CN103713009A - Method for determining coefficient of thermal expansion - Google Patents

Abstract

The invention relates to a method for determining a coefficient of thermal expansion. The method comprises the steps of determining a spectral peak movement amount of a to-be-detected sample caused by the variation of unit temperature to be recorded as ChiF; mixing the detected sample and polymer to obtain a mixture, and ultrasonically dispersing the mixture to obtain a composite material; determining a second spectral value of the composite material under a surface strain value by utilizing a strain determining device and a spectral system, linearly fitting the surface strain value and the second spectral value, determining the spectral peak movement quantity of the detected sample, which is caused by the unit strain and is parallel to the strain direction to be recorded as SO; determining the spectral peak movement amount of the detected sample in the composite material caused by the unit temperature variation by utilizing the spectral system to be recorded as ChiC; calculating the coefficient of the thermal expansion of the detected sample according to the following formula if the coefficient alpha E of the polymer is known: alpha F=alpha E-(ChiC-ChiF)/SO. The method is simple, convenient in determination and capable of rapidly and accurately determining the coefficient of the thermal expansion of the detected sample.

Description

The assay method of thermal expansivity

Technical field

The present invention relates to material parameter determination techniques field, particularly relate to a kind of assay method of thermal expansivity.

Background technology

Carbon nanomaterial, if carbon nano-tube, Graphene etc. are due to its excellent physicochemical property, has broad application prospects.For the larger occasion of temperature variation in materials processing forming process or under working condition, if not mating, the matrix thermal expansivity that carbon nanomaterial is in contact with it will not cause unrelieved stress to produce, when serious, can make two alternate generation interface slidings or peel off.Yet the measurement of the thermal expansivity of carbon nanomaterial is a difficult problem for puzzlement science and industry member always.

What thermal linear expansion coefficient was described is that unit temperature changes material elongation and the ratio of raw footage, the i.e. strain causing.The strain variation with temperature relation of directly measuring carbon nanomaterial is very difficult.Up to now, the strain variation with temperature relation of carbon nanomaterial is mainly calculated and is determined by theory, however result based on the prediction of various theoretical models differ greatly, when at room temperature carbon nanomaterial is heated, expand or shrink and there is no final conclusion.The measuring means of having developed are now mainly to measure crystallite dimension variation with temperature by X-ray diffraction, and this method precision is high, still can working sample little, finding speed is slow, instrument complex and expensive.Equally, a large amount of solvent based polymer slurries that semicon industry is used are finally all processed into the form of film, cannot prepare the block sample of regular shape, and the thermal expansivity that measure these materials also needs the more succinct assay method efficiently of exploitation.The thermal expansivity of exploitation Quick Measurement carbon nanomaterial and polymer thin-film material has important scientific meaning and application background.

Summary of the invention

Based on this, be necessary to provide a kind of assay method of thermal expansivity, to measure quickly and accurately the thermal expansivity of the materials such as carbon nanomaterial or polymkeric substance.

An assay method for thermal expansivity, comprises the steps:

Measure respectively the spectrum of testing sample under different temperatures value and obtain a plurality of the first spectral values, described different temperatures value and described a plurality of the first spectral value are carried out to linear fit, that determines described testing sample changes by unit temperature the spectrum peak amount of movement causing, counts χ _f;

Described testing sample and polymkeric substance are mixed to get to potpourri, the ultrasonic dispersion of described potpourri is obtained to compound substance;

Described compound substance is applied to different deformation, with device for measurement of strain, measure a plurality of surface strain values of described compound substance, and measure testing sample in the described compound substance spectrum under different surface strain values and obtain a plurality of the second spectral values, described a plurality of surface strain values and described a plurality of the second spectral value are carried out to linear fit, determine described testing sample by unit strain, caused, being parallel to should nyctitropic spectrum peak amount of movement, counts S ₀;

Measure testing sample in the described compound substance spectrum under different temperatures value and obtain a plurality of the 3rd spectral values, described different temperatures value and described a plurality of the 3rd spectral value are carried out to linear fit, determine the spectrum peak amount of movement being caused by unit temperature variation of the testing sample in described compound substance, count χ _c; And

According to following formula, calculate the thermal expansivity of described testing sample:

α _F=α _E-(χ _C-χ _F)/S ₀；

Wherein, described α _fthe thermal expansivity that represents described testing sample, described α _ethermal expansivity for described polymkeric substance;

Described the first spectral value, the second spectral value and the 3rd spectral value are Raman spectrum value, fluorescence emission spectrum value or infrared spectrum value.

Therein in an embodiment, describedly measure respectively the step that the spectrum of testing sample under different temperatures value obtains a plurality of the first spectral values and be specially: take step-length as 10 ℃, measure respectively described testing sample and obtain a plurality of the first spectral values to a plurality of spectrum a plurality of temperature values of the temperature of 60 ℃ of the glass transition temperatures higher than described polymkeric substance from 22 ℃.

In an embodiment, described polymkeric substance is epoxy resin, phenolics, polystyrene, PPTA, polyethylene terephthalate, polybenzimidazoles, polyetheretherketone or polyimide therein.

In an embodiment, in described potpourri, the mass ratio of described testing sample and polymkeric substance is 1:50～1:5000 therein.

In an embodiment, by the time of the ultrasonic dispersion of described potpourri, it is 0.5 hour～24 hours therein.

Therein in an embodiment, described described compound substance is applied to different deformation, the step of measuring a plurality of surface strain values of described compound substance with device for measurement of strain is specially: will after described polymer cure, cut into strip resin, and described compound substance is coated on before solidifying to the surface of described strip resin, surface at described strip resin after described composite material solidification forms coating, edge in described coating sticks foil gauge, described foil gauge is electrically connected to described device for measurement of strain, and described strip resin is applied to different deformation.

In an embodiment, the scope that described strip resin is applied to deformation is 0～0.4% therein, and step-length is 0.04%.

