CN105628812A - Method for testing surface free energy of polymer packing - Google Patents

Abstract

The invention discloses a method for testing surface free energy of polymer packing. The method comprises the following steps that 1, a packing sample to be tested is dried and then filled into a packed column; 2, the packed column obtained in the step 1 is aged; 3, parameters are set, a gas chromatograph testing system is started, mixed liquor of nonpolar probe molecules and polar probe molecules are injected, and the retention time of the nonpolar probe molecules and the retention time of the polar probe molecules are obtained through testing; 4, calculation is performed. The testing method is suitable for multiple kinds of inorganic packing, and the tested result is accurate, stable and reliable.

Description

A kind of method of test polymer filling surface free energy

Technical field

The present invention relates to inorganic filler surface free energy technical field of measurement and test, specifically, it relates to a kind of method of test polymer filling surface free energy.

Background technology

Filler is one of main raw material of polymer industry, the performance of the many excellences of polymkeric substance can be given, such as making non-self reinforced rubber have practical value, the filler for rubber industry mainly contains carbon black, white carbon black, calcium carbonate, kaolin, polynite, potter's clay, mica powder, talcum powder etc.

The surface free energy of filler affects the adsorptivity of itself and polymkeric substance, associativity and dispersion, processing characteristics and end properties for polymeric system play most important effect, by affecting the reinforcement of rubber with the physics chemical action of polymkeric substance, then physical and mechanical properties and the dynamic properties having influence on polymeric articles, the surface free energy of filler can regard the surfactivity of filler as herein.

But at present not the surfactivity of mineral filler and organic filler being carried out careful research, also existence operation is loaded down with trivial details and the shortcoming of poor repeatability for the method for conventional test surfaces free energy, and the data obtained are single, can not the character of many-sided reflection filler. The particularly carbon black of gasification poor for light transmission, difficult, the surfactivity of test carbon black is particularly difficult. The surfactivity of filler can be reflected by surface free energy, this technology is exactly the test adsorption free energy of filler, dispersion free energy and polar component to analyze the adsorptivity of filler, polar/non-polar degree, reunion degree, dispersion in the polymer and the consistency with various polymkeric substance, and then judges filler use properties in the polymer.

Summary of the invention

For above-mentioned problems of the prior art, the present invention provides a kind of method of test polymer filling surface free energy, and the method for the present invention is simple to operate, and repeatability is good, and result is accurate, is applicable to various fillers.

For achieving the above object, the present invention provides following technical scheme:

A method for test polymer filling surface free energy, comprises the following steps:

(1), after packing samples to be measured being dried, packed column is loaded;

(2) packed column step (1) obtained is aging;

(3) parameters, opens the test macro of gas chromatograph, injects nonpolar probe molecule mixed solution and polarity probes molecule, and test obtains the retention time of nonpolar probe molecule and the retention time of polarity probes molecule;

(4) calculate:

Seek net retention volume:

Vn=j²��D(t_r-t_m)

Wherein: j is correction factor, D is flow after post, t_rFor retention time, t_mFor the dead time;

Correction factor j is tried to achieve by following formula:

$j=\frac{{(p_i/p_0)}^2-1}{{(p_i/p_0)}^3-1}\×\frac{3}{2}$

Wherein, p_iRefer to chromatographic column intake pressure, i.e. pressure before post, p₀Refer to column outlet pressure, namely press after post;

Seek adsorption free energy

$-\mathrm{\Δ}G=RTln\frac{{\mathrm{CV}}_N}{Sg}$

-�� G refers to the negative value of adsorption free energy, and R refers to gas law constant; T refers to packed column temperature; C=299; S refers to total specific surface area of filler; G refers to the quality of filler in packed column, with-�� the G of the nonpolar probe molecule injected, carbonatoms is drawn Trendline, obtains slope, obtains the adsorption free energy change-�� G that single methylene radical causes_CH2;

Seek dispersion free energy

$r_s^d={\[\frac{-{\mathrm{\ΔG}}_{{\mathrm{CH}}_2}}{2N_A{\mathrm{\α}}_{{\mathrm{CH}}_2}}\]}^2\frac{1}{r_{{\mathrm{CH}}_2}}$

Refer to dispersion free energy, N_AFor Avogadro constant; ��_CH2Refer to single CH₂Area (0.06nm²); r_CH2Represent only by CH₂The surface energy of the solid matter that group is formed take polyethylene as standard, and value is 35mJ/m²;

