CZ293755B6 - Method for determining physical and mechanical properties of semicrystalline polymers - Google Patents

Abstract

The present invention makes it possible to determine physical and mechanical properties (such as elastic deformation modulus, strength, ductility, tenacity, hardness, luster, bloom, density, gas un vapor permeability) of semicrystalline polymers, the glass transition temperature (Tg) of which is less than temperature of physical and mechanical property measurements, for example polypropylene, polyethylene, propylene and ethylene copolymers, polyvinylidene fluoride, polyoxymethylene, polyamide 11, plasticized polyvinyl chloride. The measurement method consists in that after finish of heat preparation of test bodies, there is conducted a series of measurements of physical and mechanical properties and ratio of solid (immovable, rigid) phase in semicrystalline polymer is determined simultaneously by employing e1H-NMR pulse method. A correlation of individual physical and mechanical properties with ration of the steady phase is constructed, whereby the property value extrapolated to 100-percentage ratio of the solid phase corresponds to a limiting physical and mechanical property of the semicrystalline polymer. In addition to said limiting values, there are determined by extrapolation or interpolation physical and mechanical properties, corresponding to arbitrary ratio of the solid phase being determined by the e1H-NMR pulse method.

Description

Method for determination of physical-mechanical properties of semi-crystalline polymers

Technical field

The invention relates to a method of physicochemical properties including the determination of their limit values for semicrystalline polymers whose glass transition temperature of the amorphous fraction (Tg) is lower than the measurement temperature of physicochemical properties such as polypropylene, polyethylene, propylene-ethylene copolymers , plasticized polyvinyl chloride, and the like.

BACKGROUND OF THE INVENTION

Semi-crystalline polymers, such as polypropylene and its copolymers, polyethylene, and the like, are increasingly used as construction materials in engineering practice. Due to the low cost of health, easy recyclability, good workability and satisfying physico-mechanical properties, new applications are still found, the problem with these semi-crystalline polymers is the strong dependence of physico-mechanical properties on the time elapsed since the last heat treatment. In practice, the physical-mechanical properties of these materials, or the utility properties of the products made therefrom, have changed since the measurement of the physical-mechanical properties on the fresh product until the end use of the product.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for determining the physico-mechanical properties of semi-crystalline polymers that are independent of the aging (conditioning) period and can therefore be considered as material characteristics.

Currently, the physical-mechanical properties of polymers are evaluated by standard standardized methods specified in different countries, eg CSN, ISO, ASTM, etc. These methods allow to determine the physical-mechanical properties after prescribed conditioning, eg temperature +23 ° C, relative humidity 50% , 2 to 7 days after preparation of the test specimens. The physical-mechanical properties thus measured depend significantly on the conditioning time and, as a rule, do not provide any indication of the actual physical-mechanical properties that the materials achieve on the final products during their use, i.e. after conditioning usually lasting months to years. The time dependence of the physical-mechanical properties of semi-crystalline polymers has been described in detail, for example, by L.C.E. Struik in "Physical Aging in Amorphous Polymers and Other Materials," (Elsevier, Amsterdam 1978). these time dependencies of physico-mechanical properties are not generally linearizable and it is not realistic to obtain the so-called limit physico-mechanical properties by extrapolation to the “infinitely long” conditioning period. This is due to the non-linearity of the physical-mechanical dependence on time, the non-linearity of the logarithm (or any simple function) of time, and, moreover, the validity of the empirical rule that forbid extrapolate the results of time dependence measurements by more than one order of time.

Interpretation of the temporal dependence of the physical-mechanical properties of semicrystalline polymers has been addressed by a number of authors, eg S. Kapur and C.E. Rogers: J. Polyn. Sci .: Polym, Phys. Ed., 10, 2107 (1972) investigated isotactic polypropylene, L. Guadagno, C. Fontanella, V. Vittoria, and P. Longo: J. Polym. Sci .: Part B: Polym. Physics, 37, 173 (1999) investigated syndiotactic polypropylene. R. Verma, H. Marand and B. Hsiao: Macromolecules 29, 7767 (1996), by measuring X-ray scattering on poly (ether-ether ketone) samples, attributed the time dependence of the physical-mechanical properties of the semi-crystalline polymer to the so-called secondary crystallization. of the initially liquid polymer in the spaces between the lamellae within the spherolite to the solid polymer. The crystallinity of semi-crystalline polymers is measured by several different traditional methods (X-ray, density, calorimetric, etc.). How to use these

Methods for determining the so-called limit values of the physical-mechanical properties of semi-crystalline polymers are not known.

