Fiber products with a coating formed from aqueous polymer dispersions

Abstract

The present invention relates to textile fibre products having a coating comprising polymers based on ethylenically polymerisable monomers with a glass transition temperature of at least 60 and a coating method for coating fibre products with an aqueous polymer dispersion, wherein an aqueous polymer dispersion based on vinyl polymerisable monomers with a glass transition temperature of at least 60 C. is firstly provided, and this is brought into contact with a fibre product and then dried. The invention also relates to the use of corresponding polymer dispersions for the coating of fibre products, correspondingly coated fiber products, use thereof to reinforce mineral matrices, and corresponding fibre-composite materials, in particular textile-concrete composite materials. In particular, the invention relates to a coating means that can be applied to a textile fabric in a continuous, water-based process and enables an optimal introduction of force from the mineral matrix into the textile reinforcement.

Claims

1. A composite material made of a textile fibrous product having a coating comprising from 5% by weight to 100% by weight of an applied material, based on the gross mass of the fibrous product, wherein the material comprises from 20 to 100% by weight of polymers based on ethylenically polymerizable monomers, and wherein at least a portion of the monomers comprise basis monomers A that are selected from the group consisting of vinyl-aromatic monomers and C.sub.1 to C.sub.24 (meth)acrylates, the polymers have a glass transition temperature of at least 60 C.; from 0 to 80% by weight of cross-linking components; and from 0 to 20% by weight of other additives; within a concrete matrix.

2. The composite material according to claim 1, wherein said textile fibrous product is a textile fibrous product with a coating comprising from 10 to 60% by weight of the applied material based on the gross mass of the fibrous product.

3. The composite material according to claim 1, wherein said ethylenically polymerizable monomers are vinylically polymerizable.

4. The composite material according to claim 1, wherein said polymers can be obtained from a monomer composition, wherein said monomer composition contains from 5% to 100% of the basis monomers A, from 0% to 50% of functional monomers B, and from 0% to 30% of cross-linking monomers C, based on the total mass of the monomer composition, wherein the functional monomers B are selected from the group of (meth)acrylic acid, C.sub.2 to C.sub.8 hydroxyalkyl (meth)acrylates, C.sub.2 to C.sub.8 (alkyl)aminoalkyl (meth)acrylates, sulfonated monomers, phosphated monomers and vinylpyridines, the cross-linking monomers C comprise at least two ethylenically unsaturated non-conjugated groups, N-methylol groups, and/or epoxy groups.

5. The composite material according to claim 4, wherein the cross-linking components comprise monomers C and/or external cross-linkers having reactivity towards the functional monomers B.

6. The composite material according to claim 1, wherein said textile fibrous product comprises one-dimensional textile structures, two-dimensional textile sheets, and/or three-dimensional textile steric structures.

7. The composite material according to claim 1, wherein said textile fibrous product comprises carbon fibers, glass fibers, basalt fibers, aramid fibers, polyethylene fibers, and/or polypropylene fibers, including mixtures thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is illustrated and described herein with reference to the various drawings, in which like reference numbers denote like method steps and/or system components, respectively, and in which:

(2) FIG. 1 is a test speciment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) In a first embodiment, the object according to the invention is achieved by a textile fibrous product having a coating comprising from 5% by weight to 100% by weight of applied material, based on the gross mass of the fibrous product, wherein the material comprises

(4) from 20 to 100% by weight of polymers based on ethylenically polymerizable monomers having a glass transition temperature of at least 60 C.,

(5) from 0 to 80% by weight of cross-linking components; and

(6) from 0 to 20% by weight of other additives.

(7) Preferably, the coating comprises from 10 to 60% by weight of the applied material.

(8) Preferably, the polymerizable monomers are vinylically polymerizable.

(9) In a preferred embodiment, the polymers can be obtained from a monomer composition, wherein said monomer composition contains from 5% to 100% of basis monomers A, from 0% to 50% of functional monomers B, and from 0% to 30% of cross-linking monomers C, respectively based on the total mass of the monomer composition, wherein, in particular, the basis monomers A are selected from the group of vinyl-aromatic monomers and C.sub.1 to C.sub.24 alkyl (meth)acrylates, especially the functional monomers B are selected from the group of (meth)acrylic acid, C.sub.2 to C.sub.8 hydroxyalkyl (meth)acrylates, C.sub.2 to C.sub.8 (alkyl)aminoalkyl (meth)acrylates, sulfonated monomers, phosphated monomers and vinylpyridines, especially the cross-linking monomers C comprise at least two ethylenically unsaturated non-conjugated groups, N-methylol groups, and/or epoxy groups.