Therein in an embodiment, the step that the spectrum of testing sample in the described compound substance of described mensuration under different temperatures value obtains a plurality of the 3rd spectral values is specially: take step-length as 10 ℃, measure respectively testing sample in described compound substance and obtain a plurality of the 3rd spectral values to a plurality of spectrum a plurality of temperature values of the temperature of 60 ℃ of the glass transition temperatures higher than described polymkeric substance from 22 ℃.

Therein in an embodiment, the thermalexpansioncoefficientα of described polymkeric substance _emeasure as follows:

Measure respectively the spectral value that the spectrum of fibrous material under different temperatures value obtains a plurality of fibrous materials, the spectral value of described different temperatures value and described a plurality of fibrous materials is carried out to linear fit, that determines described fibrous material changes by unit temperature the spectrum peak amount of movement causing, counts χ _f1;

By cutting into strip resin after described polymer cure, described fibrous material is positioned on described strip resin, and separately takes described polymkeric substance, the described polymkeric substance separately taking is coated on described fibrous material before solidifying, after solidifying, obtain compound;

Described compound is applied to different deformation, with device for measurement of strain, measure a plurality of surface strain values of described compound, and measure the first spectral value that fibrous material in the described compound a plurality of spectral values under different surface strain values obtain the fibrous material in a plurality of compounds, the first spectral value of the fibrous material in described a plurality of surface strain values and described a plurality of compound is carried out to linear fit, determine that the unit strain of described fibrous material causes, being parallel to should nyctitropic spectrum peak amount of movement, counts S ₀₁;

Measure the second spectral value that fibrous material in the described compound spectrum under different temperatures value obtains the fibrous material in a plurality of compounds, the second spectral value of the fibrous material in described different temperatures value and described a plurality of compound is carried out to linear fit, determine the spectrum peak amount of movement being caused by unit temperature variation of the fibrous material in described compound, count χ _c1; And

According to following formula, calculate the thermal expansivity of described polymkeric substance:

α _E1=α _F1+(χ _C1-χ _F1)/S ₀₁；

Wherein, described α _e1the thermal expansivity that represents described polymkeric substance, described α _f1thermal expansivity for described fibrous material;

The first spectral value of the fibrous material in the spectral value of described a plurality of fibrous materials, a plurality of compound and the second spectral value of the fibrous material in a plurality of compound are Raman spectrum value, fluorescence emission spectrum value or infrared spectrum value.

In an embodiment, described fibrous material is alumina fibre, carbon fiber or aramid fiber therein.

The thermal expansivity of the assay method of above-mentioned thermal expansivity based on Raman spectrum, fluorescence emission spectrum or infrared spectrometry testing sample.Measure the spectrum variation with temperature of testing sample, the spectrum of the testing sample in polymeric matrix varies with temperature three parameters with temperature with the variation of strain and the spectrum of the testing sample in polymeric matrix, can calculate the thermal expansivity of testing sample.The assay method of this thermal expansivity is simple, and it is convenient to measure, and can measure comparatively quickly and accurately the thermal expansivity of testing sample.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of assay method of the thermal expansivity of an embodiment;

Fig. 2 measures the schematic diagram of Raman spectrum by Raman system;

Fig. 3 is the alumina fibre of embodiment 1 Raman spectrum when different temperatures;

Fig. 4 is the graph of a relation of Raman spectrum peak-to-peak value variation with temperature of the alumina fibre of embodiment 1;

Fig. 5 is alumina fibre in the compound of embodiment 1 Raman spectrum when different deformation;

Fig. 6 is the Raman spectral peaks peak position of the alumina fibre in the compound of embodiment 1 and the graph of a relation of strain;

Fig. 7 is alumina fibre in the compound of embodiment 1 Raman spectrum when different temperatures;

Fig. 8 is the temperature variant graph of a relation of Raman spectral peaks peak position of the alumina fibre in the compound of embodiment 1;

Fig. 9 is Raman spectral peaks (G ' peak) the variation with temperature graph of a relation of the Single Walled Carbon Nanotube of embodiment 2;

Figure 10 is Raman spectral peaks (G ' peak) frequency of the Single Walled Carbon Nanotube in the compound substance of embodiment 2 and the graph of a relation of strain;

Figure 11 is the temperature variant graph of a relation of Raman spectral peaks (G ' peak) frequency of the Single Walled Carbon Nanotube in the compound substance of embodiment 2.

Embodiment

For above-mentioned purpose of the present invention, feature and advantage can be become apparent more, below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.A lot of details have been set forth in the following description so that fully understand the present invention.But the present invention can implement to be much different from alternate manner described here, and those skilled in the art can do similar improvement without prejudice to intension of the present invention in the situation that, so the present invention is not subject to the restriction of following public concrete enforcement.

Nano material is distributed to and in polymkeric substance, makes compound substance.When the temperature of compound substance changes, because the thermal expansivity between polymkeric substance and nano material there are differences, make nano material produce deformation, two combined factors of temperature variation and deformation cause the amount of movement Δ ω of the spectrum peak of nano material _{g '}can describe with following formula:

$\mathrm{\Δ}{\mathrm{\ω}}_{G^{\′}}=\mathrm{\Δ}{\mathrm{\ω}}_{G^{\′}}^T+\mathrm{\Δ}{\mathrm{\ω}}_{G^{\′}}^S---\left(1\right).$

(1) in formula,

the spectrum peak amount of movement causing for pure temperature variation,

the spectrum peak that causes nano material generation deformation then to cause for temperature variation moves.These two parameters are determined by following two formula respectively:

$\mathrm{\&Delta;}{\mathrm{\&omega;}}_{G^{\&prime;}}^T={\mathrm{\&chi;}}_F\&times;\mathrm{\&Delta;T}---\left(2\right);$ $\mathrm{\&Delta;}{\mathrm{\&omega;}}_{G^{\&prime;}}^S={\mathrm{<figure-callout\; id="0"\; label="S"\; filenames="HDA0000445637580000022.png,HDA0000445637580000032.png"\; state="\{\{state\}\}">S</figure-callout>}}_0\&times;({\mathrm{\&alpha;}}_E-{\mathrm{\&alpha;}}_F)\&times;\mathrm{\&Delta;T}---\left(3\right).$

(2) and in (3) formula, χ _ffor the nano material spectrum peak amount of movement that unit temperature causes, α _efor the thermal expansivity of polymkeric substance, α _fthermal expansivity for nano material.S ₀for unit strain, cause, be parallel to should nyctitropic nano material spectrum peak amount of movement.

