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Difference between single-component mortar and two-component mortar
Update time：2017-09-08 00:46:05clicks：2519次Type size：T|T
In the existing external wall insulation system, the application of mortar (mortar) is mainly in bonding mortar (mortar) and plastering mortar (mortar). According to the composition and supply form of mortar (mortar), it can be divided into single-component mortar and two-component liquid mortar.
The main admixture of single-component mortar is polyvinyl acetate ethylene copolymer and other components, plus cement and sand to mix dry powder materials in the field after mixing with water.
The two-component mortar is an organic polymer formed by the application of fiber-reinforced acrylic emulsion in the field to prepare cement in a certain proportion.
The advantage of single-component mortar is that it is cheap, relatively simple to transport and mix, and the proportion is controlled in the factory, which is relatively convenient for on-site construction. But the factory control ratio is also a double-edged sword, if the manufacturer is mercenary, do not pay attention to quality, and eventually the quality of the mortar in the user's hand is poor, the user is difficult to find.
The price of the two-component liquid glue is relatively high, and it is more complicated in transportation and on-site mixing, and it is best to arrange special personnel to be responsible for the preparation of the glue. As long as the qualified two-component liquid glue is prepared by special personnel on site, it can be convenient for Party A and the supervisor to supervise the quality of the glue, so that the quality of the two-component liquid glue is easier to be guaranteed.
As mentioned above, the main component of the single-component mortar is polyvinyl acetate and vinyl polymer, which is also commonly known as dispersible rubber powder. Dispersible rubber powder is made of polymer emulsion by spray drying processing, after drying rubber powder is gathered together spherical particles, soluble in water can form a stable dispersion liquid, and form an irreversible film after water loss, the same principle as emulsion film. However, after spray drying, the structure of polymer molecular chain is destroyed, so that the long molecular chain structure of emulsion becomes a solid powder short molecular chain structure, this process is irreversible. Therefore, the polymer mortar obtained after adding water is a discrete state of short molecular chain structure, which greatly reduces the anti-cracking and waterproof properties. In the microscopic structure, it can be found that the polymer formed by two-component liquid glue and cement is in a continuous state, and the polymer formed by one-component dry powder mortar with water is in a discrete state.
The unbroken long molecular chain makes the polymer deeply cross-linked, ensuring the continuous state of the polymer, which makes the polymer flexible and has good permeability. The flexibility enables the binder and the coating paste to adapt to the deformation caused by the thermal stress and internal stress of the external insulation system, which fundamentally ensures the durability and weather resistance of the external insulation system, especially the coating paste prepared with two-component liquid glue can adapt to complex climate changes without cracking. The good permeability enables the two-component liquid glue to penetrate into the binding void of the polystyrene particles of the EPS insulation board, thus greatly enhancing the bonding force between the glue and the insulation board, and will not fail to bond under complex climate change.
The two-component coating paste fully embodies the excellent film forming property, good elasticity and toughness, weather resistance and water resistance of acrylic polymer. In particular, its water resistance and weather resistance are very good.
Because the molecular chain is destroyed, the one-component dry powder mortar is in a discrete state with the polymer formed by water, and the performance of anti-cracking property and water absorption is very poor. Experiments have shown that the water permeability of the coating mortar prepared by polyvinyl acetate copolymer (dispersible rubber powder) is 4-10 times higher than that of acrylic polymer, and it does not have anti-cracking and waterproof properties. Therefore, the single-component plastering mortar needs to add hydrophobic agent or hydrophobic adhesive powder, and it is necessary to do waterproof and anti-crack putty after completing the plastering layer. However, hydrophobic monomers have been added to acrylic polymers during monomer polymerization.
Because of its short molecular chain structure and slight cross-linking between polymers, the combination degree of single-component mortar and insulation board is far less than that of two-component mortar with long molecular chain, and it is prone to bond failure under complex climate change and ultraviolet irradiation. Due to the large temperature difference of the west wall, the coating layer made of dry powder mortar has failed to bond, and the surface brick has fallen off. Single-component mortar originated in Europe, coupled with its relatively low cost, there are still applications in the European market, but the mainstream of the European and American markets is still two-component mortar.
Due to the low production cost and technical threshold of single-component dry powder mortar, a large number of manufacturers processing dry powder mortar have emerged in China in the past two years. By reducing the ratio of rubber powder to reduce the price, single-component dry powder mortar has been rapidly promoted and applied in the domestic market. Due to its uneven quality, it has caused many external wall insulation projects to fall off, peel off, crack and other phenomena. The external insulation industry has a serious crisis of trust, people can not distinguish the quality of the external insulation system, when doing external insulation concerns. Therefore, to improve the quality of the external insulation system, start with the selection of high-quality binders and plastering materials, rather than blindly pursuing the solution by increasing the safety structure of the system. Paying attention to the quality of mortar (mortar) materials is the only way to improve the safety and durability of external insulation systems.