Currently, some specialized companies (Bruker Optik GmbH, Germany, Oxford Instruments, 5 Idustrial Analysis Group, GB, Resonance Instruments, GB) are making devices that measure the solid (rigid) or fixed phase fraction in semi-crystalline polymers by pulse 1 H-NMR. The solid phase is defined by a short, so-called spin-spin relaxation time T ₂ <10 ps, see, e.g., Fujimoto K., Nishi T., Kado R., Polymer J. 3, 448 (1972). Conversely, the liquid phase is defined by a long spin-spin relaxation time, typically T ₂ > 10 ps. to Measurement is generally indirect, relative, ie requires calibration using a series of reference samples.

The method of direct, absolute measurement of the solids fraction of semi-crystalline polymers by this method is not known. In this context, it should be noted that the solid (immovable) fraction determined by the pulse 'NMR method is not the same as the crystalline fraction (crystallinity) determined, for example, by X-ray diffraction, DSC or density.

It has now been found that the above-mentioned task of determining the physical-mechanical properties of semi-crystalline polymers that are independent of the aging (conditioning) period (and thus may be considered as material characteristics) can be solved by applying the ¹ H-NMR method.

SUMMARY OF THE INVENTION

The subject of the invention is at certain time intervals the repeated measurement of the physical-mechanical properties of semi-crystalline polymers and simultaneously measuring the solid-state fraction by the pulse 25 Ή-NMR method, correlation between the measured physico-mechanical property and the solid-phase fraction and interpolation or extrapolation to any value preferably to 100% solids.

The semicrystalline polymers whose physicochemical properties can be evaluated by the method 30 of the present invention are those whose glass transition temperature (Tg) is lower than the physicochemical measurement temperature. If the samples are conditioned and the physical-mechanical properties are evaluated at a normal temperature of +23 ° C or +28 ° C, for example, polypropylene, polyethylene, copolymers of propylene and ethylene, polyoxymethylene, polyvinylidene fluoride, polyamide 11, plasticized polyvinyl chloride and the like. In the case of other conditioning temperatures and measurements of physical-mechanical properties, the process can be extended to other polymers.

It has been found that by the pulse ¹ H-NMR method, the proportion of solid (rigid, immovable) and liquid (movable) phases of semicrystalline polymers can be determined under the same conditions (i.e., at the same conditioning time, at the same temperature) as and correlate the physical-mechanical properties of the solid-state polymers. These generally linear correlations (dependencies) of the physical-mechanical properties of solid-phase semicrystalline polymers are characteristic of a particular semicrystalline polymer and express the parameters that a given material can achieve during any aging period (conditioning). Physical-mechanical property values extrapolated to 100% solids of the semicrystalline polymer phase are also characteristic of the particular semicrystalline polymer.

For optimum results, care should be taken to prepare test specimens and condition them. Advantageously, test bodies (eg according to ISO 3167, type A) injected in a standard manner as described in, for example, ISO 1873-2: 1997 (defines PP injection conditions and types and conditions) may be used to measure physico-mechanical properties and solids fraction 50. tests) into a mold according to ISO 294-1: 1996 (defines type, mold design, injection parameters and their tolerances). However, the method according to the invention is not limited to said standard bodies. Any other test specimens can be used, eg extruded bodies, foils, granules, 5S fibers, parts of products (eg tubes), etc. The condition is that as soon as possible after the last

Temperature process (usually extrusion, injection molding, blow molding, thermoforming) to cool the test specimen as quickly as possible to the conditioning conditions (temperature, pressure, humidity) and to measure the physical-mechanical properties and solids fraction at certain intervals .

Advantageously, conditions for conditioning may be selected as described in international standards for measuring the physical-mechanical properties of polymers, e.g., temperature +23 ° C, rel. a humidity of 50%, or a temperature of +28 ° C, see for example ISO 291: 1977. If the application of the polymer occurs under conditions other than these standardized conditions, it is possible to condition the bodies and, if necessary, measure the physical-mechanical properties; select the otherwise defined conditions from the solid phase of the semicrystalline polymer; this applies, for example, to pipes for conducting hot media.