Take nano material as carbon nano-tube be example, as guided without external force, the disperse state of carbon nano-tube in polymkeric substance is random orientation, the compound substance that adopts spectroscopic system directly to measure to contain random orientation carbon nano-tube and polymkeric substance is during to the response of strain, also need to consider the actual loading situation of the carbon nano-tube that forms an angle with external force, and the difference of the carbon nano-tube of different orientation to the contribution of spectrum peak intensity, consider this 2 effects, S ₀can be described by following formula:

${\mathrm{<figure-callout\; id="0"\; label="S"\; filenames="HDA0000445637580000022.png,HDA0000445637580000032.png"\; state="\{\{state\}\}">S</figure-callout>}}_0=\frac{{\&Integral;}_0^{\mathrm{\&pi;}}{\cos }^4\&times;({\cos }^2\mathrm{\&theta;}-v{\sin }^2\mathrm{\&theta;})\mathrm{d\&theta;}}{{\&Integral;}_0^{\mathrm{\&pi;}}{\cos }^4\mathrm{\&theta;d\&theta;}}\&times;S\left(0\right)---\left(4\right).$

In formula, v is Poisson's coefficient, and θ is the angle of carbon nano-tube and external force, that S (0) causes for unit strain, to contain the compound substance of random orientation carbon nano-tube spectrum peak amount of movement.

V is that material is intrinsic.θ is intermediate variable, after integration, does not exist.

By formula (2) and (3) substitution formula (1), arrangement obtains:

△ω _G′=χ _F×△T+S ₀×(α _E-α _F)×△T （5）。

Δ ω _{g '}also can be described by following formula:

Δω _G′=χ _C×ΔT （6）。

In formula, χ _cfor carbon nanomaterial in compound substance by unit temperature, change the amount of movement of the spectrum peak cause, by measuring.

Formula (6) is updated in (5), and distortion arranges and obtains:

α _F=α _E-(χ _C-χ _F)/S ₀ （7）。

In formula:

α _fthermal expansivity for nano material;

α _ethermal expansivity for polymkeric substance.

Based on above-mentioned formula (7), obtaining α _esituation under, thermal expansivity that can be based on spectroscopic assay nano material, particularly measures carbon nanomaterial, as the thermal expansivity of carbon nano-tube, Graphene, carbon nano-fiber etc.Based on spectrum, by the thermal expansivity of above-mentioned formula (7) Quick Measurement carbon nanomaterial, solution is difficult at present measure the thermal expansivity of carbon nanomaterial or finding speed is slow and science and the industry member difficult problem of instrument complex and expensive.

Above-mentioned spectrum can be Raman spectrum, fluorescence emission spectrum or infrared spectrum.

Refer to Fig. 1, the assay method of the thermal expansivity of an embodiment, comprises the steps S110～S150.

Step S110: measure respectively the spectrum of testing sample under different temperatures value and obtain a plurality of the first spectral values, different temperatures value and a plurality of the first spectral value are carried out to linear fit, that determines testing sample changes by unit temperature the spectrum peak amount of movement causing, counts χ _f.

Testing sample can be the materials such as carbon nano-tube, Graphene, carbon nano-fiber.

The first spectral value can be Raman spectrum, fluorescence emission spectrum or infrared spectrum.

Take the first spectral value as Raman spectrum be example, please refer to Fig. 2, warm table 10 is positioned on objective table 20, and testing sample (in Fig. 2, label is 40) is placed on warm table 10 and is heated, with the laser instrument 30 of Raman system, irradiate testing sample, laser instrument 30 sends laser excitation and collects testing sample Raman spectrum under different temperatures, obtains first spectral value of testing sample under different temperatures value.

Sharp light wavelength is 240nm～800nm, is preferably 633nm.

Wherein, preferably 10 ℃ of the step-lengths of a plurality of temperature values, a plurality of temperature values are arithmetic progression, tolerance is 10 ℃.Selecting the step-length of temperature value is 10 ℃, makes the accuracy of linear relationship higher.

Preferably, the temperature by testing sample from 60 ℃ of 22 ℃ of glass transition temperatures that are heated above polymkeric substance, take 10 ℃ as step-length.For example, when the glass transition temperature of polymkeric substance is 102 ℃, sample is heated to 162 ℃ from 22 ℃, take 10 ℃ as step-length, measure the Raman spectrums under different temperatures value, measure respectively 15 Raman spectrums of testing sample at 22 ℃, 32 ℃, 42 ℃, 52 ℃, 62 ℃, 72 ℃, 82 ℃, 92 ℃, 102 ℃, 112 ℃, 122 ℃, 132 ℃, 142 ℃, 152 ℃ and 162 ℃ and obtain 15 the first spectral values.

This polymkeric substance is subsequent measurements polymkeric substance used.

Preferably, for guaranteeing the step-length of 10 ℃, when the value of glass temperature+60 ℃ and the difference of penultimate temperature value are not 10 ℃, near testing sample is heated above 60 ℃ of glass transition temperatures as test terminal temperature.

Take temperature value as horizontal ordinate, take the first spectral value as ordinate, a plurality of temperature values and corresponding a plurality of the first spectral values are carried out to linear fit, obtain the temperature of testing sample and the linear relationship of Raman spectrum, according to this linear relationship, that determines testing sample changes by unit temperature the Raman peaks amount of movement causing, counts χ _f.