(10) Preferably, the cross-linking components comprise monomers C and/or external cross-linkers having reactivity towards the functional monomers B, especially those selected from the group of di-, tri- and/or polyfunctional unblocked or blocked isocyanates, epoxysilanes, formaldehyde resins, melamine resins, carbodiimides, and epoxy resins. These components react with the other components of the coating to undergo cross-linking.

(11) The fibrous product according to the invention preferably comprises one-dimensional textile structures, two-dimensional textile sheets, and/or three-dimensional textile steric structures.

(12) Preferably, the fibrous product according to the invention comprises, or consists of, carbon fibers, glass fibers, basalt fibers, aramid fibers, polyethylene fibers, and/or polypropylene fibers, including mixtures thereof.

(13) In an alternative embodiment, the object according to the invention is achieved by a process for coating fibrous products with an aqueous polymer dispersion, especially for producing the fibrous products according to the invention, comprising i) providing an aqueous polymer dispersion that contains a polymer based on ethylenically, especially vinylically, polymerizable monomers having a glass transition temperature of at least 60 C. and optionally a suitable material for cross-linking the polymer; ii) contacting a fibrous product with said aqueous polymer dispersion; and iii) drying the thus coated fibrous product, especially at room temperature or an elevated temperature of up to 220 C.

(14) In the prior art to date, almost exclusively SBR and polychloroprene types have been employed for coating fibrous products with aqueous polymer dispersions, based on the argument that these are highly resistant in an alkaline environment. Now, within the scope of the present invention, it has been surprisingly found that certain dispersions of polymers, for example, based on (meth)acrylic monomers and/or styrenic monomers, also have a sufficiently high resistance to alkali. Surprisingly, aqueous dispersions of polymers having a glass transition temperature of at least 60 C. based on vinylically polymerizable monomers, optionally in combination with external cross-linkers, are well suitable for the coating of fibrous products for use in textile-concrete composite systems, which have the above mentioned properties.

(15) Preferably, the glass transition temperature of the polymers in the dispersion employed is at least 70 C.

(16) In a preferred embodiment of the process according to the invention, one-dimensional textile structures, two-dimensional textile sheets, and/or three-dimensional textile steric structures are employed as the fibrous product.

(17) Suitable one-dimensional textile structures include, for example, yarns, ravings, threads and/or ropes, without being limited thereto. Suitable virtually two-dimensional textile sheets include, for example, non-woven scrims, woven fabrics, loop-formingly knitted fabrics, loop-drawingly knitted fabrics, stitch-bonded fabrics, non-woven fabrics and/or felts, without being limited thereto.

(18) In a preferred embodiment of the process according to the invention, said fibrous product includes carbon fibers, glass fibers, basalt fibers, aramid fibers, polyethylene fibers, and/or polypropylene fibers. In particular, the fibrous product consists of fibers of one of these fiber types, or mixtures thereof.

(19) Said contacting of the aqueous polymer dispersion and the fibrous product according to the invention can be effected in any way known from the prior art. Preferably, the fibrous product is contacted with the aqueous polymer dispersion by applying a continuous or discontinuous textile application method from the prior art. Particularly preferred application methods include soaking, mist-spraying, dipping, casting and/or jet-spraying, the invention not being limited to such methods. The thus achieved applied mass of material, based on the gross mass of the fibrous product, is from 5% by weight to 100% by weight, preferably from 10% by weight to 60% by weight, more preferably from 25% by weight to 50% by weight, even more preferably from 30% by weight to 40% by weight.

(20) In a preferred embodiment of the process according to the invention, the proportions of the components of said aqueous polymer dispersion are selected to obtain a solids content of from 10% by weight to 70% by weight, more preferably from 25% by weight to 60% by weight, even more preferably from 40% by weight to 50% by weight, based on the total mass of the polymer dispersion. The solids proportion of the dispersion preferably contains from 20 to 100% by weight of polymer, from 0 to 80% by weight of cross-linker, and from 0 to 20% by weight of other additives, based on the solids fraction of the dispersion, the percentages summing up to 100%.

(21) In addition to the main components described, the aqueous dispersion according to the invention may optionally contain further auxiliaries and additives known from the construction, textile and coatings industries, including but not limited to leveling auxiliaries, wetting agents, defoamers, debubbling agents, organic and inorganic thickeners, tackifying resins, fillers, pH regulators, and/or preservatives.