The time intervals for measuring the physical-mechanical properties and the solid phase fraction are selected from the time of cooling of the test specimens to the measurement temperature over a period of days, months to years, preferably a constant increase in logarithm of time. With lower demands on accuracy and knowledge of the behavior of a particular material, measurements at two times elapsed since heat preparation of the test specimens are sufficient.

The determination of physical-mechanical properties can be carried out according to the applicable standard standards. The physical-mechanical properties whose values can be determined in this way are e.g.

(a) density of polymeric material (eg according to ISO 1183: 1987);

(b) tensile, bending, creeping elastic modulus (eg ISO 527: 1966, ISO 178: 1993),

(c) yield stress and fracture stress, deformation of the body at yield stress and fracture (eg according to ISO 527: 1966),

(d) Charpy impact and / or notch toughness (eg ISO 179: 1993) or Izod (eg ISO 180: 1993);

(e) polymer hardness as determined by the indentation of the ball (eg according to ISO 2039-1), or the Rockwell hardness (eg according to ISO 2039-2: 1989), or the Shore A or Shore D hardness (according to ISO 868: 1985);

f) permeability of gases and vapors,

g) Turbidity of the polymer (e.g. according to ASTM D 1003-92).

The measurement of the solid phase fraction in a semi-crystalline polymer consists of measuring the so-called free induction decay (FID) signal under the same conditions and on the same test specimens on which the physical-mechanical properties are evaluated. By mathematically processing the measured FID signal, the solid phase fraction of the semi-crystalline polymer is calculated. The measurement of the solid phase fraction in the semicrystalline polymer can be performed on any device that enables pulse ¹ H-NMR measurement of magnetization. These are, for example, commercially available devices for evaluating the structure of polymers, e.g.

(a) Bruker minispec mq20, Bruker minispec NMS 120, manufactured by Bruker Optik GmbH (Germany);

(b) QP20 + and Magneflow from Oxford Instruments, Industrial Analysis Group (GB);

(c) the MARAN Ultra from Resonance Instruments (GB).

The correlation of the physical-mechanical properties of the semi-crystalline polymers with the solids fraction determined by the pulse Ή-NMR method is ideally linear. In the case of high solids polymers (such as isotactic polypropylene), a significant part of the solid phase increase (eg from 94 to 99%) and the corresponding physical-mechanical properties can be measured in real-time conditioning, so extrapolating to 100% solids the phase is

Methodologically justified. Both the correlation of the properties with the solids fraction and the corresponding limit properties obtained by extrapolating the dependence on the 100% solids fraction can be considered as material characteristics of the semi-crystalline polymers.

In the case of low solids polymers (such as low density polyethylene, polyoxymethylene), real-time conditioning (1 hour - 1 year) can measure a portion of the solid phase increase that is quite far from the 100% limit at its maximum (e.g., from 70 to 85%) and the corresponding physico-mechanical properties, so extrapolation to 100% solids is methodologically less justified. In the case of these materials, however, the correlation of the physical-mechanical properties in the solid-state fraction, which can be regarded as a material characteristic of the semi-crystalline polymers, is of importance.

Overview of pictures

Giant. 1: Dependence of mechanical properties on the solid phase fraction of injection molded bodies of commercial isotactic polypropylene Mosten 58.412. Conditioning temperature and measurement of body properties at 23 ° C. An illustration of the method of extrapolating the values to 100% solids of the sample (see Example 1, Table 1).

Giant. 2: Dependence of density on solid phase fraction of injection molded bodies prepared from several commercial and laboratory produced isotactic polypropylenes. Condition temperature of body properties measurement at 23 ° C. An illustration of the method of extrapolating the values to 100% solids of the sample (see Example 2, Table 2).

DETAILED DESCRIPTION OF THE INVENTION

The following examples illustrate the invention.

