CA2045389A1 - Polymer composites based cellulose - viii - Google Patents

Abstract

ABSTRACT

This invention relates to polymer composites. More specifi-cally, it relates to the viscous resinous materials such as Asphalt and modified Asphalt. Furtherly, it relates to the use of the natural organic polymers such as cellulosic and lignocellulosic materials as a filler material for asphalt and/or as a reinforcing material

Description

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BACKGROUND OF THE I NVENT I ON

I. Field of the In~rentio~:
This invention relates to E~olymer composites. More specifi-cally, it relates to the viscous resinous materials such as Asphalt and modified Asphalt. Furtherly, it relates to the use of the natural organic polymers such as cellulosic and lignocellulosic materials as a filler material for asphalt and/or as a reinforcing material.

The term Asphalt in the current invention i9 meant for Petroleum Asphalt, Bitumen, Pitch, trinided Pitch, mineral Pitch, Tar, Asphaltic Bitumen, or bituminous Asphalt, Gilsonite, modified Asphalt, Asphalt bonding agent, polymeric Asphalt, Rubber Asphalt, Asphalt addetives. Aasphalt pai~t, Asphalt natural, fluxoil, or the like.

2. Description oi_Prior Art:
Many published literatures and awarded patents comprise a number o~ proposal~ which consist essentially of treatment of either the cellulosic fibers or the a~phaltic materials.

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For Example:
The use of cellulosic fibers in the field of polymers, whether thermosets or thermoplastics, is successfully used as a filler and/or as a reinforcing material for said polymers.

Beshay's US Pats. Nos. 4,717,742 ~ 4,820,749 and CA 1,252,586 are dealing with the reinforcement of thermoplastics, thermosets or rubber with cellulosic fibers gra~ted with a silylating agent, in presence or absence of an inorganic filler material.

The US Pat. 5,008,310, of the same inventor, is dealing with the grafting of cellulosic fibers in presence or absence of inorganic fillers by grafting with isocyanates bonding agents.

The CA Pat. 1,269,187 of Beqhay, is also dealing with the reinforcement of said polymers with wood fibers co-grafted with polymerizable monomers and with a bonding agent for ful~illing more improvements.

The US Pat. 3,861,933 (Japanese Pat. 7,224,145) ~ US Pat.
4,618,665 are teaching the improvement of the adhesion strength by using polysiloxanes.

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The US Pat. 4,036,561 teaches the use of aminoalkylpolyal-koxysilanes for improving the properties of Asphaltic material aggregates compositions.

The Asphalt was chemically modified for the mineral aggregates ccmpositions as per the US Pats. 4,170,484 and 4,173,489.

Silane~coated glass fibers have been used for Asphalt compositions as per the US Pats. 4,243,426, 4,292,371 and 4,34~,388.

Also US Pat. 4,2~5,485 is dealing with glass fibers compri~-ing phenolformaldehyde-urea resole, a starch, a dimer acid, an emulsified oil, and a copolymer of ethylene and vinyl chlo-ride or acetate, roofing.

In summary, we believe to be the first to prepare Asphaltic polymer composites of either by compounding the asphalt with cellulosic or lignocellulosic fibers, whether treated or not, impregnated or ~rafted or co-grafted with a bonding agent and/or with a polymeri2able functional monomer or functional oligomer.

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SU~Na~ QE~ INVENTION:

The asphaltic material i5 well compatibilzed with cellulosic fibers as such, pre~impregnated or grafted with a bonding agent and/or with a polymerizable functional monomer or functional oligomer thereof, in presence or absence of other aggregates and/or fibers.

DETAILED I~ESCRIPTION OF T E INV13NTION:

The use of cellulosic fibers to be as a filler and/or as a reinforcing material for Asphalt Cement or Asphalt Concrete, as per the current invention, has its characteristic advantages concerning the low costs, low density, high strength, high durability, shrink stability (even at low temperature degrees), and elasticity, ability for many ch~mical variations for the purposes of creating strong interfacial bondings. In addition to their abundant renewable nature as ~ell as the various applications from their wa~te~.

