elastomery termoplastyczne w technologii druku 3D. 32 nr 4. TOM 20 październik – grudzień Thermoplastic elastomer filaments and their application in. Przykłady zastosowań · Technologia aplikacji. Wiedza. Wydarzenia · Elastomery termoplastyczne · Spawanie laserowe · Najczęściej występujące problemy. Jedyny autoryzowany dystrybutor materiałów firmy PTS w Polsce: Elastomery termoplastyczne, tworzywa inżynieryjne, wtrysk wielokomponentowy, substytucja .
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December 7th Reviewed: July 13th Published: The influence of the number of carbons separating the terephtalate groups, as well as the effect of meta- or para- positions of the ester groups in the benzene ring of other blocks, on the synthesis, properties and structure of these elastomers have been evaluated.
The influence of chemical compositions of ester block on the functional properties and on the values of phase transition temperatures of the products have been determined.
The thermal properties and the phase separation of obtained systems were defined by differential scanning calorimetry DSCdynamic mechanical thermal analysis DMTAwide-angle x-ray diffraction WAXS and other standard physical methods.
The mechanical and elastic properties of obtained polymers were evaluated. A growing demand for polymeric materials in the packaging, sport, automotive, and medicine industries stimulates the search for innovative materials with thermal and mechanical properties individually tailored for a given field.
Depending on the application, these materials have to be characterized, among others, by their resistance to chemical, mechanical, or biological factors.
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These requirements may be successfully satisfied by the thermoplastic multiblock elastomer TPE. They combine the end-use elastomfry properties of vulcanized rubbers with the easy processing of thermoplastic [1—5]. The elasgomery of TPEs are influenced by an appropriate phase structure and its teromplastyczne reproducibility in the heating-cooling cycle, functional qualities large, reversible termoplastyczn and the processing properties possibility of multiple melting and solidifications.
TPEs are considered as polymeric materials, in which, as a result of the phase separation, at least two phases soft and hard are distinguished, which must be thermodynamically immiscible to prevent the interpenetration. Hence, these are plastics possessing at least the two values of the physical transition temperatures, i. These two temperatures determine the points at which the particular elastomer goes through transitions in its physical properties [ 6 ].
There are three distinct regions:. Some of multiblock copolymers that have a heterophase internal structure are epastomery as the group of thermoplastic elastomers. Their macromolecule must contain two types of chain segments: These blocks differ considerably in their physical and chemical properties.
The soft blocks, which are capable of forming a soft-phase matrix, provides the elastomeric character, susceptibility to hydrolysis, and behavior of copolymer at low temperatures; while the hard segments determine processability, mechanical properties, hardness, and high temperature resistance. Hard segments are able to form intermolecular association with other hard blocks and these blocks form the domains of hard phase and are immersed in a soft-phase matrix.
To classify the block elastomers to TPEs, their internal structure must comply with strict conditions. The soft phase should exhibit a relatively small elastic modulus, relatively elatomery glass transition temperature, and a lower density.
Moreover, these blocks should ensure weak intermolecular interactions and a large capability for motion and rotation of short sequences of chains.
elastomery – Translation into English – examples Polish | Reverso Context
The hard phase must possess a relatively large elasticity modulus, high glass transition temperature or melting point, and high density. The segments termoplastycczne build this phase must exhibit a tendency to aggregate with the same kind of segments.
The intermolecular interactions of rigid blocks affect the stabilization of the phase structure of the whole polymeric system. The hard segments must have a larger cohesive energy than the flexible segments and termopllastyczne, a higher thermodynamic potential. The potential difference is a force that induces and stabilizes a heterophase structure [13—17]. The block copolymer will exhibit characteristics of a good elastomer if it complies with five inseparable conditions:.
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Such macromolecules construction allows a close proximity of the hard blocks and intermolecular interactions. The TPE properties are a result of the combination of the individual features of the respective blocks, hence a change of their chemical structure or their relative mass fraction, enables a modification of the macromolecule properties in the desired directions [18—25].
In the present chapter, the synthesis of multiblock thermoplastic elastomers and the relationship between the chemical structure of soft block and the properties in connection with the phase structure of terpolymers are described.
The following terpolymers were selected for this research study:. The following termoplqstyczne were used: The lactam and the elasto,ery acid are the substrates prepared in our laboratory: Synthesis was carried out in a cylindrical shape with conical bottom 6-dm 3 autoclave made of stainless steel.
The ratio of height to reactor diameter is h: The regulators are controlled by Fe-constantan thermocouples and Pt thermoresistors. A suitable amount of laurolactam and sebacic acid, which was a stabilizator of molecular weight of the obtained oligoamides, termoplastycne placed in the reactor. A small dose of water and phosphoric acid was added elastokery simplify the initiation of the reaction.
Before the synthesis, the autoclave was purged three times with nitrogen at the pressure of 0. After that, the reaction mixture was kept in the reactor under a pressure of 0. A pressure would not exceed 1. The pressure was controlled by the removal of water vapor that contained a small amount of amide di- and trimers. This pressure stage of the reaction lasted 5 h. Termoplzstyczne, the pressure was reduced during 0. The pressureless stage polycondensation was carried out for 5 h under a flow of nitrogen.
