Research status and application of the hottest pet

Research status and application of pet/pe co mixed gold (II)

compatibilizer compatibilizer PET/PE/compatibilizer ternary blend system is mainly studied around the compatibility or interaction between pet and compatibilizer, and the compatibility between PE and compatibilizer. These compatibilizers include random copolymers, block copolymers, graft copolymers, ionomers, etc. According to the compatibilization mechanism, it can be divided into non reactive compatibilization, Reactive Compatibilization and special interaction compatibilization

2.1 non reactive compatibilizers compatibilize PET/PE Blends

copolymers with similar structures to pet and PE can compatibilize PET/PE blends, such as (styrene/ethylene/butadiene/styrene) copolymer (SEBS), (styrene/ethylene/propylene) copolymer (s-ep), ethylene propylene diene monomer (EPDM), ethylene propylene rubber (EPR), (polyethylene terephthalate/polyethylene) copolymer (pet-b-pe), etc. These copolymers act as surfactants at the phase interface of PET/PE, reduce the interfacial tension, increase the interfacial bonding strength, reduce the size of dispersed phase, and improve the compatibility of the blend system

traugott et al. Used SEBS and EPR as compatibilizers of PET/HDPE blends, and studied the effect of compatibilizer content on the morphology and properties of the blends. With the increase of SEBS content, the strength and rigidity of PET/HDPE decreased; Only adding a small amount of SEBS can significantly improve the elongation at break. When the content of SEBS reaches 20%, the blend is not broken within the range of Instron universal material testing machine. The effect of EPR is much worse than SEBS

curry et al. Studied the effect of s-ep as a compatibilizer on the mechanical properties of recycled polyethylene terephthalate/recycled high density polyethylene (rpet/rhdpe) blends. They believed that because the styrene segment of s-ep was compatible with pet with similar solubility parameters, s-ep was compatible with PE and could reduce the crystallinity of PE. Therefore, s-ep had a good compatibilization effect on PET/HDPE in a large content range. Even if the crystalline continuous phase is formed, the blends still have good toughness and impact properties

2.2 reactive compatibilizers compatibilize PET/PE Blends

reactive compatibilizers compatibilize PET/PE blends is an effective means to improve the compatibility of pet/pe. Such compatibilizers mainly include polyolefin grafting and block copolymers. In terms of structure, their matrix is compatible with PE, and the functional groups carried by them, such as epoxy group, anhydride group, carboxyl group, ester group, etc., react with hydroxyl group, carboxyl group, ester group in pet to form copolymers in situ through addition, esterification, transesterification and other reactions, playing the role of compatibilizers. Among them, the graft copolymer and block copolymer of glycidyl methacrylate and olefins have the best effect

(1) MAH graft copolymer compatibilizer

MAH graft copolymer compatibilizers include Polyethylene Grafted Maleic Anhydride (PE-g-MAH), (styrene/ethylene/butadiene/styrene) copolymer grafted maleic anhydride (SEBS-g-MAH), (ethylene/propylene 3. Power analyzer methyl enoate/maleic anhydride) copolymer (e-mea-g-mah), etc. Due to the reversible esterification reaction between maleic anhydride and the terminal hydroxyl group of pet at high temperature, the chemical reactivity between pet and MAH graft is poor under the blending condition. Therefore, the interface interaction is mainly dispersive force and acid-base interaction. In order to further improve the interface interaction, epoxy compound interface modifier can be added. Among MAH grafts, SEBS-g-MAH has the best compatibilizing effect. PET/PE (50/50) blends with SEBS-g-MAH with grafting ratio of 2% are super tough blends with elongation at break of 600%

(2) glycidyl methacrylate (GMA) graft or copolymer compatibilizer

GMA graft or copolymer compatibilizers include polyethylene graft glycidyl methacrylate (pe-g-gma), (ethylene/glycidyl methacrylate) copolymer (e-gma), (ethylene/ethyl acrylate/glycidyl methacrylate) copolymer (e-ea-gma), etc. GMA can react with both the hydroxyl end group and the carboxyl end group of pet, and the copolymer formed in situ at the interface of the blend has a good compatibilization effect. By comparing the morphological structure, rheological properties, thermal properties and mechanical properties of the blends, the compatibilization of the commonly used MAH and GMA modified copolymers has the following order: e-gma> e-ea-gma> SEBS-g-MAH> e-mea-g-mah. It can be seen that the copolymer modified by GMA is a good compatibilizer for PET/PE