Seek the polar portion-�� �� G of polarity probes molecular adsorption free energy, by-�� the G of described nonpolar probe molecule, its molecular cross sectional area is done linear equation, then the molecular cross sectional area of polarity probes molecule is substituted into equation, obtain the nonpolar part of polar molecule adsorption free energy, subtract its nonpolar part with the total adsorption free energy of polar molecule again, namely obtain-�� �� G;

Seek the polar portion of filling surface free energy

$I_{sp}=\frac{-\mathrm{\Δ}\mathrm{\Δ}G}{N_A{\mathrm{\α}}_P}$

��_pFor probe molecule occupies the surface-area of filler;

Filling surface free energy r is made up of polar portion and nonpolar part,

R=r_s ^d+I^sp

For the nonpolar part surface free energy of filler, also referred to as dispersion free energy; I^spFor the polar portion surface free energy of filler;

Described filler comprises carbon black, white carbon black, calcium carbonate, polynite, kaolin, mica powder, potter's clay, talcum powder.

Further, in step (3), described nonpolar probe molecule mixed solution comprises Skellysolve A, normal hexane and normal heptane, and volume ratio is 1:1:1.

Further, in step (2), described aging temperature is 130-150 DEG C.

Further, in step (3), during parameters, if filler is carbon black or white carbon black, probe temperature is set to 130 DEG C; If filler is calcium carbonate, polynite, kaolin, mica powder, potter's clay or talcum powder, probe temperature is set to 100 DEG C.

Further, in step (4), to r_CH2Following formula is utilized to correct:

$r_{{\mathrm{CH}}_2}=36.8-0.058T$

Further, in step (3), nonpolar probe molecule mixed solution injects 3 times in packed column, and the retention time of nonpolar probe molecule gets the mean value of 3 times.

The useful effect of the present invention is as follows:

1, reinject in packed column after 3 kinds of nonpolar probe molecules being mixed, it does not interfere with each other mutually between each probe molecule, avoid the operating time error between different nonpolar probe molecule, make the variance of the linear equations formula made bring up to more than 0.999;

2, adopt formula unlike the prior art when the present invention calculates, make whole computation process be suitable for mineral filler, and result more accurately and is stablized;

3, the present invention gives the parameters such as the aging temperature of mineral filler, the probe molecule kind of use, probe temperature again, breaks through traditional view, makes test result more accurate.

Embodiment

In order to make those skilled in the art understand the technical scheme of the present invention better; the technical scheme of the present invention is carried out clear, complete description below; based on the embodiment in the application; other roughly the same embodiment that those of ordinary skill in the art obtain under the prerequisite not making creative work, all should belong to the scope of the application's protection.

Embodiment one:

A method for test polymer filling surface free energy, comprises the following steps:

(1) granulated filler to be measured selects 60-80 order, powdery filler directly uses, packing samples to be measured is put into baking oven drying 1 hour under 125 DEG C of conditions, after dry, load packed column, packed column selects stainless steel, first the packed column of sky is carried out purifying treatment before filling, then takes appropriate filler and insert packed column; For granulated filler, especially carbon black, particle is uneven, if directly loading pillar, degree of compactness can be caused uneven, increases test error.

(2) packed column step (1) obtained is aging, and aging needs carries out in a nitrogen environment, control temperature 130 DEG C, aging 10 hours; Usual mineral filler selects the temperature higher than 180 DEG C to carry out aging, but the present inventor finds, in the nitrogen environment of mineral filler more than 180 DEG C long-time aging time, specific surface area can become big, cause measuring result that deviation occurs, the present invention select 130-150 DEG C aging, the impact of the surface properties of mineral filler is little, and aging object can be reached.

(3) parameters, opens gas chromatograph test macro, injects nonpolar probe molecule mixed solution and polarity probes molecule, and test obtains the retention time of nonpolar probe molecule and the retention time of polarity probes molecule; Wherein, described nonpolar probe molecule mixed solution comprises Skellysolve A, normal hexane and normal heptane, and volume ratio is 1:1:1, and polarity probes molecule comprises methyl alcohol, toluene, ethyl acetate and acetonitrile, if filler is carbon black or white carbon black, probe temperature is set to 130 DEG C; If filler is calcium carbonate, polynite, kaolin, mica powder, potter's clay or talcum powder, probe temperature is set to 100 DEG C. For anti-phase gas-chromatography, usually Skellysolve A, normal hexane, normal heptane and octane is adopted, but the present inventor finds octane, and polarity parameter is bigger, the error produced when doing linear dependence with first three normal alkane is bigger, causing net result relatively large deviation occur, therefore the present invention only selects Skellysolve A, normal hexane and normal heptane as nonpolar probe molecule. Reinject in packed column after 3 kinds of nonpolar probe molecules are mixed, it does not interfere with each other mutually between each probe molecule, avoid the operating time error between different nonpolar probe molecule, make the variance of the linear equations formula made bring up to more than 0.999. In addition, the present inventor finds, for a lot of mineral filler, when probe temperature reaches 150 DEG C, the surface of mineral filler changes, specific surface area becomes big, cause test result that error occurs, and for carbon black or white carbon black, probe temperature is set to 130 DEG C, for mineral fillers such as calcium carbonate, polynite, kaolin, mica powder, potter's clay, talcum powder, probe temperature is set to 100 DEG C, test can be made normally to carry out, inorganic filler surface can be avoided again to change, ensure the accuracy of result.