One embodiement of this invention is to use said cellulosic or lignocelluloqic fiber~, either pre-coated, pre-impregnated and/or pre-grafted or co-grafted with a polymeri3able functional monomer or oligomer and/or with a bonding agent or with any other chemical surface treating agents. Said celluloqic fibers cnuld be s . , .

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The cellulosic or the lignocellulo5ic fibers may also be used as separate fibers, in dif~rent lengths of fibers, or in different forms or shapes, such as wood fibers, cellulosic threads, cords, textiles or fabrics, cartons, paper(s), wood boards, wood pannels, wood sheets, wood chips, wood construction, shaped wood articles or the like.

A second embodiement of the current invention i5 said cellulosic fibers, whether treated or not, with said chemical treating agents, whether mixed or not mixed with inorganic filler materials, befor, during or after said chemical treating agents, can be mixed with the Asphalt resin directly to improve its physico-mechanical properties.

~ s a third embodiement of the current invention, said cellulosic filler materials can be mixed with the concrete or the aggregates to increase their adhesion strength with both the aggre-gates and the asphalt, in addition to the improvements in the physicomechanical properties of the resultant compGsites.

The chemical treatments of cellulosic fibers, whether by coatings, impregnation, grafting or co-grafting by bonding agents, : . , , ~ ~ - . . :

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or binding agents, or polymerizable functional monomers, or functional oligomers or any chemical surface treating agents, are not new in the Art. But, the current invention is for compatibili-zing said cellulosic materials with said Asphaltic materials and/or Asphalt cement, Asphalt Concrete or Asphalt aggregates to improve their physico-mechanical propert:ies, specially to be applied for paving roads and sealing water works, and/or other asphaltic applications, as water-repellents, heat resistance enamels, canals and reservoir linings, dam facings and other harbour and sea-works against weat.her and mechanical damages, thicker surfaces, roofs, coatings, floor tilings, sand proofing, water proofing, and other building construction elements, asphalt tiles as well as a great number of industrial products such as batteries.

The asphaltic material could be as such or in emulsion or in suspended forms.

The cellulosic or lignocellulosic fiber~ may compatibilze with an asphaltic material and the strong covalent bonding between the asphalt and the fibers. Accordingly, the physico-mechanical properties can substantially be improved by improving the surface treating agents onto the cellulosic ~ibers.

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The cellulosic fibers may be:
1. Coated with a bonding agent;
2. Grafted with a bondlng agent;

3. Impregnated with a polymerizable functional monomer or functional oligomer;

4. Grafted with said polymerizable functional monomer or funtional oligomer;

5. Coated with both polymerizabl~ functional monomer sr functional oligomer, and with a bonding agent;

6. Grafted ~ith said polymerizable functional monomer, or functional oligomer and coated with said bondin~ agent;

7. Grafted with a bonding agent and coated with the polymerizable functional monomer or functional oligomer; or 8. Co-grafted with both the polymerizable functional monomer, or functional oligomer together with a bonding a~ent what-soever which is f.irst.

Within the ~cope of the present invention and as per non-limiting e~amples, Asphalt composites are made from wood pulp and saw dust as e~ample for the other wood cellulosic or lignocel-lulosic fibers to be impregnated or grafted with styrene as an example for the other polymerizable functional monomer or func-tional oligomer and/or with Silane A-llOO (Union Carbide), poly methylene polyphenylene isocyanate (PMPPIC) which are as an ex-., , ~ , ~- - .
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amples for the oth~r said bonding agents. Bitumen 85/100 is as an example for other sorts of Asphalt.

This invention may also include other additives for more improvements, such as inorganic fillers or other polymeric fibers which may mix with said cellulosic or lignocellulosic fibers before, during or after any of the coating and/or the grafting step(s) as metnioned above. By means that the inorganic fillers or the other polymeric fibers may simultaneously be coated or bonded with saidi polymeriza~les and/or ~ith said bonding agents.

