News Details
Chain extender for polyurethane elastomer mechanical properties
2017-2-24 23:21:22
Chain extender for polyurethane elastomer mechanical properties and the effect of pre polymers NCO content on the mechanical properties of polyurethane elastomer. With pre polymers the increase of the content of NCO based polyurethane elastomer hardness, modulus and tear strength increased significantly, elongation and elastic fell slightly, the tensile strength increased slowly. When pre polymers NCO % within 8 ~ 9, the highest hardness, modulus and strength, its reason is to improve the pre polymers NCO content, but also improve the molar ratio of isocyanate and hydroxyl, increase the hard segment content of polyurethane, cohesive energy density increases, resulting in stiffness, strength and modulus increase.
Preparation with KC chain extender, the mechanical properties of polyurethane elastomer. Pre polymers NCO content increasing, the change of the mechanical properties of polyurethane elastomer as described above. BDO - PU hardness, elongation, impact elasticity and high tear strength, KC - PU only 300% high modulus, the tensile strength of the PU close to both. When pre polymers NCO % = 8.3, KC - PU and approximate NCO % content of BDO - PU comprehensive performance. But KC - PU during vulcanizing demoulding can shorten the time and the production of products is very useful.
The ternary alcohol content on the mechanical properties of polyurethane elastomer. With soft period of relative molecular mass of 1000 PTMG/MDI as the pre polymers, fixed NCO % = 6.1, using glycol and ternary alcohol mixture as chain extender, change its three yuan alcohol dosage, the preparation of 6 kinds of polyurethane elastomer. The mechanical properties of polyurethane elastomer with small molecules, an increase in the amount of the ternary alcohol, besides modulus are decreasing. Ternary alcohol consumption is equal to or less than 20%, the relatively small decline in performance.
This because when ternary alcohol consumption is low, chemical crosslinking density is low, chemical crosslinking network crosslinking of smaller, and hard segment in micro area form the physical junction of crosslinking. At this time of hardness, tensile strength and impact elasticity change smaller, and tear strength change is bigger. But the improvement of modulus may be elastomer chemical crosslinking and physical crosslinking between molecules in synergy.
With ternary alcohol dosage, chemical density increases, the hardness and strength of the elastomer and elastic drop sharply, possible reason is that the chemical crosslinking structure increases, destroyed the regularity of the molecular chain, limits the activity of the chain, reduce the crystallization ability of the elastomer, so that the mechanical performance degradation. When the ternary alcohol consumption is more than 20% ~ 30%, the elastomer mechanical properties reduced too.
Product Name: Diethyl Methyl Benzene Diamine (Ethancure100) DETDA
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
MOCA mechanical properties of polyurethane elastomer. Pre polymers prepared from MDI activity is higher, with amine, such as the chain extender MOCA curing reaction speed, operation time is short, but the use of mixed amine and alcohol after the chain extender, can reduce the reaction speed, to extend the time of gel.
NCO content is not high, in the process of the polymers and MOCA - PU 300% hardness and modulus are higher. When pre polymers NCO mass fraction of about 8.3%, 300% of MOCA/KC - PU modulus is greater than the KC - the modulus of PU 14.2 MPa and BDO - PU modulus of 3.9 MPa, and the hardness of the three elastomer. This shows that under a certain hardness, in order to improve the modulus of polyurethane elastomer, all can be used to join a small amount of amine chain extender can get higher modulus.
Of eight kinds of PU elastomer 1 HNMR and 13 CNMR spectra has carried out detailed research, references to the spectral peak interpreted in detail, and one by one. [glycol ester - H12MDI - polytetrahydrofuran glycol] 1 HNMR and 13 CNMR spectrum of the PU. The spectral peak and PU possible structure comparison, the H atoms are as follows: the relation between H11.60, H23.39, H34.02, H4, 10 4.55 ~ 4.90, H53.75, H61.95, H70.94-1.71, H83.39, H91.07, H114.21 (solvent: CDCl3). Each delta value of C atom: C126.47, C270.57, C364.36, C547.05, 50.33, C6, 725.89 ~ 33.61, C832.62, 33.69, C942.90, 44.03, C1162.97, C12155.90, C13155.31 (solvent: CDCl3)
For the other seven kinds of chain extender of polyurethane (pu) 1 h-nmr and 13 c - NMR test, determine the molecular structure of polyurethane, results show that the polymer reaction obtained the expected: [glycol ester polytetrahydrofuran backwards diethylene glycol - H12MDI -] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 3 propanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 2 propanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 4 butanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 3 butanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 5 e glycol] polyurethane and [glycol ester polytetrahydrofuran H12MDI - 1, 6 f glycol] polyurethane.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Preparation with KC chain extender, the mechanical properties of polyurethane elastomer. Pre polymers NCO content increasing, the change of the mechanical properties of polyurethane elastomer as described above. BDO - PU hardness, elongation, impact elasticity and high tear strength, KC - PU only 300% high modulus, the tensile strength of the PU close to both. When pre polymers NCO % = 8.3, KC - PU and approximate NCO % content of BDO - PU comprehensive performance. But KC - PU during vulcanizing demoulding can shorten the time and the production of products is very useful.