Example 1

Test specimens according to ISO 3167, type A were made from injection molding machine Mattenfeld (A) BA 750 / CD from polypropylene granules Mosten 58.412 (manufactured by Chemopetrol, Czech Republic). The injection process was according to ENISO 1873-2: 1998 and ČSN EN ISO 294—1: 1999 under the following conditions: cylinder temperature 200 to 230 ° C, mold temperature 40 ° C, injection pressure approx. 50 MPa, injection rate 29%, pressure approx. 50 MPa, pressure time 40 s, cooling time in The test specimens were cooled to +23 ° C after injection and adjusted to the shape necessary for the evaluation of the physical-mechanical properties.

To measure the time dependence of changes in the solids fraction of the material, the samples were immediately adjusted to a beam size of 40 to 50 mm and placed in a cuvette for measuring FID signals using the pulse 'NMR method.

Determination of density by flotation and pycnometric method

The measurement is performed according to the standard ČSN 64 0111: 1993. The granules are tested without prior mechanical treatment. Their selection is limited to those which do not contain bubbles. Other products are cut into bodies, which must be smooth, free of cracks, unevenness and bubbles. Undesirable deformations should be avoided when cutting the bodies. Five specimens were taken for measurement. A mixture of distilled water and fine ethanol for density measurements was used for density determination. If the liquid poorly wetted the sample, a drop of wetting agent was added.

-4GB 293755 B6

Determination of solid phase fraction by pulse ´-NMR method

The measurement was performed on a Bruker minispec mq20 pulse ¹ H-NMR spectrometer. The determination is based on the measurement of the time dependence of the FID signal strength of protons * H in a strong magnetic field (0.47 Tesla, 20 MHz). The central parts of the injection bodies, modified to a length of 40 to 50 mm, were inserted as test bodies and were placed on the bottom of a glass cuvette with a clearance of 18 mm and a height of 180 mm. With the Haake Extreme Water Thermostat, the temperature of the spectrometer probe was set to 23 ° C with an accuracy of 0.1 ° C. The magnet temperature was 40 ° C with a maximum variation of 0.005 ° C. The FID signal was measured between 7 and 106 ps over a total of 250 timeline points. 25 scans were performed within one measurement. The FID signal was processed to determine the proportion of solid and liquid phases. The FID signal is an exponential function of time. The measured FID waveform was described by an equation composed of two exponential functions, the first one being the solid part and the second one the liquid part.

y = a. exp (-t / T _2a ) + b. exp (-t / T _2b ) where a is a constant proportional to the solid phase fraction, T _2a is a spin-spin relaxation time characterizing the solid phase, b is a constant proportional to the liquid fraction phase, T _2b is the spin-spin relaxation time characterizing the liquid phase and t is the time for which the signal subsides. Individual parameters (a, b, T _2a and T _2b ) were calculated in Excel by applying the "Solver" procedure, interleaving experimentally measured FID signal values with two exponential functions with minimization of deviations by the least squares method. The fraction of solid phase a was calculated as the fraction of constants characterizing the fraction of solid (a) and liquid (b) phase, extrapolated and zero time:

a = -100 a = [%] a + b

Measurement sequence and conditioning conditions

The first measurement of the solids content occurred after approx. 30 minutes from the removal of the test specimens from the mold, when it was possible to observe that the specimens were leaving at a temperature of 23 + 0.1 ° C. the cooling rate could be increased by cooling with a stream of air. Further measurements were taken after 2.4, 7 and 24 hours, after 3.7.21 days, after two months and half a year after the preparation of the bodies. The first measurement of the physical-mechanical properties occurred 1 hour after removal from the mold. Other measurement intervals are shown in Tab. 1.

The following parameters were measured in a standard way according to the relevant standards, see Tab. 1 and 1.

Tab. 1: Properties of injection molded bodies made of polypropylene Mosten 58.412

Duration of the concession Proportion of solid phase Density Tension at yield strength Deformation at yield strength Flexural modulus Pulse @ 1 H-NMR CSN 640111: 1993 ISO 527: 1966 ISO 527: 1966 ISO 178: 1993 t [h] <x [%] P [kg / ™ ³ ] σ, [MPa] E,[%] E [MPa] 1 95.9 32.7 9.0 1359 5 96.7 902.8 33.3 8.3 1426 48 97.4 903.7 34.6 7.6 1592 96 97.7 904.2 34.0 7.6 1607 840 97.9 904.9 35.7 7.1 1723 2350 98.1 905.1 35.0 7.0 1651 5928 98.2 905.5 35.8 6.7 1797 Limit ¹ ' 100.0 908.2 37.8 5.2 2050

^1} Limit values extrapolated to the proportion of solid phase to 100% according to the procedure shown in FIG. 1.