This invention is not limited either to the materials, or to the substances used in the examples of the instant invention, or to their weight percentages, but it shows lts most useful ad-~antages for the following materials to be used by any weight percentage.

The cellulosic material to be used in the current invention comprise saw dust, ground wood, wood pulp5, agrictural cellulosic fibers, cotton fibers or flakes, flax fibers, ra~on, bamboo fibers, bagasse, rice-hulls, nut shells, wood shaving, 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 chemicalthermomechanical wood pulp derived from aspen and wood saw dust.

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Th~ ~21~cted ~pha~tic material is Asphalt Cement, as an example o~ the other Asphaltic material5 guch as 3itumen, Pitch, Tar, Asphaltic ~it~men, Gilsonite, bitumeneou5 A~halt, modi~ied Asphalt, Asphalt bonding agent, Asphalt ~dditiJe, polymer Asphalt, rubber Asphalt, or the lik~.

Th~ polymerizable functional monomers or functional oligom~rs include the vinyl monomers or the monotners li.~t~d in th~ Polymer Hand Book, Interscience pub., 1966, pp. VIII-2 to VIII-26 or their related oligomers, or the like.

The prererred vinyl monom~r for carryin~ out the example of the invention is styrene.

Th~ preferred bonding agent~ that can be ~mploy~d in th~
instant invention, e.g. tho e from organic or organo-m~tallic nature such a.~ the ~ilylating agents, silo~ane bonding agent~, ti~anate~ coupling agent~, zirconate~ coupling agents, aluminate~
bondin~ a~en~i, stearate~, maleatei abietic a~id, linoleic acid or the like.

The silylating agents are comprising gamma-aminopropyltri-ethoxysilan~, gamma-methacryloxypropyltrime~ho~y~ilane, propyl-triethoxysilane, vinyltrietho~ysilane, vinyltri(2-methoxyetho~y)-~ilane, beta-(3,4-epoxycyclohexyl)-ethyltrimethoxy~ilane, gamma-mercaptopropyltrimethoxysilane~ gamma-aminopropyltrietho~Ysilane, n-be~a-~aminoethyl), gamma~aminopropylmethoxy~ilane, n-beta-(aminoetho~yl)-ga~ma-aminopropylt~i~ethoxy~ ano~ gamma-chloro-propyltrimetho~ysilane or any oth~r silylating ago~t(s) havi~g tho formula:

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or an oligomer thereof, wherein R , R and R are the same or different and are selected from the group comprising alkoxy with 1 to 6 carbon atoms, alkyl, alkenyl, cycloalkyl, with 1 to 6 carbon atom~, aryl, aralkyl, and organo-functional radical~.

The silylating agents may be prehydrolized ant/or dilut~d to form a monolayer onto the cellulosic fib~r~ or th~ filler(s) used.

The titanate~ bondins agent~ are tho~@ a~ de~cribed in the Modern Plastic Encyclop~dia, 1986-87, pp. 128 ~ 130, or the lika.

The isocyanateY ar~ such as polymethylene polyphenylisocyanate (PMPPIC), 1,6 hexamethyl~ne di-lsocyanate & NCO-(C~2)6-NCO, 2,4 toluene di-isocyanate or their oligomer~ or the like.

~ he pro~Qrred bonding agent3 to be u~ed in th~ exam~le~ of thein~tant in~ntion are gamma-aminopropyltriethoxy3ilane (A-1100, Union Carbid~), and linear polymethylene polyphenyli~ocyanate (PMPPIC).

Free radicals can be generated for th~ purpose of forming interfacial strong ~ontin~, such a~ the covalent bonds. The free ; .

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radical initiator(R) may b~ that from radiation sources, such as gamma radiation, ultraviolet radiation, las~r radiation, microwave radiation, the ultrasonic or the like. .The chemical initiation may bs from any catalytic initiator causing ~ree radical reactions, among which are the chemical initiators listed in the polymer Hand ~ook, Interscience 1966, pp. II-:3 to II-51, or the like.