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The main admixture of single-component mortar is polyvinyl acetate ethylene copolymer and other components, plus cement and sand to mix dry powder materials in the field after mixing with water.
The two-component mortar is an organic polymer formed by the application of fiber-reinforced acrylic emulsion in the field to prepare cement in a certain proportion.
The advantage of single-component mortar is that it is cheap, relatively simple to transport and mix, and the proportion is controlled in the factory, which is relatively convenient for on-site construction. But the factory control ratio is also a double-edged sword, if the manufacturer is mercenary, do not pay attention to quality, and eventually the quality of the mortar in the user's hand is poor, the user is difficult to find.
The price of the two-component liquid glue is relatively high, and it is more complicated in transportation and on-site mixing, and it is best to arrange special personnel to be responsible for the preparation of the glue. As long as the qualified two-component liquid glue is prepared by special personnel on site, it can be convenient for Party A and the supervisor to supervise the quality of the glue, so that the quality of the two-component liquid glue is easier to be guaranteed.
As mentioned above, the main component of the single-component mortar is polyvinyl acetate and vinyl polymer, which is also commonly known as dispersible rubber powder. Dispersible rubber powder is made of polymer emulsion by spray drying processing, after drying rubber powder is gathered together spherical particles, soluble in water can form a stable dispersion liquid, and form an irreversible film after water loss, the same principle as emulsion film. However, after spray drying, the structure of polymer molecular chain is destroyed, so that the long molecular chain structure of emulsion becomes a solid powder short molecular chain structure, this process is irreversible. Therefore, the polymer mortar obtained after adding water is a discrete state of short molecular chain structure, which greatly reduces the anti-cracking and waterproof properties. In the microscopic structure, it can be found that the polymer formed by two-component liquid glue and cement is in a continuous state, and the polymer formed by one-component dry powder mortar with water is in a discrete state.
The unbroken long molecular chain makes the polymer deeply cross-linked, ensuring the continuous state of the polymer, which makes the polymer flexible and has good permeability. The flexibility enables the binder and the coating paste to adapt to the deformation caused by the thermal stress and internal stress of the external insulation system, which fundamentally ensures the durability and weather resistance of the external insulation system, especially the coating paste prepared with two-component liquid glue can adapt to complex climate changes without cracking. The good permeability enables the two-component liquid glue to penetrate into the binding void of the polystyrene particles of the EPS insulation board, thus greatly enhancing the bonding force between the glue and the insulation board, and will not fail to bond under complex climate change.
The two-component coating paste fully embodies the excellent film forming property, good elasticity and toughness, weather resistance and water resistance of acrylic polymer. In particular, its water resistance and weather resistance are very good.
Because the molecular chain is destroyed, the one-component dry powder mortar is in a discrete state with the polymer formed by water, and the performance of anti-cracking property and water absorption is very poor. Experiments have shown that the water permeability of the coating mortar prepared by polyvinyl acetate copolymer (dispersible rubber powder) is 4-10 times higher than that of acrylic polymer, and it does not have anti-cracking and waterproof properties. Therefore, the single-component plastering mortar needs to add hydrophobic agent or hydrophobic adhesive powder, and it is necessary to do waterproof and anti-crack putty after completing the plastering layer. However, hydrophobic monomers have been added to acrylic polymers during monomer polymerization.
Because of its short molecular chain structure and slight cross-linking between polymers, the combination degree of single-component mortar and insulation board is far less than that of two-component mortar with long molecular chain, and it is prone to bond failure under complex climate change and ultraviolet irradiation. Due to the large temperature difference of the west wall, the coating layer made of dry powder mortar has failed to bond, and the surface brick has fallen off. Single-component mortar originated in Europe, coupled with its relatively low cost, there are still applications in the European market, but the mainstream of the European and American markets is still two-component mortar.
Due to the low production cost and technical threshold of single-component dry powder mortar, a large number of manufacturers processing dry powder mortar have emerged in China in the past two years. By reducing the ratio of rubber powder to reduce the price, single-component dry powder mortar has been rapidly promoted and applied in the domestic market. Due to its uneven quality, it has caused many external wall insulation projects to fall off, peel off, crack and other phenomena. The external insulation industry has a serious crisis of trust, people can not distinguish the quality of the external insulation system, when doing external insulation concerns. Therefore, to improve the quality of the external insulation system, start with the selection of high-quality binders and plastering materials, rather than blindly pursuing the solution by increasing the safety structure of the system. Paying attention to the quality of mortar (mortar) materials is the only way to improve the safety and durability of external insulation systems.
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