Polyvinyl chloride (PVC) is a cheap and readily available polymer material with a wide range of applications in industries such as footwear, pipe fittings, wire and cable, and calendered films.However, the poor toughness and lack of thermal stability of pure PVC materials have limitations in many applications.Therefore, in many industries, PVC composites modified with various fillers have been developed to improve their mechanical properties and thermal stability.

If you add a certain amount of calcium carbonate (CaCO3), the hardness of PVC products is improved, the overall performance is improved, the production cost can also be controlled.With the deepening of the research, it has been found that the easy processing characteristics of calcium carbonate can greatly improve its application value and potential in PVC materials.

Comparison of different calcium carbonate applications in PVC materials

1、Wet Calcium Heavy

Deng Kewen et al. applied Guangyuan dry milled heavy calcium (GY616), Guangyuan wet milled ultra-white ultra-fine heavy calcium carbonate (CC-6000A), and commercially available light calcium to the base formulation of PVC calendering film respectively, and analyzed the effects of the calcium carbonate varieties on the glossiness, tensile strength, specific gravity, covering power, and heat resistance of the prepared films.Among them, the gloss and specific gravity of the calendered film with the addition of wet heavy calcium were consistent with that of the composite lightweight nano-calcium, and the tensile strength was improved, with better covering power and heat resistance.The effects of gloss, tensile strength, specific gravity, covering power and heat resistance of CC-6000A and calcium composite lightweight nano-calcium applied in car sticker film were comparatively analyzed by using four formulation systems; the gloss and tensile strength of the car sticker film prepared by the CC-6000A system were higher than that of the calcium composite lightweight nano-calcium, with the same specific gravity, and better covering power and heat resistance.

2、Calcium carbonate nanoparticles

Liu Yaxiong et al. investigated the effects of key factors such as carbonization onset temperature, fatty acid C-chain length, oil melting point and iodine value, and composite surface treatment agent on the properties of nano-calcium carbonate and polyvinyl chloride (PVC) calendered film.The results showed that, when the carbonization starting temperature was 24℃, the generated calcium carbonate was regular cubic, the specific surface area was 22.3m2/g, the average particle size was 80nm, the whiteness was 96%, the particle agglomeration was less, the secondary particle size was the smallest, and the D50 was 0.43 μm; the calendering film prepared with this calcium carbonate had the highest gloss, the best ink absorption, and the best overall performance.

Xie Zhong et al. used limestone as raw material to generate lime by calcination, and produced calcium carbonate nanoparticles by double-tower continuous carbonization method.They researched the surface treatment agent composed of fatty acid, vegetable oil, nonionic surfactant, coupling agent, etc., and figured out the 3-step surface activation treatment process of calcium carbonate to produce nanoactivated calcium carbonate with low oil-absorption value, good processing performance and good dispersion, which was applied as a filler and reinforcing agent in the production of PVC drainage pipe, and the tensile yield strength, elongation at break, and longitudinal retraction of PVC drainage pipe were produced,Flat test and other indicators are better than the national standard for PVC pipe, 30 tons of heavy trucks from the top of the drainage pipe pressure, but still for the water pipe to restore the original shape, the product has excellent performance.

3、Calcium carbonate in different forms

Dong Dongdong et al. prepared five kinds of calcium carbonate particles with different shapes, namely, flake, rhombus, rod, sphere and cube, by chlorination method, and investigated the effect of different calcium carbonate particle morphology on the mechanical properties of soft PVC films.The results show that different shapes of calcium carbonate have improved the mechanical properties of PVC film, PVC film tensile strength and elongation at break have increased significantly; among them, the rod-shaped shape of calcium carbonate has the best effect on the mechanical properties of PVC film, the tensile strength of 27.11MPa; rhombic calcium carbonate modified PVC film has the highest elongation at break, which is 98.23%.

Hu Hongchuan et al. investigated the effects of calcium carbonate, heat stabilizer, and ACR impact modifier on the mechanical properties of highly filled PVC pipes.The test results showed that with the increase of calcium carbonate dosage, the tensile properties of PVC pipe gradually decreased, and the impact strength and bending strength increased.

4、Calcium carbonate compounded with talc

Li Na et al. prepared PVC/calcium carbonate/talc composites by melt blending process, and investigated the effects of talc and calcium carbonate on the mechanical properties and processing properties of PVC composites.The results showed that the Vicat softening temperature of PVC composites was the highest (78.6℃) when the mass ratio of calcium carbonate to talc was 10∶20; the bending strength of PVC composites was the highest (77.81MPa) when the mass ratio of calcium carbonate to talc was 15∶15; the notched impact strength of PVC composites was the highest (77.81MPa) when the mass ratio of calcium carbonate to talc was 20∶10; the notched impact strength of PVC composites was the highest (77.81MPa) when the mass ratio of calcium carbonate to talc was 20∶10.7.738kJ/m2); calcium carbonate and talc compound ratio of 5:25, PVC composite materials, the highest bending modulus (6300MPa).

5、Modified calcium carbonate

The effect of type and content of calcium carbonate on the properties of PVC/CaCO3 composites was investigated by Dongdong Yang et al.The results showed that calcium carbonate modified by stearic acid and titanate coupling agent composite had the best effect on the comprehensive performance improvement of the composites, and the impact strength was increased by 15% compared with the composites with unmodified calcium carbonate added.

Deng Chuanfu et al. explored the effect of modified nano-CaCO3 on the comprehensive performance of PVC composites.The results showed that by introducing excessive hydroxyl groups in the wet modification stage of nano-CaCO3, it helps to enhance the graft-coating effect of silane coupling agent, and the nano-fillers with better dispersibility and processability can be obtained, which can effectively improve the thermal stability performance of PVC composites, promote plasticization, and achieve the reinforcing and toughening effect of composites.

6、No added calcium carbonate

Zhang Weifang et al. prepared uniformly dispersed calcium carbonate nano-emulsions by microemulsification, and then synthesized two nano-CaCO3/PVC composite resins by in-situ polymerization.The nano-CaCO3/PVC composite resins showed a simultaneous increase in the apparent density and plasticizer uptake, a better thermal stability, an increase in the notched impact strength, and an increase in the elongation at break, as compared to the blank resins.

concluding remarks

At present, the rapid development of domestic specialized calcium carbonate, category obvious growth, but on the basis of the high-end products produced is still relatively small, product value-added enhancement there is still some space. calcium carbonate for PVC is a relatively mature specialized products, the research results have a certain degree of systematic, on the selection of calcium carbonate, the use of modifiers, the control of the processing process have certain results, it is worthwhile to learn from and development.

Last Article：What problems can we solve for you?

Next Article：PVC follow-up further attention to export performance and macro-driven can drive the stage market.