The preferred chemical intiators for carrying out the example~
of the current invention are the chemical~ used for the known xanthation proce~ for graft polymeri~ation of vinyl monomer~ onto celluloses, ceric ammonium sulfate, odium bisulfite, peroxides, or the like.

The ethylenically unsaturated carbo~ylic acid or acid anhydride may be added as auxiliarie or a~ other sorts o~ bonding agentq to be used in the practice of the current inv~ntion, such as maleic acid, maleic anhydride, lineolenic acid, furmaric acid, citraconic acid, or itaconic acid, or the like. Mal~ic anhydride is the preferr~d au~iliary agent. Mo~ocarboxylic acids, uch as acrylic ac d or methacrylic acid, may alco be used.

In~tead of maleic anhydride, polymaleic anhydride, succinic anhydride may also be used.

The inorganic fillers and the other polym~ric fiher~ ar~ -quch as the hydroxyl containing group, sllica, silic~ous aggregates, 1~

~ ..3.3~j sand stones, dolomitic sand stones, calcium carbonate, kaolin, talc, clay, mica, glass fibers, glass spheres, glass flakes, ash, wollastonite, carbon black, graphite fibers, metal fibers, metal powders, metal hydrides, metal oxides partially dehydrated or not, metal compounds, diatomaceous earth, silica, aramide, potassium, titanate fibers, polypropylene fibers, nylon fibers, aramide fibers, or the like, in either purified or unpurified form.

The preferred inorganic agsregate~ used in the examples of the currenct invention are: broken stones, crushed or uncrushed gravels or the like.

other additives are optionally added, such as colorant3, antioxidants, lubricants, plasticizers, pigments, opacifiers, heat stabilizers,impact modifiers,photostabilizers, antistatic agents, biostabilizers, crystal nucleating a~ents, or the like.

As concerns the weight percentages for the Asphalt composite constituants of the present invention, may be as follows:

- Bitumen Asphalt................ from 1 to 98 wt. %, (based on the total composition weight) - Cellulosic fibers............. from 0.1 to 99 wt.%, (based on the total composition weight) - Polymerizable functional monomer(s) or functional oligo-mer(s)........................ from 0.5 to 300 wt%, ' " ' :

' (based on the cellulosic filler's weight) - Bonding a~ent(s)......................... from 0.001 to 20 wt%, (based on the cellulosic filler's weight) - Inorganic-filler aggregates and/or other polymeric fibers ....................................... from 0 to 99.5 wt.%
(based on the composition weight) - Acid anhydride.............................. from 0 to 10 wt.%, (based on the filler's weight~
- Chemical initiator(s)....................... from 0 to 10 wt.%, - Plasticizer(s).............................. from 0 to 60 wt.%, (based on the matrix weight) An Asphaltic composite material may be made, according to the current invention, by compounding from 1 to 99 wt.% of cellulosic fibers and from 1 to 99.9 wt.~ of Asphaltic material to bond with each other by coating and/or by graiting, or co-grafting said cellulosic fibers with 0.5 to 300 wt.% of polymerizable functional monomer or functional oligomer and/or with 0.001 to 20 wt.% of a bonding agent. Same composite material may additionally comprise from 0 to 10 wt.% catalytic initiator, from 0 to 10 wt.% ethyleni-cally unsaturated acid or acid anhydride. It may also comprise from 0 to 99.5 wt.% inorganic filier or aggregates and/or other polymeric fi~ers and from 0 to 60 wt.% plasticizers. Said composite material is also optionally comprising colorants, antioxidants, stabilizers, flame-retard0nts, lubricants, pigments, , : ' - ' ~' .. . .

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opacifiers,impact-modi~iers,photo-stabilizers, ant.istaticagents, and crystal nucleating a~ents, or the like.

