, carbon black, graphite fibers, metal fibers,
metal powders, metal hydrides, metal oxides partially
hydrated or not, metal compounds, diatomaceous earth,
silica, aramide, potassium titanate fibers, or the like,in-
either purified or unpurified form. Said inorganic fillers
are used as auxiliaries for obtaining more composite
improvements.
The preferred fillers used in the examples of the
invention are calcium carbonate, short glass fibers and
clay.
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i~:69~1~7
The p]asticizers which may be contained in the
matrix such as dipropylene glycol dibenzoa~e, dl-2-ethylhexyl
adipate, diisodecyl adlpate; azelates, di-2-ethylhexyl
azelate; phosphates, such as tricresyl phosphate, cresyl
diphenYl phosphate, 2-ethylhexyl diphenyl phosphate, di-n-
octyl phenyl phosphate, and tri-n-hexyl phosphat.e;
phthalates, such as diethylphthalate, butyl benzyl
phthalate, di-2-ethylhexylphthalate diisodecyl phthalate;
sebacates, such as di-2-ethylhexyl sebacate, and
terephthalates, such as di-2-ethylhexyl terephthalate;or the
like.
Other additives are optionally added, such as
colorants, antioxidants, lubricants, pigments, opacifiers,
heat stabilizers, impact modifiers, photostabilizers,
antistatic agents, biostabilizers, crystal nucleating agents,
or the like.
Concerning the weight percentages for the composite
constituants, accordindg to the present invention?may be
as follows:
The matrix resin or resin blend is....... from 1 to 98 wt.%,
(based on the total composite's weight.)
he celluloslc fibers, starch or flour is from 1 to 98 wt.%,
(based on the total composite's weight.)
The p~lymerizable functional monomer(s) or functional
oligomer(s).............................. from 0.5 to 300 wt%,
(based on the filler's weight.)
The bonding agent(s)................... from 0.001 to 20 wt.%,
(based on the filler's weight.)
The inorganic filler....................... from 0 to 95 wt.%,
(based on the filler's weight.)
The acid anhydride......................... from 0 to 10 wt.%,
(based on the filler's weight.)
The chemical initiator..................... from 0 to 10 wt.%,
(based on the filler's weight.)
The plasticizer............................ from o to 60 wt.%,
(based on the matrix' weight.)
The filler(s), whether from said organic or
inorganic nature may be in the form of powders, particles,
crystals, fibers, sheets, woven fibers, papers, cartons,
threads, cords, cloths~ gravels, chips, boards, panels
preshaped forms, or the like.
A composite material may be made according to the
invention by compounding from 1 to 98 wt% of cellulosic
fibers or starch or flour and from 1 to 98 wt. % of
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1269~7
polymeric or copolymeric thermoplastic or thermosetting
resin or resin ble~sor rubber, to bond wi~h each other by
coating and\or grafting, or co-grafting with both 0.5 to 300
wt. % of polymerizable functional monomer(s~ or functional
oligomer(s) and with 0.001 to 20 wt.~ of bonding agent(s).
The same composite material may additionally comprise from
0 to 10 wt.% catalytic initiator, from 0 to 10 wt. %
ethylenically unsaturated acid or acid anhydride. It may
also comprise from 0 to 95 wt.% inorganic filler(s) ar,d from
0 to 60 wt.% plasticizer(s). Said composite material is
optionally comprising colorant(s), antioxidant(s),
stabilizer(s), ~lame-retardent(s), lubricant(s), pigment(s),
opacifier(s), impact-modifier(s), photo-stabilizer(s)
antistatic agent(s), and crystal nucleating agent(s), or the
like.
The cellulosic fibers, or starch, or flour may be
grafted first with said polymerizable functional monomer(s)
or functional oligomer(s) by a known free radical process
or by any graft polymerization process leading to form
interfacial strong bonding such as covalent bonding.
The bonding agents may coat the cellulosic fibers
or starch or flour; or may graft by free radical grafting
process via the effect of any initiating source as mentioned
before.
~2~
The graftlng of said ~oth polymerlzabl monomer(s) or
oligcmer(s) and said bonding agent(s) onto said fillers
may be carried out simultaneously or successiveiy. The
simultaneous grafting is recommended for the industrial
economy.
The inorganic filler may be mixed wi~ the cellulosic
fibers, starch or flour, befor the addition step(s) of said
polymerizable(s) and said surface bonding agent(s). Said
mixing may also be after or during said addition.