(22) In a preferred embodiment of the process according to the invention, the aqueous polymer dispersion based on vinylically polymerizable monomers is provided by suitable continuous, semi-continuous or discontinuous polymerization methods known from the prior art. Particularly preferred are emulsion polymerization, suspension polymerization, or dispersion polymerization. Even more preferably, the polymer dispersion is obtained by emulsion polymerization, which is technically established and has been described many times (Hans-Georg Elias, Makromolekle Volume 3 Industrielle Polymere and Synthesen, 6th Edition, Wiley-VCH). The polymer dispersion can be stabilized with the surfactants commonly used in the prior art, such as anionic surfactants, non-ionic surfactants, and/or protection colloids, and mixtures thereof, without the invention being limited thereto. For the initiation of the polymerization reaction, any suitable type of initiators may be used, including but not limited to peroxides, azo compounds and/or redox initiator systems. Further, reactants may be employed that are typically used in such a process, including but not limited to electrolytes, agents for adjusting the pH, and/or chain regulators/transfer agents.

(23) In a preferred embodiment of the invention, the aqueous polymer dispersion is provided by polymerization of a monomer composition containing from 5% by weight to 100% by weight of basis monomers A, from 0% by weight to 50% by weight of functional monomers B, and from 0% by weight to 30% by weight of cross-linking monomers C, respectively based on the total mass of the monomer composition.

(24) Suitable basis monomers A include, in particular, C.sub.1 to C.sub.24 alkyl esters of acrylic and methacrylic acids, as well as vinyl-aromatic monomers, such as styrene, a-methylstyrene, or vinylpyridine. These monomers can be employed alone or in any admixture thereof in such a way that the glass transition temperature of the resulting polymer is at least 60 C. The latter can be estimated from the glass transition temperatures of the monomers to be employed by means of the Fox equation (T. G. Fox, Bull, Am. Phys. Soc. 1, 123 (1956)) or Pochan equation (J. M. Pochan, C. L. Beatty, D. F. Hinman, Macromolecules 11, 1156 (1977)) as known to the skilled person.

(25) In particular, the following monomers having a reactive group can be employed alone or in admixture as functional monomers B: (meth)acrylic acid, C.sub.2 to C.sub.8 hydroxyalkyl(meth)acrylates, such as hydroxyethyl methacrylate, C.sub.2 to C.sub.8 (alkyl)aminoalkyl (meth)acrylates, such as dimethylaminoethyl methacrylate, sulfonated monomers, such as sodium styrenesulfonate, phosphated monomers, such as monoacrvloxyethyl phosphate, and/or vinylpyridines. The invention is not limited to the mentioned functional monomers. Each suitable functional monomer from the prior art can be employed. Suitable monomer are those in which the glass transition temperature of the resulting polymer is at least 60 C.

(26) Monomers comprising at least two ethylenically unsaturated non-conjugated groups, N-methylol groups and/or epoxy groups are preferably employed as cross-linking monomers C. Suitable monomers include divinyl and polyvinyl monomers, such as divinylbenzene, di- or poly(meth)acrylates, di or polyallyl ethers, and di- or polyvinyl ethers of diols or polyols. Further, monomers may be employed that can still lead to cross-linking after the soaking process and the forming of the coating without an external cross-linker having to be added, such as N-methylolamide and/or glycidyl methacrylate.

(27) In addition, an external cross-linker may be added to the aqueous polymer dispersion provided according to the invention, in order to improve the mechanical properties of the coated fibrous products and the composite properties of the resulting textile-concrete composites. Preferably, it has a reactivity matching that of the functional groups present in the polymer dispersion. For example, but without limitation, there may be employed blocked and unblocked polyisocyanates, carbodiimides, aziridines, epoxy resins, epoxysilanes, formaldehyde resins, urea resins, reactive phenol resins, without being limited thereto. Their application in the coating system is effected by mixing the polymer dispersion and the external cross-linker immediately before the contacting of the fibrous product and the aqueous polymer dispersion.

(28) In an alternative embodiment, the object of the invention is achieved by a coated fibrous product obtainable by the coating process according to the invention. Preferably, the fibrous product according to the invention is obtainable by one of the preferred embodiments of the process according to the invention. Preferred embodiments of the process steps and of the reagents employed may also be combined.