The cellulosic fibers may be impregnated, or grafted, ~r co-graphted first with said polymerizable functional monomers or functional oligomers by a known free radical process, or by any graft-polymerization process leading to form interfacial strong bonding such as covalent bonding.

The bonding agent may coat said cellulosic fibers or may graft them by a free radical generating process via the effect of any initiating source as mentioned before.

The co-grafting of said both polymerizable monomer or oligo-mer and said bonding agent onto said filler may be carried out simultaneously or successively. The simultaneous grafting is recommended for the industrial economy.

~ he inorganic filler or aggregates or the other polymeric fibers may be mixed with the cellulosic fibers before the addtion step(s) oP said polymerizable and said surface bonding agent(s).
Said mixing may also be during or after said addition.

The inorganic filler may also be bonded or coated with the said polymerizables and/or with said bonding agents before, during or after the mixing steps.

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The experimentation results in the examples of the current invention could be improved or be reached their optimum values by changing the preparation conditions, an~/or the weight percentages of the applied materials or the substances.

This invention will now be furtherly described by non limiting examples:

EXA~PLES:
E~am~le 1:
a) (i) Impregnating 50 g of dry chemical thermomechanical wood pulp der.ived from aspen and ground at 20 mesh, and ordinary wood saw dust (20 mesh), with 5 g of polystyrene (by follow-ing a solvent evaporation process): to give impregnated pulp or saw dust with 10% polystyrene.

(ii) Compounding the above prepared wood pulp and saw dust with 300 g of hot molten (at 120 C) Asphalt Cement of srade 85/100 by stirring for 5 minutes.

b) 60 g of the above hot molten (at 120 C) asphaltic composition of a) was pourred on 990 g of hot coarse (at 150 C) and fine standard paving road aggregates (35/65 of ratio), mixed well and molded for carrying stability and follow marshall tests in addition to density and voids analyses.

c) 10 g of the above prepared wood pulp and saw dust of a) are well mixed with 990 g hot (at 150 C) standard aggregates of b). The whole mix are compounded with 50 g of the hot molten asphalt cement of grade 85/100, then molded for same tests.

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All the tests are compared with same results of samples prepared as per c ), but in absence of the said prepared wood pulp and wood saw dust.

Example 2:
The methods oE preparations and tests as per Example 1 are carried out, provided the aspen pulp and the saw dust are only coated with 2~ by weight of gamma-aminopropyltrimethoxy silane (A-1100) (in ethanol solvent, then evaporated).

E~ample 3:
The experimentation and testing methods as per Example 1, but the aspen pulp and the saw dust are grafted with 2% of silane A-llOO as per the US Patents 4,717,742 or 4,820,749.

Exam~le 4:
The same experimentation and tests as per Example 1, but here the aspen pulp and the saw dust are pre-coated with 2% by weight of polymethylene polyphenylisocyanate (PMPPIC) by using acetone solvent, then evaporated.

Example 5:

The same experimentation and testing methods are as per Example 1, but here the aspen pulp and the saw dust are pre-grafted with styrene monomer (by a grafting load of 10~ by weight), that is by following the ~anthate method (as per the ;~ ' ~.. .
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2 ~ 8 9 Belgium Pat. 646,284, Oct. 1964 and th~ British Pat.
1,059,541). -Exam~le 6.The experimentation and testing methods are as per Example 1, but here the aspen pulp and the saw dust are pre-grafted with styrene as per Example S and then co-grafted with silane A-2~389 Variou~ modifications and variations of the invention wil 1 bereadily apparent to those skil led in the Art. It is to be understood that such modifications and variations are to be included within the purview o~ this invention and the spirit o~
the present cl aims .