The inorganic filler(s) may also be bonded or
coated with the said polymerizabl(s) and /or with said
bonding agent(s), befor or after the mixing step.
The experimentation results in the examples of the
invention could be improved or be reached their optimum
values by changing the preparation conditions, and/ or the
weight percentages of the applied materials or the
substances.
This invention will now be furtherly describ~dby
non limiting examples:
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lZ~
GROUP A :
10 g. of dried chemicalthermOmechenical wood pulp
derlved from aspen, ground at mesh 60 and wetted with
vapor of acrylonitrile, styrene~ or methylmethacrylate
monomer and silane A-174 or A-1100, or mixed with linear
polymethylene polyphenylisocyanate (PMPPIC), ~ or may be
dlssolved in a solvent sich as acetone, then sub~ected to a
method for pol~merising said monomers onto the surface of
said pulP fibers). This ls to obtain a traated or coated
aspen pulp with poly acrylonitrlle- silane A-1100, - silane
A -174; poly acrylonltrile - (PMPPIC);pol~styrene -silane
A-1100, -silane A-174, and polystyrene - (PMPPIC) or
polymethylmethacrylate- silane A-1100 or -silane A-174; an~
polymethylmethacrylate -(PMPPIC).
Mlxing 10, 20, 30 & 40 wt.% (based on the total composite
wt.) of these coated pulps, (by using a roll mill or a
compounding extuder) with 90, ~0, 70 & 60 wt.% of (hot
molten) linear low den~ity polyethylene, or polystyrene, or
polyvinylchloride, (plagt1cizer(s) could be added such as ln
case o~ P.V.C.) . Molding the resulted composites to shape
specim~ns for testin~ ënergy (k~ tress (mpa) and modulus
(mpa) according to ASTM, D1822-78.
The examples accordin~ to the group A are as follows:
X - 17 -
37
Example l;
The aspen pulp coated or treated with polyacrylonitrile &
silane A-llO0 and then compounded with LLDPE or pl~icized
P.V.C. resins.
Example 2;
The aspen pulp coated or treated with polyacrylonitrile
& silane A-174 and then compounded with LLDPE resin.
Example 3;
The aspen pulp coated or treated with polyacrylonitrile
(PMPPIC) and then compounded with P.S. resin.
Example 4;
The aspen pulp coated or treated with
polymethylmethacrylate & silane A-llO0 and then compounded
with P.S. resin.
Example 5;
The aspen pulp coated or treated with polystyrene &
silane A-llO0 and then compounded with P.S. resin.
The testing values are showing improvments with no
more than 60% based on their related neat resins.
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- GROUP B:
Following here the same experimentaion as per
group A, but the difference is by pregrafting the aspen pulp
first with 20 wt.% ( based on the pulp weight) of
acrylonitrile, styrene or methylmethacrylate by following
any of the known graft polymerization processes such as the
xanthation process. Then 10 g. of the prepared pregrafted
a~pen pulp is wetted with a vapor of ( an organic solvent
may be added), 0.2 g. silane-llO0, sllane-174 or mixed with
0.5 g. of PMPPIC, ( the silanes may be prehydrolized or
diluted, by evapora~ing the solvent, if present) to glve
aspen pulp grafted with polyacrylonitrile, polystyrene, or
polymethylmethacrylate, and coated with silane A-llO0,
sllane A-174, or PMPPIC; then compounding-the said resulted
grafted and coated aspen pulp with the polymeric resins
givlng the follwing examples:
Example 6 :
10, 20, 30, & 40 wt.% of Aspen pulp grafted with
polyacrylonltrlle and coated wlth sllane A-llO0, and
compounded wlth 90, 80, 70 & 60 wt.% of LLDPE, or
P.V.C. (plastlclzed) resins.
Exam~le 7 :
10, 20, 30, & 40 wt.% of aspen pulp grafted with
polyacrylonitrile ard coated with PMPPIC, then compounded
X - 19 _
with 90, 80, 70 & 60 wt.% of P.S. resin.
Example 8 :
10, 20, 30 & 40 wt.% of aspen pulp grafted with
polymethylmethacrylate and coated with silane A-1100, then
compound with P.S. resin.
The testing values are showing improvements from 70
to 760% based on their related neat resin.
Group C :
'rhe experimentation as per group A,but here it is preferred
to use an organic solvent which additionally co~prises ~.1 g.
benzoyl peroxide, then by subjecting to hot air current
till dryness, and by mixing with the polymeric resin to
give the follwing examples.