(29) The coated fibrous products according to the invention have an excellent tensile strength and bonding strength in the concrete and may thus be employed as a reinforcement of concrete to particular advantage. Thus, carbon fibers coated according to the invention show a comparable level of tensile strength and of extraction force from the concrete as that of an epoxy resin system corresponding to the prior art (cf. Table 1, entry 2, versus Table 3, entries 1-5). Thus, the use of such fibrous products is not exclusively, but particularly advantageous to the reinforcement of concrete and/or cement products. Further fibrous products coated according to the invention can be used for reinforcing existing concrete structures that are employed in the outdoor field (for example, facade plates or other exterior constructions) and exposed to temperatures or weathering conditions of up to 100 C.

(30) A coating according to the invention based on said aqueous polymer dispersion is also highly interesting for use on hydrolytically sensitive fibrous materials, such as glass or basalt fibers. From the measured values shown in Table 3, entries 6 and 7, it is clear that good tensile strengths of the coated rovings are achieved at room temperature and at 100 C. These are clearly above the values achieved by coating with polymer dispersions not according to the invention (Table 2, entries 6 and 7). According to the manufacturer, the glass fiber used in the Examples passes class II of the so-called SiC tests (Strength in Concrete, EN 14649). In these tests, glass fibers are embedded in concrete and stored at 80 C. and 80% relative humidity for 96 hours. In the subsequent test, the residual strength for granting class II must be at least 350 MPa for a starting strength of 1000 MPa, i.e., the decline may be 65% at most. If this glass fiber is coated according to the invention (see Table 3, entry 6), a significant increase of stability to alkali is achieved, because the decline of strength is only 35%. With basalt fibers coated according to the invention (Table 3, entry 7), the decline is 60%.

(31) This shows that an aqueous polymer dispersion provided according to the invention surprisingly has a good resistance to alkali and is therefore excellently suitable for use as a coating of textile reinforcements for cement-bonded matrices. Table 3 states the values of extraction strengths of carbon fibers coated according to the invention in concrete (entries 1-5) at room temperature and at 80 C. In both cases, excellent values are achieved that are on the level of epoxy-coated fibers according to the prior art. Table 3 also states the corresponding values for glass fibers resistant to alkali (AR glass) (entry 6). These values are significantly higher than, for example, the values stated in the patent EP 2 004 712 B1.

(32) Fibrous products made of carbon fibers and coated according to the invention also proved to be windable about a roller with a diameter of 20 cm along the machine running direction over a 12k roving.

(33) In another embodiment, the object of the invention is achieved by the use of an aqueous polymer dispersion as provided in the above described process according to the invention as a coating agent for fibrous products. The aqueous polymer dispersion employed may have all the preferred features of the polymer dispersion employed in the process according to the invention. The use according to the invention enables the production of fibrous products according to the invention with the described advantages.

(34) In another embodiment, the object of the invention is achieved by a composite material comprising a fibrous product coated according to the invention and a mineral matrix, especially a concrete matrix. More preferably, a composite material is made of a fibrous product according to the invention in a mineral matrix, especially a concrete matrix. In particular, the composite material according to the invention is a textile-concrete composite with the above described advantages of the invention. In particular, the composite material comprises a fibrous product according to the invention in the form of a one-dimensional textile structure, a two-dimensional textile sheet, and/or a three-dimensional textile steric structure.

(35) In another embodiment, the object of the invention is achieved by the use of the coated fibrous products according to the invention, especially in the form of one-dimensional textile structures, two-dimensional textile sheets, and/or three-dimensional textile steric structures, for reinforcing mineral materials, especially for reinforcing concrete components. The use according to the invention enables the provision of the composite materials according to the invention with the above described technical advantages.

EXAMPLES

(36) Using the process according to the invention, coated fibrous products and corresponding textile-concrete composite materials resulting therefrom were prepared. For this purpose, the polymer dispersions according to the invention were at first applied to carbon fibers of the type 3200tex from TohoTenax by soaking, followed by drying at 160 C. From the fibrous products obtained according to the invention, test specimens for determining the tensile strength at room temperature (RT), at 100 C. and after storage on alkali were prepared (see characterization methods/tensile test). Further, textile-concrete composite materials were prepared by embedding the fibrous products coated according to the invention in fine-grained concrete (test specimen see FIG. 1), and subjected to an extraction test (see characterization methods/extraction test).

(37) In the same way, Examples with glass and basalt fibers as well as Comparative Examples with polymer dispersions not according to the invention and polymers from the prior art were performed.