Step S120: testing sample and polymkeric substance are mixed to get to potpourri, the ultrasonic dispersion of potpourri is obtained to compound substance.

Preferably, by testing sample and polymkeric substance in mass ratio 1:50～1:5000 be mixed to get potpourri.Select this mass ratio can make testing sample be well-dispersed in polymkeric substance, and polymkeric substance can not produce and disturb measurement result.

More preferably, the mass ratio of testing sample and polymkeric substance is 1:724.

Potpourri is carried out to ultrasonic dispersion so that testing sample evenly, be well-dispersed in polymkeric substance, obtain compound substance.

Preferably, by the ultrasonic dispersion of potpourri 15 hours so that testing sample disperse equably with polymkeric substance in.

Polymkeric substance is preferably epoxy resin, phenolics, polystyrene, PPTA, polyethylene terephthalate, polybenzimidazoles, polyetheretherketone or polyimide.

For measuring, need, in other embodiments, this compound substance also comprises hardening agent, so that can curing molding.

Step S130: compound substance is applied to different deformation, with device for measurement of strain, measure a plurality of surface strain values of compound substance, and measure testing sample in the compound substance spectrum under different surface strain values and obtain a plurality of the second spectral values, a plurality of surface strain values and a plurality of the second spectral value are carried out to linear fit, determine that the unit strain of testing sample causes, being parallel to should nyctitropic spectrum peak amount of movement, counts S ₀.

To after polymer cure, be cut into strip, grown * wide * height is preferably the strip resin of 70mm * 10mm * 3mm.Compound substance is coated on the surface of strip resin before solidifying, after solidifying, on the surface of strip resin, forms coating.Coating is parallel with the edge of strip resin.

The thickness of coating is preferably 20 microns.

At coating edge, stick foil gauge, two electrodes of foil gauge are drawn with device for measurement of strain and are electrically connected to electric wire, to be determined at the strain applying on strip resin.

Preferably, with four-point bending device, apply strain.

Preferably, device for measurement of strain is oscillograph.

Preferably, the scope that strip resin is applied to strain is 0～0.4%, and step-length is 0.04%.It is 0 that strain strip resin being applied starts, and is then increased to successively 0.04%, 0.08%, 0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36% and 0.40%.

Measuring respectively strain is a plurality of Raman spectrums of 0,0.04%, 0.08%, 0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36% and 0.40% correspondence, obtains the second spectral value.Be appreciated that in other embodiments, the second spectral value can be also fluorescence emission spectrum value or infrared spectrum value.

Take surface strain values as horizontal ordinate, take the second spectral value as ordinate, 11 strain values and corresponding 11 the second spectral values are carried out to linear fit, determine that the unit strain of testing sample causes, being parallel to should nyctitropic Raman peaks amount of movement, counts S ₀.

Step S140: the spectrum of the testing sample in mensuration compound substance under different temperatures value obtains a plurality of the 3rd spectral values, different temperatures value and a plurality of the 3rd spectral value are carried out to linear fit, determine testing sample in compound substance by unit temperature change cause spectrum peak amount of movement, count χ _c.

Warm table 10 is positioned on objective table 20, and compound substance is placed on warm table 10 and is heated, with the laser instrument 30 of Raman system, irradiate testing sample, laser instrument 30 sends laser excitation and collects testing sample in the compound substance spectrum under different temperatures, obtains testing sample in compound substance the 3rd spectral value under different temperatures value.

Measuring above-mentioned compound substance is to measure with the form of coating.Compound substance that can coating comprises hardening agent on the carrier of being convenient to peel off forms coating.The thickness of coating is preferably 20 microns.Carrier can tinfoil paper, aluminium foil, glass etc.

Wherein, preferably 10 ℃ of the step-lengths of a plurality of temperature values, a plurality of temperature values are arithmetic progression, tolerance is 10 ℃.

Sharp light wavelength is 240nm～800nm, is preferably 633nm.

Wherein, preferably 10 ℃ of the step-lengths of a plurality of temperature values, a plurality of temperature values are arithmetic progression, tolerance is 10 ℃.Selecting the step-length of temperature value is 10 ℃, makes the accuracy of linear relationship higher.

Preferably, the temperature by compound substance from 60 ℃ of 22 ℃ of glass transition temperatures that are heated above polymkeric substance, take 10 ℃ as step-length.

Preferably, for guaranteeing the step-length of 10 ℃, when the value of glass temperature+60 of polymkeric substance ℃ and the difference of penultimate temperature value are not 10 ℃, near compound substance is heated to the value of glass transition temperature+60 ℃ of polymkeric substance as test terminal temperature.

Take temperature value as horizontal ordinate, the 3rd spectral value of take is ordinate, a plurality of temperature values and a plurality of corresponding the 3rd spectral value are carried out to linear fit, obtain the temperature of the testing sample in compound substance and the linear relationship of Raman spectrum, according to this linear relationship, determine the Raman peaks amount of movement being caused by unit temperature variation of the testing sample in compound substance to be measured, count χ _c.

Be appreciated that in other embodiments, the 3rd spectral value can be also fluorescence emission spectrum value or infrared spectrum value.

Step S150: according to α _f=α _e-(χ _c-χ _f)/S ₀calculate the thermal expansivity of testing sample.

By above-mentioned steps, obtain χ _f, S ₀and χ _cafter, by above-mentioned formula (7): α _f=α _e-(χ _c-χ _f)/S ₀calculate, obtain the thermalexpansioncoefficientα of testing sample _f.

Wherein, α _efor the thermal expansivity of polymkeric substance, its value is known or obtained by mensuration.