-5GB 293755 B6

Example 2

From isotactic polypropylene granules Mosten 58.412 and Mosten 56.915 (manufactured by Chemopetrol, Czech Republic), Moplen HOXP 817 (manufactured by Basell Polyolefins, Italy), Metocene 5 50249 (manufactured by BASF AG, Germany) and four laboratory-prepared and granulated samples of isotactic polypropylene B1193 ( LI. = 98.9%, IT ₂ and _N = 7 g / Lomin) G1874 (II = 99.4%, IT2in = 1.1 g / 10 min), G1901 (LI. = 99.1%; IT _21N = 0.5 g / 10 min) and G1919 (II = 98.2%, ΓΓ ₂ ιν ⁼ 0.6 g / 10 min) injection molded bodies according to Example 1 were prepared (II is the polypropylene isotacticity index, determined according to ISO 9113: 1986, ΓΓ ₂ ι _N is the melt flow index o determined at 21 N load according to ISO 1133: 1997). The bodies prepared in this way were cooled to +23 ° C and conditioned at this temperature for a long time. The following physical-mechanical properties were evaluated on these bodies at +23 ° C by standard methods:

-densities (according to ČSN 64 0111: 1993) and solid phase fractions (pulse ´ Η-NMR method and Bruker minispec 15 pulse spectrometer mq20) after the conditioning time see tab. 2,

- mechanical properties (stress and elongation at yield strength according to ISO 527: 1966, tensile modulus according to ISO 527: 1966, flexural modulus according to ISO 178: 1993, Shore D hardness according to ISO 868: 1985, notch toughness of Charpy at +23 ° C according to ISO 179: 1993) and solid phase fractions after conditioning for 7 days and about 200 days, see Tab. 3.

The results are shown in the following Table. 2 and tab. 3. The density dependences on the solid phase fraction were correlated in Fig. 2.

Tab. 2: Densities and solids fractions of injection molded bodies of evaluated polypropylene samples. Measured parameters: part t, solid phase fraction a, density p

Sample Property Measured values Limit ¹ ' Mosten 58.412 t [h] 5 48 96 840 2350 5928 - - <x [%] 96.7 97.4 97.7 97.9 98.1 98.2 - 100.0 p [kg / m ³ ] 902.8 903.7 904.2 904.9 905.1 905.5 - 908.6 Mosten 56: 915 t [h] 3 24 72 144 336 1032 1920 - <x [%] 96.93 97.51 97.86 98.02 98.25 98.45 98.49 100.0 p [kg / m ³ ] 904.2 904.8 905.1 905.4 905.7 906.0 906.0 907.8 Moplen HOXP 817 t [h] 3 24 72 192 528 1080 4944 - <x [%] 95.99 96.62 97.05 97.27 97.51 97.60 98.7 100.0 P [kg / m ³ ] 904.5 905.0 905.7 906.1 906.1 906.6 906.8 909.2 Metocene 50249 t [h] 3 24 48 336 504 960 4584 - and[%] 95.85 96.82 97.04 97.52 97.67 97.88 98.31 100.0 p [kg / m ³ ] 900.6 901.4 901.5 902.2 902.3 902.7 903.1 904.5 B1193 t [h] 3 72 240 408 - - - - <x [%] 96.76 97.86 98.05 98.24 - - - 100.0 p [kg / m ³ ] 904.0 905.0 905.2 905.5 - - - 907.2 G1874 t [h] 3 72 240 408 - - - - <* [%] 96.86 97.84 97.95 98.19 - - - 100.0 P [kg / m ³ ] 903.0 904.2 904.7 904.9 - - - 907.3 G1901 tm 3 24 48 173 365 557 1128 - α [%] 95.66 96.44 96.68 97.16 97.43 97.44 97.53 100.0 p [kg / m ³ ] 903.5 904.4 904.9 905.1 905.3 905.5 905.7 908.1 G1919 t [h] 3 24 72 312 480 - - - and[%] 94.82 95.79 96.12 96.60 96.70 - - 100.0 Pkg / m ³ ] 904.1 904.7 905.2 905.9 906.1 - - 909.3

Limit values linearly extrapolated to 100% solids fraction according to the procedure shown in Figure 2.