Nonpolar probe molecule mixed solution injects 3 times in packed column, and the retention time of nonpolar probe molecule gets the mean value of 3 times, to ensure that result is more accurate.

(4) calculate:

Seek net retention volume:

Vn=j²��D(t_r-t_m)

Wherein: j is correction factor, D is flow after post, t_rFor retention time, t_mFor the dead time;

Correction factor j is tried to achieve by following formula:

$j=\frac{{(p_i/p_0)}^2-1}{{(p_i/p_0)}^3-1}\×\frac{3}{2}$

Wherein, p_iRefer to chromatographic column intake pressure, i.e. pressure before post, p₀Refer to column outlet pressure, namely press after post;

Seek adsorption free energy

$-\mathrm{\Δ}G=RTln\frac{{\mathrm{CV}}_N}{Sg}$

-�� G refers to the negative value of adsorption free energy, and R refers to gas law constant; T refers to packed column temperature; C=299; S refers to total specific surface area of filler; G refers to the quality of filler in packed column, with-�� the G of the nonpolar probe molecule injected, carbonatoms is drawn Trendline, obtains slope, obtains the adsorption free energy change-�� G that single methylene radical causes_CH2;

Seek dispersion free energy

$r_s^d={\[\frac{-{\mathrm{\ΔG}}_{{\mathrm{CH}}_2}}{2N_A{\mathrm{\α}}_{{\mathrm{CH}}_2}}\]}^2\frac{1}{r_{{\mathrm{CH}}_2}}$

Refer to dispersion free energy, N_AFor Avogadro constant; ��_CH2Refer to single CH₂Area (0.06nm²); r_CH2Represent only by CH₂The surface energy of the solid matter that group is formed, to r_CH2Following formula is utilized to correct:

$r_{{\mathrm{CH}}_2}=36.8-0.058T$

The usual r of prior art_CH2Directly adopt definite value 35mJ/m², along with the change that probe temperature is arranged, there will be certain deviation, affect the accuracy of test result, therefore this parameter has been corrected by the present invention, makes test result more accurate, and result stability is better.

Seek the polar portion-�� �� G of polarity probes molecular adsorption free energy, by-�� the G of described nonpolar probe molecule, its molecular cross sectional area is done linear equation, then the molecular cross sectional area of polarity probes molecule is substituted into equation, obtain the nonpolar part of polar molecule adsorption free energy, subtract its nonpolar part with the total adsorption free energy of polar molecule again, namely obtain-�� �� G;

Seek the polar portion of filling surface free energy

$I_{sp}=\frac{-\mathrm{\Δ}\mathrm{\Δ}G}{N_A{\mathrm{\α}}_P}$

��_pFor probe molecule occupies the surface-area of filler;

Filling surface free energy r is made up of polar portion and nonpolar part,

R=r_s ^d+I^sp

For the nonpolar part surface free energy of filler, also referred to as dispersion free energy; I^spFor the polar portion surface free energy of filler;

Described filler comprises carbon black, white carbon black, calcium carbonate, polynite, kaolin, mica powder, potter's clay, talcum powder.

Embodiment two:

The part that the present embodiment is identical with embodiment one repeats no more, the difference is that, aging temperature is 140 DEG C.

Embodiment three:

The part that the present embodiment is identical with embodiment one repeats no more, the difference is that, aging temperature is 150 DEG C.

Simultaneous test:

Get carbon black and polynite appropriate, the testing method (test group) of the present invention and the testing method (control group) of Chinese patent application publication No. CN104165960A announcement is adopted to be measured by its surface free energy respectively, the measurement of test group and test group respectively carries out 3 times, calculating the variance of 3 results, result is such as table 1 and table 2:

The test of table 1 carbon blacksurface free energy

The test of table 2 polynite surface free energy

As can be seen from table 1 and table 2, between 3 results that the testing method of employing control group records, deviation is bigger, unstable result, owing to the standard surface free energy of sample can not be learnt, therefore the stability of result can reflect the accuracy of test result from an aspect, it may also be useful between 3 results that the testing method of the present invention records, deviation is very little, result good stability, therefore can speculating, the filling surface free energy result that the present invention records is more accurate.