The ternary alcohol content on the mechanical properties of polyurethane elastomer. With soft period of relative molecular mass of 1000 PTMG/MDI as the pre polymers, fixed NCO % = 6.1, using glycol and ternary alcohol mixture as chain extender, change its three yuan alcohol dosage, the preparation of 6 kinds of polyurethane elastomer. The mechanical properties of polyurethane elastomer with small molecules, an increase in the amount of the ternary alcohol, besides modulus are decreasing. Ternary alcohol consumption is equal to or less than 20%, the relatively small decline in performance.
This because when ternary alcohol consumption is low, chemical crosslinking density is low, chemical crosslinking network crosslinking of smaller, and hard segment in micro area form the physical junction of crosslinking. At this time of hardness, tensile strength and impact elasticity change smaller, and tear strength change is bigger. But the improvement of modulus may be elastomer chemical crosslinking and physical crosslinking between molecules in synergy.
With ternary alcohol dosage, chemical density increases, the hardness and strength of the elastomer and elastic drop sharply, possible reason is that the chemical crosslinking structure increases, destroyed the regularity of the molecular chain, limits the activity of the chain, reduce the crystallization ability of the elastomer, so that the mechanical performance degradation. When the ternary alcohol consumption is more than 20% ~ 30%, the elastomer mechanical properties reduced too.
Product Name: Diethyl Methyl Benzene Diamine (Ethancure100) DETDA
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
MOCA mechanical properties of polyurethane elastomer. Pre polymers prepared from MDI activity is higher, with amine, such as the chain extender MOCA curing reaction speed, operation time is short, but the use of mixed amine and alcohol after the chain extender, can reduce the reaction speed, to extend the time of gel.
NCO content is not high, in the process of the polymers and MOCA - PU 300% hardness and modulus are higher. When pre polymers NCO mass fraction of about 8.3%, 300% of MOCA/KC - PU modulus is greater than the KC - the modulus of PU 14.2 MPa and BDO - PU modulus of 3.9 MPa, and the hardness of the three elastomer. This shows that under a certain hardness, in order to improve the modulus of polyurethane elastomer, all can be used to join a small amount of amine chain extender can get higher modulus.
Of eight kinds of PU elastomer 1 HNMR and 13 CNMR spectra has carried out detailed research, references to the spectral peak interpreted in detail, and one by one. [glycol ester - H12MDI - polytetrahydrofuran glycol] 1 HNMR and 13 CNMR spectrum of the PU. The spectral peak and PU possible structure comparison, the H atoms are as follows: the relation between H11.60, H23.39, H34.02, H4, 10 4.55 ~ 4.90, H53.75, H61.95, H70.94-1.71, H83.39, H91.07, H114.21 (solvent: CDCl3). Each delta value of C atom: C126.47, C270.57, C364.36, C547.05, 50.33, C6, 725.89 ~ 33.61, C832.62, 33.69, C942.90, 44.03, C1162.97, C12155.90, C13155.31 (solvent: CDCl3)
For the other seven kinds of chain extender of polyurethane (pu) 1 h-nmr and 13 c - NMR test, determine the molecular structure of polyurethane, results show that the polymer reaction obtained the expected: [glycol ester polytetrahydrofuran backwards diethylene glycol - H12MDI -] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 3 propanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 2 propanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 4 butanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 3 butanediol] polyurethanes, [glycol ester polytetrahydrofuran H12MDI - 1, 5 e glycol] polyurethane and [glycol ester polytetrahydrofuran H12MDI - 1, 6 f glycol] polyurethane.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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