After the reaction was completed, the obtained oligoamide was extruded by compressed nitrogen into a tube with water that was vigorously stirring with bubbling air. To extract the residual by-products and unreacted lactam the finished product was rinsed three times with boiling water and then with distilled water. Synthesis of block terpolymers proceeded in the two stages. The second stage of the process comprises the specific condensation polymerization of mixed intermediates obtained in the first stage of synthesis.
The course and parameters of synthesis is presented in Figure 1. Preparation of terpolymers relies on the replacement in the poly multi-methylene terephthalate macromolecule xGTa certain part of fragments originated from the terephthalic acid by the dicarboxylic oligoamide block, which was derived from glycol by the oligoetherdiol or alifatic block Figure 2. This determines a relatively small fraction of the xGT sequence in the soft phase, large degrees of separation of both soft and hard phase and comparable fraction of the respective blocks in the interphase.
The series differ in a chemical structure of the ester block. The molar ratio and weight ratios of reagent used for the synthesis were presented in Table 1. The difference between the molecular weight values, calculated from the amounts of the carboxylic groups and the assumed theoretical values do not exceed 2.
Usage of sebacic acid as the molecular weight stabilizer leads to dicarboxylic oligoamids. Obtained oligoamids had coherent with assumed molecular weight values, didn’t contain amid groups, and may be used as hard block in various types of thermoplastic multiblock elastomers. The number of carbons x separating the terephthalate groups in the ester block of TPEs influences all their properties, which were presented in Table 3.
The properties of terpolymer elastomers TPE with variable chemical structure of ester block. The ability to swell depends on the polarity of the solvent and the chemical structure of the polymer macromolecule. Swelling occurs only in the amorphous structural zones of the terpolymer. It is therefore a measure of the quality and content of the continuous phase. As a physical phenomenon indicates an internal cross-linking of the polymer and describes its physical structure.
Absorbability increases with increasing mobility of the macromolecules and decreases with an increase in cohesive energy between them. The obtained results of swelling in water indicate for a hydrophobic character of all the prepared polymers.
An increase in the number of carbons separating the terephthalate groups in the ester block of TPEEAs causes an increase of absorbability of benzene and decrease of hardness, due to an increase in amorphous phase content.
Flexible blocks create more and better polymer matrix and the content of crystalline phase decreases. It results in the relaxation of the structure and distance from other polymer macromolecules, thus easier benzene penetration into the material and less rigidity. Obtained copolymers had all characteristic bands for esters, aliphates or ether, and amides, which are presented in Table 4.
Chemical structure of new materials was also verified with 13 C NMR spectroscopy [31—34] and the results with peak assignments are presented in Figures 5 and 6.
Analysis of the 13 C NMR spectra showed the presence of all characteristic groups present in the esters, ethers or fatty acids, and amides. Signals are noted in the range On the 13 C NMR spectrum the peak presence at However, one should bear in mind that the terpoly ester-ether-amide s and terpoly ester-aliphatic-amide s are random block polymers.
Chemical shifts ppm of terpoly ester-ether-amides and terpoly ester-aliphatic-amides. It is a measure of the quality of the spatial network of the elastomer. It is a measure of the quality of the continuous phase capable of viscoelastic response. The area C is proportional to the accumulated energy.
Received two types of mechanical hysteresis loops. Better mechanical properties, but worst elastic residues have terpolymers where the amorphous phase is DLAol series II.
This is probably due to the lower weight content of flexible blocks in the terpolymers. Terpolymers of this series, similar to PEE and PEA, exhibit a large part of energy accumulated during the first cycle of elongation.
The probable cause is the strong interactions at the domain-matrix contact in these materials, due to hydrogen bonds, Van der Waals forces, or through Chain foldings. The mechanical hysteresis loops of terpoly ester-ether-amide s series I demonstrate that there is in these materials a small energy accumulation in the first cycle. Therefore, they are elastomers with a better mechanical shape memory than terpoly ester-aliphatic-amide. The most intense diffraction peaks appear in doublets.
The diffraction pattern of PA12 homopolymer has one wide diffraction maximum with two extreme points: The qualitative analysis of the diffactograms Figures 9 and 10 suggests that in the obtained terpolymers composed of the ester and amide hard blocks, only the amide block is responsible for the formation of the crystalline phase.
For all the series, terpolymers where the ester block is trimethylene terephtalate exhibits poor-shaped and very wide diffraction maximum.
This may indicate the weakest capacity for crystallization of these polymers. The DSC curves of multiblock elastomers can be divided into two parts. The influence of chemical compositions of ester block on the thermal properties and on the values of phase change temperatures of the products are presented in Table 6 and are shown in Figures 11 — Probably, further increase in T g1 is responsible for the terpolymers dissolution of the short ester sequence in the soft phase.
The poor-shaped melting endotherm is observed in the low-temperature region in terpolymers of series I. It determined the heat of fusion of the soft phase. With the increase of the number of carbons separating the terephthalate groups in the ester block of terpolymers also increased the melting point temperature of the crystalline fraction of PTMO blocks. This shows that the purity of the PTMO soft phase increases.