Thermotropic liquid crystal reinforced polycarbonate photovoltaic backplane laminating machine
DATE：2021/7/17 8:37:21 / READ： / SOURCE：This station
Thermotropic liquid crystal reinforced polycarbonate photovoltaic backplane laminating machine
PC can also be enhanced by liquid crystal, the most used is thermotropic liquid crystal. In recent years, thermotropic liquid crystal polymer (TLCP) has been widely used to enhance PC blending, including the effects of TLCP addition on the melting and crystallization behavior, viscosity, morphology and mechanical properties of PC; As well as the application of Compatibilization technology in enhancement; PC contains a large number of benzene rings in its molecular chain, which has high rigidity and steric hindrance. Therefore, it has high melting temperature, high viscosity and difficult processing. It is difficult to make large thin-walled products, and the products are prone to stress cracking due to high residual stress. In addition, the heat resistance, strength and modulus of PC are lower than those of high performance engineering plastics such as polysulfone and polyimide, which limits the application of PC. Therefore, the enhancement of PC has become an important research topic. TLCP is a new type of high performance material with high modulus and high strength. In liquid crystal state, TLCP shows unique fluidity, excellent thermal stability and dimensional stability, chemical corrosion resistance, weather resistance, solvent resistance, low expansion coefficient and low density. By using the special structure and liquid crystal properties of TLCP, the melt processability and mechanical properties of PC can be improved. In the process of processing, TLCP can spontaneously orientate along the flow direction and form reinforcing fibers in situ, resulting in obvious shear thinning behavior and self reinforcing effect, so as to improve the processing performance of PC, reduce the processing energy consumption and improve the economy; Moreover, because the reinforcing phase is formed in situ in the matrix resin, compared with the traditional fiber (such as glass fiber and carbon fiber), TLCP reinforced PC has many advantages, such as wider processing range, improved appearance, reusable and so on. Photovoltaic backplane laminating machine www.handern.comEnhanced modification of thermotropic liquid crystal and polycarbonate: the liquid crystal copolyester of p-hydroxybenzoic acid (PHB) and polyethylene terephthalate (PET) is an aromatic semi-rigid copolyester, showing liquid crystalline state in a wide range of 230 ~ 310 ℃. Because the liquid crystal temperature is very close to the melting temperature range of PC, the TLCP can be blended with PC to reduce the melt viscosity of PC and improve the tensile strength, impact strength, tensile modulus and dimensional stability of PC. The PC / TLCP [M (PET) / M (PHB) = 40 / 60] system was studied. The results showed that: 1. Shear flow, especially the shear flow near the cortex, promoted the appearance of LCP rich fibers, and increased with the increase of TLCP aggregation degree. From the cortex to the core, the fibers gradually aggregated into ellipses; After annealing for 1 h, the glass transition temperature of the blends decreased by 50 ℃, and the mechanical properties changed obviously; When the amount of 3pc is low, the storage modulus decreases with the increase of time, and the strain increases to a certain value and then becomes plateau. The addition of PET / PHB can promote the crystallization of Po; PET / PHB mass fraction of 18% and 80% has the same enhancement effect, and PET / PHB mass fraction of 50% has the best enhancement effect. In addition, the synthesized liquid crystalline copolyesters bp-lcp and bpm-lcp were in-situ compounded with PC and PBT at different ratios, respectively, which had better in-situ reinforcement effect. Photovoltaic backplane laminating machine www.handern.com
Injection molding and tensile in-situ composite of thermotropic liquid crystal and polycarbonate: injection molding and in-situ composite of thermotropic liquid crystal cellulose aromatic ester (AEC) and PC can be carried out. The tensile modulus, bending modulus and strength of the composite increase with the increase of AEC content, and the tensile strength reaches the maximum when the AEC content is 10%. The change of mechanical properties of the composites is closely related to the number and morphology of the AEC liquid crystal microfibrils. Photovoltaic backplane laminating machine www.handern.com
PC / AEC was prepared by sj-20ax25 single screw extruder. The temperature of each zone was 230, 250, 260 ℃, and the rotation speed was 40R / min; Ps40e5ase precision injection molding machine was used for injection molding. The barrel temperature was 240, 260, 260 ℃, nozzle temperature was 260 ℃, mold temperature was 95 ℃, injection pressure was 150MPa, injection and holding time was 10s, and cooling time was 20s. With the increase of AEC content, the tensile modulus of the composite increases monotonously, and the increase is more obvious at low AEC content (less than 5%), which indicates that the rigidity of the composite can be improved by adding a small amount of AEC. The change of tensile strength with the content of AEC is more complex, which first decreases, then increases to the maximum and then decreases. The change process is closely related to the micro morphology of AEC in the composite. Photovoltaic backplane laminating machine www.handern.com
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