(3) other functional copolymer compatibilizers

functional part copolymers with carboxyl, ester and amide structures also have compatibilization effects on pet/pe blends, such as Polyethylene Grafted methyl methacrylate (pe-g-mma), Polyethylene Grafted hydroxyethyl methacrylate (pe-g-hema), Polyethylene Grafted ethyl acrylate (pe-g-ea), Polyethylene Grafted maleimide (pe-g-mi), (ethylene/vinyl acetate) copolymer (E/VAC) (ethylene/acrylic acid) copolymers (EAA) and so on. Most of these copolymers realize the compatibilization of PET/PE blends through esterification or transesterification. Because the esterification or transesterification reaction is difficult to be fully carried out at the processing temperature, it is difficult to obtain a good compatibilization effect

in order to promote esterification or transesterification, he Hui et al studied the compatibilization of E/VAC and EAA on HDPE/PET (75/25) blends catalyzed by transition metal catalysts. Chemical analysis and spectral analysis showed that the catalytic esterification or transesterification reaction played the role of compatibilizer for the copolymer formed by more intelligent topography; Under the action of catalyst, E/VAC and EAA improved the rheological properties and heat resistance of HDPE/PET Blends. The tensile and impact properties of ternary blends were significantly higher than those of HDPE/PET Blends. It has guiding significance for the high performance of HDPE

2.3 new methods, special compatibilizers compatibilizer PET/HDPE alloy

with the diversification of blending modification and processing methods, new means such as electronic radiation have also been applied to the blending modification of PET/PE. Ionomer compatibilizer is a special compatibilizer that has attracted research interest in recent years. For blends containing crystalline polymers, ionomers can act as both compatibilizers and nucleators. In addition to esterification and transesterification, the interaction between ionomer compatibilizer and pet may also have special effects such as ion dipole, complex coordination, physical crosslinking of ion clusters and so on

kalfoglou used (ethylene/acrylic acid) copolymer sodium salt (surlyn1605) as compatibilizer of PET/LLDPE BLEND system. The compatibilization effects of different pet/lldpe ratios and ionomer (Surlyn) content were studied. The blend PET/LLDPE/Surlyn (68.2/22.7/9.1) has good mechanical properties. Based on the compatibility study of pet/surlyn blends, it is considered that the strong bonding effect of pet/surlyn two-phase interface is the fundamental reason for compatibilization

mascaj et al. Mixed phenoxy polymer (polyhydroxyether of bisphenol A) with maleic anhydride of ethylene propylene copolymer to obtain graft copolymer, and then mixed with sodium salt of (ethylene/acrylic acid) copolymer (surlyn8660) to enhance ionic properties with sodium phenol and sodium ethanol to obtain homoionic mixture, and used the graft and blend for Compatibilization. These two compatibilizers are beneficial to the dispersion of pet or HDPE, because they are both effective surfactants. The addition of ionomer continuously increases the melt viscosity of the blend, but only the homoionic mixture has a substantial improvement on the tensile strength and elongation at break of the blend. This is because the mixture has a strong nucleation effect on the crystallization of the blend. Relying on its excellent performance and leading technology, the 3D printing material enhances the bonding of the polymer two-phase interface

Xi Shiping studied the effect of Low Density Polyethylene Grafted lanthanum maleate (ldpe-g-mala) on the crystallization behavior and mechanical properties of PET/LDPE Blends as more and more investors entered the shared bicycle market. The impact strength and tensile strength of PET/LDPE/ldpe-g-mala (80/18/2) blends were increased by 40% and 25% respectively; Compared with PET/LDPE (80/20), it increased by 170% and 30% respectively. When the content of ionomer increases to 5%, the comprehensive properties decrease. With the increase of ionomer content, the melt crystallization temperature (TCC) increases and the cold crystallization temperature (TCH) decreases. The increase of TCC indicates that the ionomer has nucleation effect on pet, and the decrease of TCH indicates that the flexible molecular chain of ionomer has a certain promoting effect on the molecular motion of pet

3 application prospect of PET/PE Blend gold

the purpose of modifying pet with PE is to improve the rheological properties of pet, accelerate the crystallization speed of pet, improve the impact properties of pet, and reduce the water absorption of pet, so as to obtain a blend alloy with high tensile strength, high toughness, high crystallinity, and high temperature resistance. This has broad application prospects for using low-cost pet instead of other high-cost engineering plastics in the fields of electronics, transportation, machinery and meters, and making full use of a large number of recycled PET

the purpose of modifying PE with pet is to improve the mechanical properties and heat resistance of PE, so as to obtain high-performance PE. If appropriate processing methods are adopted to disperse pet in PE matrix with layered structure, the solvent resistance of pet can be used to improve the barrier performance of packaging products and hollow containers made of PE alloy. Jinyangguang et al. Used EAA to compatibilize hdpe/pet (80/20) blends, and obtained a layered dispersion structure with pet as the dispersed phase. The lamellar tendency of pet increases with the increase of phase compatibility of the system; However, when the content of compatibilizer exceeds a certain value, the layered dispersed phase is destroyed from the center. Low melting temperature, low shear rate and high forming temperature are conducive to the maintenance of large size of dispersed phase, the occurrence of radial deformation and the formation of layered dispersed structure

4 conclusion

in the pet/pe co mixed gold system, no matter which alloy form is blended, it has practical significance for improving the comprehensive properties of pet and PE, broadening the application range of pet and PE, especially recycling PET or PE