Example 9 :
10, 20, 30 & 40 wt.% of the co-grafted aspen pulp with
acrylonitrile and silane A-llOO,compound with 90, 80, 70 &
60 wt.% of LLDPE, or P.S. resins.
~xample 10 :
10, 20, 30 & 40 wt.% of the co-grafted aspen pulp with
polystyrene and silane A-llOO~compound with 90, 80, 70 & 60
wt.% of P.S. resin.
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lZ6gl~7
Example 11 :
10, 20, 30 & 40 wt.% of the co-grafted aspen pulp with
polyacrylonitrile and PMPPIC compound wlth 90, 80, 70 & 60
wt.% of P.S. resin.
The testing values for these examples showing
improvements from 85 to 1000 %, based on their related neat
resin.
Group D :
The experimentation here as per group C, but by
mixing the filler with 10 of its wt.% of calcium
carbonate, after the drying step to give the following
examples:
Example 12 :
10, 20, 30 ~ 40 wt.% of aspen pulp co-grafted with
polyacrylonitrile and silane A-llOO~and mixed with calcium
carbonate, compoundi with 90, 80, 70 & 60 wt.% of LL3PE or
P.S. resins.
Example 13 :
10, 20, 30 & 40 wt.% of aspen pulp co-grafted with
polystyrene and silane A-llOO,mixed with calcium carbonate,
compound with 90, 80, 70 & 60 wt.% of P.S. resin.
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~`- lZ~
The testing values show improvements from 90 to
1050 wt.% based on their related neat resins.
Group E :
As per group D but the calcium carbonate is mixed with the
aspen pulp befor the wetting step(s) to give the following
examples no. 14 & 15:
Eaxample 14 :
Using the filler of group E and the same composition as per
example no. 12.
Example 15 :
Using the filler of group E and the same composition as per
example no. 13.
The testing values are showing improvements from
100 to 1100% based on their related resins.
Group F :
As per group B for the pregrafting step of aspen
p~lp with acrylonirile, styrene and methylmethacrylate. Then
10 g. of the pregrafted aspen pulp is wetted with a vapor of
an organic solution comprising, 0.2 g. silane A-1100, or
0,5 g o~ ~ PMPPIC and 0.1 g. of benzoyl peroxide, then
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by passing a current of hot air and heatlng for a certaln
time and compoundins the given co-grafted aspen pulp with
polymeric resins to give the following examples:
Example 16 :
10, 20, 30 ~ 40 wt.% of the prepared co-grafted aspen pulp
wlth polyacrylonitrile & sialne A-llO0, are compounded with
90, 80, 70 & 60 wt.% of LLDPE or P.S. resins.
Example 17 :
10, 20, 30 ~ 40 wt.~ of the prepared co-grafted aspen pulp
wlth polystyrene & PMPPIC are compounded with 90, 80, 70 &
60 wt.% of P.s. resin.
The testing values are showing improvemnts from 100
to 1100~ based on their related neat resin.
Group G :
As per group F, but by mixing the co-grafted aspen
pulp with 10 wt.% ( based on the filler wt.) of short
glass fibers pretreated with silane A-llO0 (as delivered),
then compounding wlth polymeric resins giving the following
examples:
Example 18 :
10, 20, 30 & 40 wt.% of the prepared filler of group G,
wherein the aspen pulp co-grafted with polyacrylonitrile &
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`- lZS9187
silane A-1100, to be compounded with 90, 80, 70 & 60 wt.% of
LLDPE or P.S. resins.
Example 19 :
10, 20, 30 & 40 wt.% of the flller prepare.d as group G,
wherein the aspen pulp co-grafted with polystyrene & silane
A-1100 to be compounded with 90, 80, 70 ~ 60 wt.% of P.S.
resin.
The results are showing more improvement~ whic~
reached from 150 to 1200 %.
Group H ~ Example 20 :
g. of semichemical pulp of bagasse ground at mesh 60,
mixed with 10 g. of clay and-sub~ e~ted to gFa~t polymorization
with methylmethacrylate by the known sodium bisulfite
initiation method. After dryness, the filler is rewetted
wlth a vapor of 0.8 g. cf silane A-1100 in acetone solution
comprising 0.4 g. of benzoyl peroxide. Hot air current
passed for a certain time. Then 10, 20, 30 & 40 wt.% of the
resulted filler is well compounded with 90, 80, 70 & 60 wt.%
of powdered polymethylmethacrylate by using compressionr
molding processes.
The testing results give improvements from 90
to 1200 % based on the neat polymethylmethacrylate resin.
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