-6GB 293755 B6

Tab. 3: Physical-mechanical properties and proportions of solid phase injected bodies of evaluated polypropylene samples

Sample Cond. Proportion of solid phase Stretch between the slip Deformation at yield strength Tensile modulus Flexural modulus Hardness 15 p Notch, downy. Charpy Pulse iu_ NMR ISO 527: 1966 ISO 527: 1966 ISO 527 ISO 178: 1993 ISO 868: 1985 ISO 179 h % MPa % MPa MPa Shote D kJ / m ¹ Mosten 58.412 7 97.61 34.8 7.4 1649 1630 66.7 5.0 247 98.17 35.8 6.7 1797 1676 64.6 4.6 Limit ¹ ' 100.00 39.1 4.4 2281 1826 57.7 3.2 Mosten 56.915 7 97.22 33.2 7.8 1340 1320 66.2 2.7 234 98.66 36.0 6.7 1760 1492 64.8 2.2 Limit. ¹ ' 100.00 38.6 5.7 2151 1652 63.5 1.7 Moplen HOXP 817 7 97.18 35.6 7.5 1510 1550 69.2 4.4 206 98.07 38.5 6.8 1883 1734 67.7 3.4 Limit ¹ ' 100.00 44.8 5.3 2692 2133 64.4 1,2 Metocene 50249 7 97.34 32.4 7.9 1260 1250 68.8 2.4 191 98.31 34.3 6.8 1622 1450 66.7 2.3 Limit ¹ ' 100.00 37.6 4.9 2253 1798 63.0 2.1

limit values linearly extrapolated to 100% solids fraction according to the procedure shown in Figure 2.

Example 3

From polyethylene granules LDPE Bralen VA 20-60 (manufacturer as Slovnaft, Slovakia), HDPE Liten VA 20-60 (manufacturer as Chemopetrol, Czech Republic) and LLDPEExceed ML4518FC (manufacturer ExxonMobil ChemicalSAS, France) and polyoxymethylene Hostaform C13021FS / SH (manufacturer Hoechst (Germany), injection molded bodies according to Example 1 were prepared. These bodies were cooled to + 23 ° C and conditioned at this temperature for a long time. The following physical-mechanical properties were evaluated on these bodies at +23 ° C by standard methods:

-densities (according to ČSN 64 0111: 1993) and solid phase fractions (by pulse * H-NMR method on a Bruker minispec mq20 pulse spectrometer) after the conditioning period given in the following Tab. 4,

- mechanical properties, such as hardness according to ISO 868: 1985, modulus of elasticity in the three-point bending test according to ISO 178: 1993, stress and relative yield stress, maximum elongation and stress at maximum and stress and relative strain at break according to ISO 527: 1966 , notched Charpy toughness at +23 ° C according to ISO 179: 1993 and solid phase fractions (pulse ¹ H-NMR on a Bruker minispec mq20 pulse spectrometer) after conditioning for 1 and 5 h, 1, 7.21 and 63 days.

The results are shown in Tables 4 to 7, where the standard deviation of the respective measurement is.

Tab. 4: Correlation of LDPE Bralen VA 20-60 properties with solids fraction measured on injection molded bodies.

-8EN 293755 B6

Tab. 5: Correlation of HDPE Litem VA 20-60 with solids content measured on injection molded bodies.

-9EN 293755 B6

Tab. 6: Correlation of LLDPEExceed ML4518FC with solids content measured on injection molded bodies.

Time Fixed share phase Density σ Hardness σ Bending module. σ Rel. prot. naMK σ Voltage per MC σ h % kg / m ’ “Shore D MPa % NPa 1 76.28 47.1 0.1 183.3 2,0 17.8 0.7 8.48 0.03 5 76.41 46.7 0.3 197.1 4.8 18.9 8.46 0.03 24 76.58 47.3 0.4 197.7 2,0 17.6 0.4 8.71 0.02 48 76.57 915.9 0.0001 72 76.55 47.5 0.4 209.7 6.0 17.1 0.4 8.71 0.07 168 76.71 47.5 0.4 215.6 4.6 17.6 1.3 8.81 0.04 216 76.74 916.5 0.0001 504 76.92 45.2 0.7 222.0 1.5 16.6 0.6 9.03 0.04 528 76.94 917.6 0.0001 1512 77.06 918.6 0.0001 46.6 1.1 231.7 λθ 16.0 0.4 9,30 0.03

Tab. 7: Correlation of POMHostaform C13021FS / SH properties with solids fraction measured on injection molded bodies.