Raman spectrum is a kind of spectral technique of detection molecules vibration, and it is simple, quick that it measures sample preparation, and applicable sample form is extensive, is a kind of easy, efficient detection means.Raman G ' peak frequency and its strain of carbon nanomaterial are linear, and tensile force makes its Raman peaks move to low frequency, and force of compression makes it shift to high frequency.G ' peak frequency and temperature are also linear, heat up its Raman peaks is moved to low frequency, and cooling makes it shift to high frequency.Therefore can thereby the temperature of carbon nanomaterial and strain be associated to definite its thermal expansivity by in-situ Raman spectrum.

Utilize the detection means of fluorescence emission spectrum and infrared spectrum also to there is easy, efficient advantage, can measure comparatively quickly and accurately the thermal expansivity of testing sample.

The assay method of above-mentioned thermal expansivity is the thermal expansivity based on Raman spectrum, fluorescence emission spectrum or infrared spectrometry testing sample.Raman spectrum, fluorescence emission spectrum or the infrared spectrum of by Raman system, fluorescent emission system or infrared system, measuring Raman spectrum, fluorescence emission spectrum or the infrared spectrum variation with temperature of testing sample, testing sample in polymeric matrix vary with temperature three parameters with temperature with the variation of strain and Raman spectrum, fluorescence emission spectrum or the infrared spectrum of the testing sample in polymeric matrix, can calculate the thermal expansivity of testing sample.The assay method of this thermal expansivity is simple, and it is convenient to measure, and can measure comparatively quickly and accurately the thermal expansivity of testing sample.

Use the thermal expansivity that the assay method of above-mentioned thermal expansivity not only can Measurement accuracy carbon nanomaterial, to solve science and the industry member difficult problem of the thermal expansivity of current mensuration carbon nanomaterial, can also be for measuring polymkeric substance, high-strength structure material, thermal interfacial material, for a plurality of fields such as mensuration of the silicon through hole insulating material of electric interconnection.

Preferably, the α of polymkeric substance _emeasure as follows.

Step S210: measure respectively the spectral value that the spectrum of fibrous material under different temperatures value obtains a plurality of fibrous materials, the spectral value of different temperatures value and a plurality of fibrous materials is carried out to linear fit, that determines fibrous material changes by unit temperature the spectrum peak amount of movement causing, counts χ _f1.

Fibrous material selects heat resistance at more than 120 ℃ fibrous materials, is preferably the fibrous materials such as alumina fibre, carbon fiber or aramid fiber.

Fibrous material is as internal standard compound, its thermalexpansioncoefficientα _f1for known.The spectral value of fibrous material can be Raman spectrum value, fluorescence emission spectrum value or infrared spectrum value.

Take Raman spectrum value as example, warm table 10 is positioned on objective table 20, and fibrous material is placed on warm table 10 and is heated, with the laser instrument 30 of Raman system, irradiate testing sample, laser instrument 30 sends laser excitation and collects fibrous material Raman spectrum under different temperatures, obtain the spectral value of fibrous material under different temperatures value, obtain the spectral value of a plurality of fibrous materials.

Sharp light wavelength is 240nm～800nm, is preferably 633nm.

Temperature by fibrous material from 60 ℃ of 22 ℃ of glass transition temperatures that are heated above polymkeric substance, measures the Raman spectrum at a plurality of temperature.Wherein, preferably 10 ℃ of the step-lengths of a plurality of temperature values, a plurality of temperature values are arithmetic progression, tolerance is 10 ℃.Preferably, for guaranteeing the step-length of 10 ℃, when the value of glass temperature+60 ℃ and the difference of penultimate temperature value are not 10 ℃, near fibrous material is heated to the value of its glass transition temperature+60 ℃ as test terminal temperature.

Take temperature value as horizontal ordinate, the spectral value of fibrous material of take is ordinate, the spectral value of a plurality of temperature values and a plurality of corresponding fibrous materials is carried out to linear fit, obtain the temperature of fibrous material and the linear relationship of Raman spectrum, according to this linear relationship, that determines fibrous material changes by unit temperature the Raman peaks amount of movement causing, counts χ _f1.

Step S220: by cutting into strip resin after polymer cure, fibrous material is positioned on strip resin, and separately takes polymkeric substance, the polymkeric substance separately taking is coated on fibrous material before solidifying, obtain compound after solidifying.

The step that obtains compound is specially: take a certain amount of polymkeric substance, will after this polymer cure, be cut into strip resin.Fibrous material is lain on strip resin, make it be parallel to strip resin edge, then, separately take a certain amount of polymkeric substance, the polymkeric substance that this is separately taken is coated on the surface of fibrous material before solidifying, and the surface at fibrous material after solidifying forms coating, obtains compound.

The length of strip resin * wide * height is preferably 70mm * 10mm * 3mm.The thickness of coating is preferably 20 microns.

Step S230: compound is applied to different deformation, with device for measurement of strain, measure a plurality of surface strain values of compound, and measure the first spectral value that fibrous material in the compound a plurality of spectral values under different surface strain values obtain the fibrous material in a plurality of compounds, the first spectral value in fibrous material in a plurality of surface strain values and a plurality of compound is carried out to linear fit, determine fibrous material by unit strain, caused, being parallel to should nyctitropic spectrum peak amount of movement, counts S ₀₁.

Edge in coating sticks foil gauge, and two electrodes of foil gauge are drawn with device for measurement of strain and are electrically connected to electric wire, to be determined at the strain applying on strip resin.

Preferably, with four-point bending device, apply strain.Device for measurement of strain is oscillograph.

Preferably, the scope that strip resin is applied to strain is 0～0.4%, and step-length is 0.04%.It is 0 that strain strip resin and coating being applied starts, and is then increased to successively 0.04%, 0.08%, 0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36% and 0.40%.

Measuring respectively strain is a plurality of Raman spectrums of 0,0.04%, 0.08%, 0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36% and 0.40% correspondence, obtains the second Raman spectrum value.

Take surface strain values as horizontal ordinate, the first spectral value of the fibrous material of take in compound is ordinate, the first spectral value of the fibrous material in 11 strain values and corresponding compound is carried out to linear fit, determine fibrous material by unit strain, caused, being parallel to should nyctitropic Raman peaks amount of movement, counts S ₀₁.