Claims (19)

1. As asphaltic composite material is characterized by com-pounding from 0.1-90 wt.% of cellulosic or lignocellulosic fibers, from 1-98 wt.% of asphaltic material to bond with each other by applying an impregnating, a coating, a grafting, a grafting-coating, a coating-grafting or a co-grafting process onto said cellulosic or lignocellulosic fibers by using from 0-300 wt.% of polymerizable functional monomer or functional oligomer and with from 0-20 wt.% of organo or organo-metallic bonding agent, in presence of from 0-10 wt.% of a catalytic initiator (based on the cellulosic or lignocellulosic fibers weight); said composite material is additionally comprising from 0-95 wt.% of an inorganic filler and/or organic polymeric fibers.

2. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are impregnated with a synthetic polymer.

3. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are grafted with a polymerizable functional monomer of functional oligomer.

4. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are coated with said organo or organo-metallic bonding agent.

5. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are grafted with said organo or organo-metallic bonding agent.

6. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are grafted with said polymerizable functional monomer or functional oligomer and coated with said organo or organo-metallic bonding agent.

7. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are grafted with said organo or organo-metallic bonding agent and coated with said polymerizable functional monomer or functional oligomer.

8. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are co grafted with said polymerizable functional monomer or functional oligomer and with said organo or organo-metallic bonding agent.

9. The composite material as defined in claim 1, wherein the polymerizable functional monomer or functional oligomer is selected from styrene, methylmethacrylate, ethylacrylate, acrylonitrile, acrylic acid and methacrylic acid.

10. The composite material as defined in claim 1, wherein the organo or organo-metallic bonding agent is selected from the group consisting from organo-silicone compounds, organo-titanium compounds, organo-zirconium compounds, organo-alluminium compounds, isocyanate bonding agents, stearate bonding agents, maleate bonding agents, abietic acid and linoleic acid.

11. The composite material as defined in claim 1 or 10, wherein the bonding agent is selected from the group consisting of gamma-aminopropylethoxysilane and polymethylenepolyphenyl-isocyanate.

12. The composite material as defined in claim 1, wherein the cellulosic or lignocellulosic fibers are selected from the group consisting of wood saw dust, ground wood, wood pulps, agricultural cellulosic fibers, cotton fibers or flakes, flax fibers, rayon, bamboo fibers, bagasse, rice hulls, nut shells, wood shavings, wood boards, wood pannels, wood structures, paper, papers, cartons, cellulosic cloth and their wastes.

13. The composite material as defined in claim 1 or 12, wherein the cellulosic or lignocellulosic fibers are selected from the group consisting of chemicalthermomechanical wood pulp derived from aspen and wood saw dust.

14. The composite material as defined in claim 1, wherein the asphaltic material is selected from the group consisting of native asphalt, solvent asphalt, emulsion asphalt, petroleum asphalt, bitumen, asphaltic bitumen, bitumeneous asphalt, asphalt additive, metallic asphalt, pitch, trinided pitch, mineral pitch, gilsonite, modified asphalt, bonding agent asphalt, polymeric asphalt and rubber asphalt.

15. The composite material as defined in claim 1, wherein the inorganic filler material and the organic polymeric fibers are coated or bonded with said polymerizable functional monomer or functional oligomer and/or with said organo or organo-metallic bonding agent.

16. The composite material as defined in claim 1 or 15, wherein the inorganic filler material and the organic polymeric fibers are selected from the group consisting of silica, siliceous aggregates, sand stones, dolomite sand stones, calcium carbonate, kaolin, talc, clay, mica, glass fibers, glass spheres, glass flakes, ash, wollastonite, carbon black, graphite fibers, metal fibers, metal powders, metal hydrides, metal oxides partially hydrated or not, metal compounds, diatomacous earth, silica, aramide, potassium, titanate fibers, aramide fibers, polypropylene fibers and nylon fibers.

17. The composite material as defined in claim 1, wherein the catalytic initiator is selected from the organic peroxides.

18. The composite material as defined in claim l1or 17, wherein the organic peroxide is dicumylperoxide.

19. The composite material as defined in claim 1, wherein the ethylenically unsaturated acid or acid anhydride is selected from maleic anhydride.