Time Fixed share phase Density σ Hardness σ Bending module. σ Rel. prot. naMK σ Voltage per MC σ Vrubová houž. Charpy σ h % kg / m ³ ° Shore D MPa % MPa kJ / nt 1 83.16 76.6 0.4 2282 29 9.6 0.3 63.1 0.4 5 83.14 76.9 0.6 2377 23 8.9 0.4 63.7 0.1 24 83.19 1405.6 0.0001 77.5 0.7 2479 35 8.8 02 / 64.2 0.1 62 0.4 72 83.31 77.0 0.2 2532 9 7.8 ο, ι 64.7 0.2 5.5 1.0 168 83.42 77.3 0.4 2628 35 7.8 0.2 65.0 0.2 5.2 0.9 192 83.44 1406.9 0.0002 504 83.53 76.0 0.9 2688 23 7.4 0.3 65.9 0.02 4.4 0.7 528 83.55 1409.0 0.0001 1512 83.64 1409.8 0.0003 78.0 0.7 2777 31 6.8 0.04 66.5 0.06 4.6 1.0

Industrial applicability

The method for evaluating the physical-mechanical properties of semicrystalline polymers of the present invention provides essential and novel information about the behavior of semicrystalline polymers at both real and limit times of use.

The limiting physical-mechanical properties of the semi-crystalline polymers as well as the dependence of the physical-mechanical properties on the solid phase fraction of the polymer obtained according to the present invention can be considered as material characteristics of these polymers. These characteristics provide information about their properties over the entire period of their use. They can be used for optimum design of products to optimize their production technology and to determine the limits of the permissible stresses in their use.

It is advantageous to use both extrapolation of physicochemical properties to low solids fractions, ie for short times after production of the product, which can be useful especially for optimization of technological steps, and extrapolations to high solids fractions, ie very long and no longer specified the times after manufacture of the product from which the appropriate limit values for the physico-mechanical quantities required for the application of the strength and durability criteria for the product can be obtained.

In this way, conventional physical-mechanical properties can be evaluated, e.g., modulus of elasticity, strength, toughness, ductility, hardness, gloss, haze, density, gas and vapor permeability. Thus, the aforementioned physico-mechanical properties can be determined at times when, for various reasons

They may dampen their direct measurement of the moses (eg due to time consuming methods, measurement costs, etc.).

PATENT CLAIMS

Claims (4)

PATENT CLAIMS A method for determining the physico-mechanical properties of semicrystalline polymers as a function of the solids fraction of the polymer, characterized in that the solids fraction of the solids is determined by a pulse-NMR-NMR method over a long period of time. the long-term time dependence of the selected physico-mechanical properties shall also be determined in parallel after the test specimens have been made into the mold required for testing and the necessary conditioning time has elapsed, whereupon the correlation dependencies are determined by correlating the corresponding physico-mechanical values with by interpolation, it determines the physical-mechanical properties corresponding to a particular proportion of solid phase. Method according to claim 1, characterized in that the so-called limit values of selected physical-mechanical properties are determined from the correlation dependencies by extrapolation to the limit value of 100% solid phase fraction. Method according to claim 1, characterized in that the so-called extrapolated values of selected physico-mechanical properties are determined from the correlation dependencies by extrapolation to experimentally determined solid phase fraction values for short times corresponding to the state immediately after production and the temperature of the product with the environment. for such short aging times of the product, where their direct measurement by measurement is not technically possible. Method according to claim 1, characterized in that they are polymers whose glass transition temperature (Tg) is lower than the temperature measurement of the properties, preferably polypropylene, polyethylene, copolymers of propylene and ethylene, polyoxymethylene, polyvinylidene fluoride, polyamide 11, plasticized polyvinyl chloride.