BOPET biaxially oriented film production line
DATE：2021/5/26 8:47:13 / READ： / SOURCE：This station
BOPET biaxially oriented film production line
Blending modification of polycarbonate vinegar and polyenzymePC has high melt viscosity, poor fluidity, solvent resistance, wear resistance and low notched impact strength. Poly (butylene terephthalate) (PBT) is a kind of thermoplastic engineering plastics with fast crystallization rate, which has excellent solvent resistance and good melt fluidity.
The main chains of PC and PBT contain benzene ring and ester group, and their chemical structures are similar, so they have good compatibility. The obtained alloy has good heat resistance, impact resistance, processability and chemical resistance, and is a blend with high industrial application value. Compared with PC, the toughness of PC / PBT Alloy is poor, so it is usually necessary to add impact modifier to improve the toughness of the alloy and obtain the material with practical value.
PC is an amorphous polymer, while PBT and pet are crystalline polymers. PC / Pet blends are typical amorphous / crystalline blends. Both PC and PBT have phenyl groups on their molecules. Some structural similarities make PC and PBT (or PET) have certain compatibility, which belongs to partially compatible system. One of the most important reasons for the partial compatibility of PC with PBT or pet is the transesterification reaction between PC and PBT or pet in the process of melt blending, resulting in the formation of copolymer of PC and PBT or pet. The copolymer is compatible with the component PC and PBT or pet, which reduces the interfacial tension between the two phases, improves the two-phase adhesion, and improves the two-phase compatibility. The compatibility of PC with PBT or pet varies with the degree of transesterification. With the continuous transesterification, single-phase blends can be formed. BOPET biaxially oriented film production line www.handern.com
PC is amorphous polymer, while PBT and pet are copolymer. PC / poly coordination metal is typical copolymer
With the continuous exchange reaction, the blends gradually homogenized and finally formed single-phase blends. In the process of melt blending with PBT or pet, the copolymer of PC and PBT or pet is formed. The copolymer is compatible with the component PC and PBT or pet, which reduces the interfacial tension between the two phases, improves the adhesion between the two phases and improves the compatibility between the two phases. The compatibility of PC with PBT or pet varies with the degree of exchange reaction. It is controversial whether PC is compatible with PBT or pet without exchange reaction. Some people add ester exchange reaction inhibitor into PC / FBT blends. DSC is used to determine that the PC / PBT Blends with different proportions are t, and there are two blends, It shows that the PC / PBT (PET) alloy is a two-phase structure. With the decrease of PC content, the mechanical properties of PC phase increase, that is, the glass transition temperature of the blends moves inward, which is the performance of partial compatibility of the blends. It can be seen that PC / PBT Blends without cool exchange reaction are still partially compatible. BOPET biaxially oriented film production line www.handern.com
The compatibility of PC / PBT Alloy is not very good, and phase separation occurs during blending, which can be seen from the interaction parameter X of PC and PBT. The smaller the interaction parameter, the better the compatibility. The interaction parameter X of PC and PBT with a certain degree of polymerization is shown in table 5-29. The critical interaction parameter between PC and PBT is 0.025. Comparing with the critical interaction parameter, all X. values in the table are greater than the critical values. This shows that the compatibility of PC and PBT is limited, that is, the two parts are not compatible
Compatible. The compatibility of PC / PBT Alloy can also be judged by measuring the torque of PC / PBT Blends. The torque quotient of the blends is positive, and the mixing addition rule indicates that the blends are completely compatible; The torque of PC / PBT Blends is lower than the linear addition value, and the torsion of partial blends is negative, which indicates that PC / PBT alloys are not completely compatible. BOPET biaxially oriented film production line www.handern.com
Author：admin