Be appreciated that in other embodiments, the first spectral value of the fibrous material in compound can be fluorescence emission spectrum or infrared spectrum.

Step S240: the spectrum of the fibrous material in mensuration compound under different temperatures value obtains the second spectral value of the fibrous material in a plurality of compounds, the second spectral value of the fibrous material in different temperatures value and a plurality of compound is carried out to linear fit, determine the spectrum peak amount of movement being caused by unit temperature variation of the fibrous material in compound to be measured, count χ _c1.

Sharp light wavelength is 240nm～800nm, is preferably 633nm.

The second spectral value of the fibrous material of take in compound is example, and compound, from 22 ℃ of temperature that are heated above 60 ℃ of glass transition temperature of polymer, is measured to the Raman spectrum at a plurality of temperature.Wherein, preferably 10 ℃ of the step-lengths of a plurality of temperature values, a plurality of temperature values are arithmetic progression, tolerance is 10 ℃.Selecting the step-length of temperature value is 10 ℃, makes the accuracy of linear relationship higher.

Preferably, the temperature by compound from 60 ℃ of 22 ℃ of glass transition temperatures that are heated above polymkeric substance, take 10 ℃ as step-length.

Preferably, for guaranteeing the step-length of 10 ℃, when the value of glass temperature+60 ℃ and the difference of penultimate temperature value are not 10 ℃, near compound is heated to the temperature of glass transition temperature+60 ℃ of polymkeric substance as test terminal temperature.

Take temperature value as horizontal ordinate, the second spectral value of the fibrous material of take in compound is ordinate, the second spectral value of the fibrous material in a plurality of temperature values and a plurality of corresponding compound is carried out to linear fit, obtain the temperature of the fibrous material in compound and the linear relationship of Raman spectrum, according to this linear relationship, determine the Raman peaks amount of movement being caused by unit temperature variation of the fibrous material in compound, count χ _c1.

Be appreciated that in other embodiments, the second spectral value of the fibrous material in compound can be fluorescence emission spectrum or infrared spectrum.

Step S250: according to α _e1=α _f1+ (χ _c1-χ _f1)/S ₀₁calculate the thermal expansivity of polymkeric substance.

By above-mentioned steps, obtain χ _f1, S ₀₁and χ _c1after, by formula: α _e1=α _f1+ (χ _c1-χ _f1)/S ₀₁calculate, obtain the thermalexpansioncoefficientα of polymkeric substance _e1.

Wherein, α _e1thermal expansivity for polymkeric substance.α _f1for the thermal expansivity of fibrous material, its value is known.

Said method can be measured the thermalexpansioncoefficientα of polymkeric substance exactly _e1, by said method, measure the thermalexpansioncoefficientα of polymkeric substance _e1after, then adopt the step of above-mentioned steps S110～S140 to measure, by α _e1as α _ebring in above-mentioned formula (7), measure the thermalexpansioncoefficientα that obtains the testing samples such as carbon nanomaterial _f.By adopting fibrous material further to improve the accuracy of the MEASURING THE THERMAL EXPANSION COEFFICIENT of the other materials such as carbon nanomaterial as the method for the thermal expansivity of internal standard compound mensuration polymkeric substance.

By specific embodiment, further set forth below.

Embodiment 1

Measure the thermal expansivity of bisphenol A type epoxy resin

1, single alumina fibre is placed in to warm table, warm table is placed on optical microscope objective table, alumina fibre is heated, between 22 ℃ to 142 ℃, take 10 ℃ as step-length heating, adopt Renishaw2000 Raman system to measure the Raman spectrum under different temperatures, with 633nm laser excitation, collect the Raman spectrum of alumina fibre under different temperatures, obtain 13 the first Raman spectrum values.Wherein, the R1 peak of alumina fibre under 295K and 415K as shown in Figure 3.Using 22 ℃, 32 ℃, 42 ℃, 52 ℃, 62 ℃, 72 ℃, 82 ℃, 92 ℃, 102 ℃, 112 ℃, 122 ℃, 132 ℃ and 142 ℃ of these 13 temperature values as horizontal ordinate, using corresponding 13 the first Raman spectrum values as ordinate, 13 temperature values and 13 corresponding the first Raman spectrum values are carried out to linear fit, as shown in Figure 4, linear relationship is ω to linear graph _r1=1354+0.154T.According to this linear relationship, determine χ _f1, numerical value is listed in table 1;

2, by bisphenol A type epoxy resin and hardening agent in mass ratio 100:38 be mixed to get the potpourri of bisphenol A type epoxy resin and hardening agent, the potpourri of a part of bisphenol A type epoxy resin and hardening agent is at room temperature solidified 24 hours, then at 100 ℃, solidify 4 hours, after solidifying, be cut into the strip resin of 70mm * 10mm * 3mm.Single alumina fibre is lain on strip resin, make it be parallel to strip resin edge, the potpourri of another part bisphenol A type epoxy resin and hardening agent is coated on alumina fibre before solidifying, under room temperature, solidify 24 hours, then solidify 4 hours at 100 ℃, form and be coated on the lip-deep coating of alumina fibre, obtain compound to be measured, wherein, the thickness of coating is 20 microns;

3, at 3mm place, the side of strip resin and alumina fibre, paste foil gauge, foil gauge two electrodes are drawn with wire.Compound to be measured is inserted to four-point bending device, place it on optical microscope objective table, strip resin and coating are applied to deformation, answering variable step is 0.04%, by oscilloscope measurement surface strain.Adopt Renishaw2000 Raman system, with 633nm laser excitation, collect alumina fibre at differently strained lower Raman spectrum, obtain a plurality of the second Raman spectrum values.The R1 peak of compound to be measured and strain stress relation be (the peak figure of 0% strain and 0.4% strain) as shown in Figure 5.Using strain 0%, 0.04%, 0.08%, 0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36% and 0.40% as horizontal ordinate, a plurality of second Raman spectrum values of correspondence of take are carried out linear fit as ordinate, as shown in Figure 6, linear relationship is ω to linear graph _r1=1405-12 * 10 ^-2ε.According to this linear relationship, determine S ₀₁, numerical value is listed in table 1.