In addition, it is to be understood that, although this specification sheets is described according to enforcement mode, but not each enforcement mode only comprises an independent technical scheme, this kind of narrating mode of specification sheets is only for clarity sake, those skilled in the art should by specification sheets integrally, and the technical scheme in each embodiment through appropriately combined, can also form other enforcement modes that it will be appreciated by those skilled in the art that.

Claims (6)

1. the test polymer method of filling surface free energy, it is characterised in that, comprise the following steps:

(1), after packing samples to be measured being dried, packed column is loaded;

(2) packed column step (1) obtained is aging;

(3) parameters, opens the test macro of gas chromatograph, injects nonpolar probe molecule mixed solution and polarity probes molecule, and test obtains the retention time of nonpolar probe molecule and the retention time of polarity probes molecule;

(4) calculate:

Seek net retention volume:

Vn=j²��D(t_r-t_m)

Wherein: j is correction factor, D is flow after post, t_rFor retention time, t_mFor the dead time;

Correction factor j is tried to achieve by following formula:

$j=\frac{{(p_i/p_0)}^2-1}{{(p_i/p_0)}^3-1}\×\frac{3}{2}$

Wherein, p_iRefer to chromatographic column intake pressure, i.e. pressure before post, p₀Refer to column outlet pressure, namely press after post;

Seek adsorption free energy

$-\mathrm{\Δ}G=RTln\frac{{\mathrm{CV}}_N}{Sg}$

-�� G refers to the negative value of adsorption free energy, and R refers to gas law constant; T refers to packed column temperature; C=299; S refers to total specific surface area of filler; G refers to the quality of filler in packed column, with-�� the G of the nonpolar probe molecule injected, carbonatoms is drawn Trendline, obtains slope, obtains the adsorption free energy change-�� G that single methylene radical causes_CH2;

Seek dispersion free energy

$r_s^d={\[\frac{-{\mathrm{\ΔG}}_{{\mathrm{CH}}_2}}{2N_A{\mathrm{\α}}_{{\mathrm{CH}}_2}}\]}^2\frac{1}{r_{{\mathrm{CH}}_2}}$

Refer to dispersion free energy, N_AFor Avogadro constant; ��_CH2Refer to single CH₂Area (0.06nm²); r_CH2Represent only by CH₂The surface energy of the solid matter that group is formed take polyethylene as standard, and value is 35mJ/m²;

Seek the polar portion-�� �� G of polarity probes molecular adsorption free energy, by-�� the G of described nonpolar probe molecule, its molecular cross sectional area is done linear equation, then the molecular cross sectional area of polarity probes molecule is substituted into equation, obtain the nonpolar part of polar molecule adsorption free energy, subtract its nonpolar part with the total adsorption free energy of polar molecule again, namely obtain-�� �� G;

Seek the polar portion of filling surface free energy

$I_{sp}=\frac{-\mathrm{\Δ}\mathrm{\Δ}G}{N_A{\mathrm{\α}}_P}$

��^pFor probe molecule occupies the surface-area of filler;

Filling surface free energy r is made up of polar portion and nonpolar part,

R=r_s ^d+I^sp

For the nonpolar part surface free energy of filler, also referred to as dispersion free energy; I^spFor the polar portion surface free energy of filler;

Described filler comprises carbon black, white carbon black, calcium carbonate, polynite, kaolin, mica powder, potter's clay, talcum powder.

2. the method for test polymer filling surface free energy according to claim 1, it is characterised in that, in step (3), described nonpolar probe molecule mixed solution comprises Skellysolve A, normal hexane and normal heptane, and volume ratio is 1:1:1.

3. the method for test polymer filling surface free energy according to claim 1, it is characterised in that, in step (2), described aging temperature is 130-150 DEG C.

4. the method for test polymer filling surface free energy according to claim 1, it is characterised in that, in step (3), during parameters, if filler is carbon black or white carbon black, probe temperature is set to 130 DEG C; If filler is calcium carbonate, polynite, kaolin, mica powder, potter's clay or talcum powder, probe temperature is set to 100 DEG C.

5. the method for test polymer filling surface free energy according to claim 1, it is characterised in that, in step (4), to r_CH2Following formula is utilized to correct:

$r_{{\mathrm{CH}}_2}=36.8-0.058T$

6. the method for test polymer filling surface free energy according to claim 1, it is characterized in that, in step (3), nonpolar probe molecule mixed solution injects 3 times in packed column, and the retention time of nonpolar probe molecule gets the mean value of 3 times.