(38) The following measurements were performed: Tensile tests with the coated rovings at room temperature RT, at 100 C. and after storage in alkaline medium (ETAG004), extraction tests with the textile-concrete composites at room temperature RT and at 80 C. Table 1 shows the results of these tests for examples of the prior art. Table 2 shows the test values obtained for test specimens not prepared according to the invention. Table 3 summarizes the corresponding test values for test specimens prepared according to the invention.

(39) In the following, the materials employed and the performance of the tensile test and extraction test experiments are described in more detail.

(40) Materials Employed:

(41) Rovings/Yarns:

(42) carbon fiber of type 3200tex from TohoTenax basalt fiber of type 2400tex from Deutsche Basalt Faser GmbH alkali resistant glass fiber of type 2400tex from Owens Coming
Fine-Grained Concrete:

(43) In a planetary agitator, 115 g of water and 1 kg of Pagel TF 10fine-grained concrete made from Portland cement were charged, and mixed for 5 min (according to the Technical Data Sheet of the concrete employed).

(44) Polymer Dispersions:

(45) Commercially available products may be employed as polymer dispersions. In the stated Examples, model polymers were prepared by a classical semi-continuous emulsion polymerization process. The polymer dispersions all have a solids content of 47% by weight. In order to prepare polymers having a high glass transition temperature of 60 C. and more according to the invention, monomer compositions having a high proportion of monomers that result in hard polymers, for example, styrene, were selected. Accordingly, polymers not according to the invention contained higher proportions of soft comonomers, for example, ethylhexyl acrylate. The exact composition for a particular glass transition temperature was estimated by means of the Fox equation, and confirmed by DSC measurements after the synthesis. The amount coated onto the fibers employed was at about 30% by weight for all aqueous binder dispersions employed.

(46) The components of the epoxy resin system are based on commercially available cycloaliphatic epoxide with a cycloaliphatic amine as a hardener. The system was free of solvent and water. The amount coated was about 50% by weight of solids on the fiber after drying.

(47) Cross-Linkers:

(48) Cross-linker 1: blocked polyisocyanate from the company Covestro

(49) Cross-linker 2: reactive polyisocyanate from the company Covestro

(50) Characterization Methods

(51) Coating of the Yarn

(52) Yarns made of carbon, glass or basalt fibers may be used as the yarn to be finished. The yarns are coated or soaked in a manual process. During the coating, from 10 to 60% by weight of polymer is applied to the fiber. The thus coated yarn is subsequently dried at 160 C.

(53) Tensile Test

(54) DIN EN ISO 527-4 and DIN EN ISO 527-5 are the standards for fiber-reinforced materials (ERNI) relevant in Europe. The two standards only describe the tensile test of the FRMs. In this test, the stress/strain behavior in the limiting states 0 and 90 orientation of the fiber reinforcement is measured in order to be able to determine characteristics such as Poisson's ratio v, tensile strength sM, elongation at break eM, and the modulus of elasticity.

(55) In plastics testing, the tensile test has a priority meaning and is considered a basic experiment under the quasistatic or static testing conditions.: crosshead is run at a constant speed according to the standard DIN EN ISO 527-4. The FRM usually show a hard and brittle behavior. Therefore, the tensile strength sM and the yield stress sY are the same. The breaking stress sB can fall on the same point. The test specimen type 1B from DIN EN ISO 527-4 is mainly used for fiber-reinforced thermoplasts and thermosets. The test specimen employed orients itself by it.

(56) The materials are tested under three conditions: at room temperature, at 100 C., and after storage in alkaline medium. For the latter examination, the specimens are stored at 45 C. in a solution with pH 13.7 for 14 days, and tested at 45 C. without previous drying. The test solution orients itself by the solution in the composition described in ETAG004.

(57) Extraction Test

(58) In the general building approval by the Deutsches Institut fr Bautechnik in der Bundesrepublik Deutschland (abZ) No. Z-31.10-182, the testing of the bonding strength of the textile towards fine-grained concrete is described. In this test, a textile-reinforced test specimen is loaded. The introduction of the force is effected through the clamping on the upper and lower sides of the test specimen. The textile reinforcement is oriented in the direction of load in the test specimen (0 with the direction of load). For evaluation, the maximum machine force F.sub.max is employed. For the characterization of the fiber strand specimens, a method analogous to the above method is used. It is also described elsewhere (State-of-the-Art report of RILEM Technical Committee TC 201-TRC; EP 2 004 712 B1) for characterizing the bonding strength between the yarn and textile. The coated yarns were embedded in concrete with dimensions of widththickness=5 cm6 cm with a concrete thickness of 1 cm in midway, as shown in FIG. 1. A concrete coverage of 0.5 cm was used by analogy with abZ No. Z-31.10-182. The coated yarns were prepared with 1.5 cm protrusion beyond the concrete in the extraction direction, in order to ensure that the bonding area to the concrete always remains the same during the testing. The test conditions were chosen by analogy with abZ No. Z-31.10-182. The test speed is 1 mm/min to 3 mm extraction length, and 5 mm/min from 3 mm extraction length, until extraction is complete. The test specimens are measured at room temperature and at 80 C. The maximum extraction force F.sub.max is evaluated.