4, compound to be measured is placed in to warm table, between 22 ℃ to 152 ℃, take 10 ℃ as step-length heating, adopts Renishaw2000 Raman system, with 633nm laser excitation, collect fiber fluorescent emission spectrum under different temperatures, obtain a plurality of the 3rd Raman spectrum values.The R1 peak of sample varies with temperature relation as shown in Figure 7.There is glass transition at about 102 ℃ and enter elastomeric state in bisphenol A type epoxy resin, the stress transmission efficiency from resin to alumina fibre reduces, therefore at definite χ _ctime the data point only chosen between 22 ℃～102 ℃ make linear fit.Using 22 ℃, 32 ℃, 42 ℃, 52 ℃, 62 ℃, 72 ℃, 82 ℃, 92 ℃ and 102 ℃ respectively as horizontal ordinate, using relative a plurality of the 3rd Raman spectrum values as ordinate, carry out linear fit, linear relationship chart as shown in Figure 8.Linear relationship is ω _r1=1381+0.079T, determines χ according to this linear relationship _c1, numerical value is listed in table 1.

The thermal expansivity of alumina fibre is 9 * 10 ^-6k ^-1, i.e. α _f1=9 * 10 ^-6k ^-1.By α _f1and the χ that obtains of said determination _f1, S ₀₁and χ _c1substitution formula α _e1=α _f1+ (χ _c1-χ _f1)/S ₀₁in, calculate the thermalexpansioncoefficientα of bisphenol A type epoxy resin _e1, numerical value is listed in table 1.

The data that the thermal expansivity of the bisphenol A type epoxy resin being recorded by said method and Huntsman company product technology handbook provide are coincide, and illustrate that the assay method of the above-mentioned thermal expansivity based on Raman spectrum is very reliable.

Embodiment 2

Measure the thermal expansivity of carbon nano-tube

1, Single Walled Carbon Nanotube is placed in to warm table, warm table is placed on optical microscope objective table, carbon nano-tube is heated, between 22 ℃ to 162 ℃, take 10 ℃ as step-length heating, adopt Renishaw2000 Raman system, with 633nm laser excitation, collect the Raman spectrum of carbon nano-tube under different temperatures, obtain 15 the first spectral values.Using 22 ℃, 32 ℃, 42 ℃, 52 ℃, 62 ℃, 72 ℃, 82 ℃, 92 ℃, 102 ℃, 112 ℃, 122 ℃, 132 ℃, 142 ℃, 152 ℃ and 162 ℃ of these 15 temperature values as horizontal ordinate, using corresponding 15 the first spectral values as ordinate, 15 temperature values and 15 corresponding the first spectral values are carried out to linear fit, as shown in Figure 9, linear relationship is ω to linear graph _{g '}=2643-0.029T.According to this linear relationship, determine χ _f, numerical value is listed in table 1;

2,10mg Single Walled Carbon Nanotube is joined in 7.24g bisphenol A type epoxy resin, ultrasonic dispersion 15 hours, obtains the potpourri of resin and carbon nano-tube.To this potpourri, add 2.76g hardening agent, mix and obtain compound substance, (bisphenol A type epoxy resin and hardening agent in mass ratio 100:38 mix this compound substance to be coated in before solidifying to the strip resin of 70mm * 10mm * 3mm, after solidifying, cutting obtains, preparation method is with embodiment 1) on, after solidifying, on the surface of strip resin, form coating, coating thickness is 20 microns.Curing method is at room temperature to solidify 24 hours, then solidifies 4 hours at 100 ℃;

3, at 3mm place, the side of coating, paste foil gauge, the electrode of foil gauge is drawn with wire.Compound substance to be measured is inserted to self-control four-point bending device and is placed on optical microscope objective table, strip resin and coating are applied to deformation.By oscilloscope measurement surface strain.Adopt Renishaw2000 Raman system, with 633nm laser excitation, collect the Raman spectrum of Single Walled Carbon Nanotube under different surfaces strain, obtain a plurality of the second spectral values, using surface strain 0%, 0.04%, 0.08%, 0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36% and 0.40% as horizontal ordinate, a plurality of second spectral values of correspondence of take carry out linear fit as ordinate, and linear graph as shown in figure 10.Linear relationship is ω _{g '}=2635-14.6 ε.According to this linear relationship, determine S ₀, by ω _{g '}=2635-14.6 * 10 ^-2ε determines S (0)=14.6, S ₀=1.3 * S (0), numerical value is listed in table 1;

4, painting is placed in warm table, between 22 ℃ to 162 ℃, take 10 ℃ as step-length heating, adopt Renishaw2000 Raman system, with 633nm laser excitation, collect compound substance to be measured Raman spectrum under different temperatures, using 22 ℃, 32 ℃, 42 ℃, 52 ℃, 62 ℃, 72 ℃, 82 ℃, 92 ℃ and 102 ℃ respectively as horizontal ordinate, using corresponding a plurality of the 3rd spectral values as ordinate, carry out linear fit, linear relationship chart as shown in figure 11.Linear relationship is ω _{g '}=2674-0.129T, determines χ according to this linear relationship _c, numerical value is listed in table 1.

The thermal expansivity of Single Walled Carbon Nanotube can be by formula α _f=α _e-(χ _c-χ _f)/S ₀determine, wherein, α _efor the thermal expansivity of bisphenol A type epoxy resin, be 7.2 * 10 ^-5k ^-1, by embodiment 1, measure and obtain, calculate the thermalexpansioncoefficientα of Single Walled Carbon Nanotube _flist in table 1.

Table 1

The above embodiment has only expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims (10)

1. an assay method for thermal expansivity, comprises the steps:

Measure respectively the spectrum of testing sample under different temperatures value and obtain a plurality of the first spectral values, described different temperatures value and described a plurality of the first spectral value are carried out to linear fit, that determines described testing sample changes by unit temperature the spectrum peak amount of movement causing, counts χ _f;

Described testing sample and polymkeric substance are mixed to get to potpourri, the ultrasonic dispersion of described potpourri is obtained to compound substance;

Described compound substance is applied to different deformation, with device for measurement of strain, measure a plurality of surface strain values of described compound substance, and measure testing sample in the described compound substance spectrum under different surface strain values and obtain a plurality of the second spectral values, described a plurality of surface strain values and described a plurality of the second spectral value are carried out to linear fit, determine described testing sample by unit strain, caused, being parallel to should nyctitropic spectrum peak amount of movement, counts S ₀;

Measure testing sample in the described compound substance spectrum under different temperatures value and obtain a plurality of the 3rd spectral values, described different temperatures value and described a plurality of the 3rd spectral value are carried out to linear fit, determine the spectrum peak amount of movement being caused by unit temperature variation of the testing sample in described compound substance, count χ _c; And

According to following formula, calculate the thermal expansivity of described testing sample:

α _F=α _E-(χ _C-χ _F)/S ₀；

Wherein, described α _fthe thermal expansivity that represents described testing sample, described α _ethermal expansivity for described polymkeric substance;

Described the first spectral value, the second spectral value and the 3rd spectral value are Raman spectrum value, fluorescence emission spectrum value or infrared spectrum value.

2. the assay method of thermal expansivity according to claim 1, it is characterized in that, describedly measure respectively the step that the spectrum of testing sample under different temperatures value obtains a plurality of the first spectral values and be specially: take step-length as 10 ℃, measure respectively described testing sample and obtain a plurality of the first spectral values to a plurality of spectrum a plurality of temperature values of the temperature of 60 ℃ of the glass transition temperatures higher than described polymkeric substance from 22 ℃.

3. the assay method of thermal expansivity according to claim 1, it is characterized in that, described polymkeric substance is epoxy resin, phenolics, polystyrene, PPTA, polyethylene terephthalate, polybenzimidazoles, polyetheretherketone or polyimide.

4. according to the assay method of the thermal expansivity described in claim 1 or 3, it is characterized in that, in described potpourri, the mass ratio of described testing sample and polymkeric substance is 1:50～1:5000.

5. the assay method of thermal expansivity according to claim 1, is characterized in that, by the time of the ultrasonic dispersion of described potpourri, is 0.5 hour～24 hours.

6. the assay method of thermal expansivity according to claim 1, it is characterized in that, described described compound substance is applied to different deformation, the step of measuring a plurality of surface strain values of described compound substance with device for measurement of strain is specially: will after described polymer cure, cut into strip resin, and described compound substance is coated on before solidifying to the surface of described strip resin, surface at described strip resin after described composite material solidification forms coating, edge in described coating sticks foil gauge, described foil gauge is electrically connected to described device for measurement of strain, described strip resin is applied to different deformation.

7. the assay method of thermal expansivity according to claim 6, is characterized in that, the scope that described strip resin is applied to deformation is 0～0.4%, and step-length is 0.04%.

8. the assay method of thermal expansivity according to claim 1, it is characterized in that, the step that the spectrum of testing sample in the described compound substance of described mensuration under different temperatures value obtains a plurality of the 3rd spectral values is specially: take step-length as 10 ℃, measure respectively testing sample in described compound substance and obtain a plurality of the 3rd spectral values to a plurality of spectrum a plurality of temperature values of the temperature of 60 ℃ of the glass transition temperatures higher than described polymkeric substance from 22 ℃.

9. the assay method of thermal expansivity according to claim 1, is characterized in that, the thermalexpansioncoefficientα of described polymkeric substance _emeasure as follows:

Measure respectively the spectral value that the spectrum of fibrous material under different temperatures value obtains a plurality of fibrous materials, the spectral value of described different temperatures value and described a plurality of fibrous materials is carried out to linear fit, that determines described fibrous material changes by unit temperature the spectrum peak amount of movement causing, counts χ _f1;

By cutting into strip resin after described polymer cure, described fibrous material is positioned on described strip resin, and separately takes described polymkeric substance, the described polymkeric substance separately taking is coated on described fibrous material before solidifying, after solidifying, obtain compound;

Described compound is applied to different deformation, with device for measurement of strain, measure a plurality of surface strain values of described compound, and measure the first spectral value that fibrous material in the described compound a plurality of spectral values under different surface strain values obtain the fibrous material in a plurality of compounds, the first spectral value of the fibrous material in described a plurality of surface strain values and described a plurality of compound is carried out to linear fit, determine that the unit strain of described fibrous material causes, being parallel to should nyctitropic spectrum peak amount of movement, counts S ₀₁;

Measure the second spectral value that fibrous material in the described compound spectrum under different temperatures value obtains the fibrous material in a plurality of compounds, the second spectral value of the fibrous material in described different temperatures value and described a plurality of compound is carried out to linear fit, determine the spectrum peak amount of movement being caused by unit temperature variation of the fibrous material in described compound, count χ _c1; And

According to following formula, calculate the thermal expansivity of described polymkeric substance:

α _E1=α _F1+(χ _C1-χ _F1)/S ₀₁；

Wherein, described α _e1the thermal expansivity that represents described polymkeric substance, described α _f1thermal expansivity for described fibrous material;

The first spectral value of the fibrous material in the spectral value of described a plurality of fibrous materials, a plurality of compound and the second spectral value of the fibrous material in a plurality of compound are Raman spectrum value, fluorescence emission spectrum value or infrared spectrum value.

10. the assay method of thermal expansivity according to claim 9, is characterized in that, described fibrous material is alumina fibre, carbon fiber or aramid fiber.

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