(59) TABLE-US-00001 TABLE 1 References to the prior art Extraction Tensile Tensile Tensile Extraction strength Functionality Internal External strength strength strength strength F.sub.max Fiber Chemical Tg of cross- cross- RT ETAG004 F.sub.max F.sub.max RT 80 C. type structure.sup.1 [ C.] polymer linker linker [MPa] [MPa] [MPa].sup.4 [N] [N] 1.sup.2 Carbon SBR 10 carboxy melamine 2500 2400 2400.sup.4* 660 180 resin 2.sup.3 Carbon EP 100 3500 2700 3300 >1500.sup.5 >1500.sup.5 .sup.1SBR = styrene-butadiene rubber, EP = epoxy resin .sup.2aqueous SBR dispersion Lefasol VL 90/1 (Lefatex) .sup.3cycloaliphatic epoxide cured with cycloaliphatic amine, T.sub.g = 100 C. .sup.4tensile strength at 45 C. after storage in concrete pore solution, pH 13.7, for 14 days without drying .sup.4*tensile strength at RT for a coated roving after storage in concrete pore solution (pH 12.8) for 7 days with drying .sup.5concrete cracked along the load during the testing because of too high bonding strengths

(60) TABLE-US-00002 TABLE 2 Examples not according to the invention Extraction Tensile Tensile Tensile Extraction strength Functionality Internal External strength strength strength strength F.sub.max Fiber Chemical Tg of cross- cross- RT 100 C. ETAG004 F.sub.max RT 80 C. type structure.sup.1 [ C.] polymer linker linker [MPa] [MPa] [MPa].sup.3 [N] [N] 1 Carbon ACR 10 2900 2200 2800 520 78 2 Carbon ACR 40 3700 2400 2900 580 170 3 Carbon ACR 5 Hydroxy 3100 2400 2800 800 410 4 Carbon ACR 5 Hydroxy Cross- 2900 2500 3100 680 340 linker 1 5 Carbon ACR 8 PETA.sup.2 2600 2000 2200 700 280 6 AR ACR 5 Hydroxy Cross- 950 560 580 660 360 linker 1 7 Basalt ACR 5 Hydroxy Cross- 990 930 360 220 96 linker 1 .sup.1ACR = pure acrylate, SAC = styrene acrylate .sup.2PETA = pentaelythritol triacrylate .sup.3tensile strength at 45 C. after storage in concrete pore solution, pH 13.7, for 14 days without drying

(61) TABLE-US-00003 TABLE 3 Examples according to the invention Extraction Tensile Tensile Tensile Extraction strength Functionality Internal External strength strength strength strength F.sub.max Fiber Chemical T.sub.g of cross- cross- RT 100 C. ETAG004 F.sub.max RT 80 C. type structure.sup.1 [ C.] polymer linker linker [MPa] [MPa] [MPa].sup.3 [N] [N] 1 Carbon ACR 70 3900 2700 3200 940 930 2 Carbon SAC 115 3300 2800 2900 1000 100 3 Carbon SAC 105 Hydroxy 3500 3000 3400 >1500.sup.4 >1500.sup.4 4 Carbon SAC 105 Hydroxy Cross- 3900 3000 3600 >1500.sup.4 >1500.sup.4 linker 2 5 Carbon ACR 105 PETA.sup.2 3200 2900 3100 >1500.sup.4 >1500.sup.4 6 AR SAC 15 Hydroxy Cross- 910 790 590 910 760 glass linker 2 7 Basalt SAC 105 Hydroxy Cross- 1100 1100 430 1000 1000 linker 2 .sup.1ACR = pure acrylate, SAC = styrene acrylate .sup.2PETA = pentaelythritol triacrylate .sup.3tensile strength at 45C. after storage in concrete pore solution, pH 13.7, for 14 days without drying .sup.4concrete cracked along the load during the testing because of oo high bonding strengths