Effect Of Compatibilizer Research Articles

Modification of polylactide by poly(ionic liquid)-b-polylactide copolymer and bio-based ionomers: Excellent toughness, transparency and antibacterial property

Polylactide (PLA) is one of the most attractive bioplastics as it can be produced from nontoxic renewable feedstock. However, its inherently poor toughness greatly limits its large-scale application. Cost-effectively toughening PLA without sacrificing its transparency remains a big challenge. We herein prepared an imidazolium-based poly(ionic liquid)-b-PLA copolymer (ILA) and ionomers as toughening agent for PLA through an integrative approach including continuous-monomer-feeding copolymerization, quaternization reaction, ion exchange and inter-ionomers blending. By blending PLA with the ILA and ionomers, we successfully obtained PLA materials with combined features including high toughness, good transparency and antibacterial properties. The effects of regulated ionomer composition and ILA compatibilizer on phase morphology, mechanical properties and transparency of the blends were systematically studied. The optimum formulation (PLA/E12/ILA 60/40/5) shows an impressive transmittance of 89–93 %, high impact strength of 45 kJ/m2 and elongation at break at 170 %, which are about 17 and 24 times that of pure PLA, respectively. More interestingly, the presence of imidazolium cation and anion groups endows the blends with attractive antibacterial properties. Ion exchange between ILA copolymer and the imidazolium-containing ionomeric system leads to a synergistic effect of compatibilization and efficient toughening, providing a new strategy for develop high performance PLA materials.

Effect of compatibilizer on the structure and property of polycarbonate/polypropylene alloys

AbstractPolycarbonate/Polypropylene (PC/PP) alloy is a typical thermodynamically incompatible system. In this work, ethylene‐methyl acrylate copolymer (EMA), methoxamine hydrochloride‐grafted POE (POE‐g‐MAH), ethylene‐butyl acrylate‐glycidyl methacrylate copolymer (EAY), a self‐made compatibilizer (PPM‐g‐GMA) of a mixture of glycidyl methacrylate grafted PP (PP‐g‐GMA) and glycidyl methacrylate‐grafted POE (POE‐g‐GMA) were selected as compatibilizer to prepare PC/PP alloys with the mass ratio of 65:30. Systematical studies of compatibilizer type, content and its effects on microstructure, mechanical properties, dielectric properties, dielectric properties and dynamic rheological properties have been carried out in this PC/PP alloys. The results demonstrated that all the compatibilizers in this article resulted in an effective improvement of the compatibility of PC/PP alloys, and the self‐made compatibilizer of PPM‐g‐GMA exhibited a significant improvement over the other three compatibilizers in notched izod impact strength, tensile strength, and bending strength. In addition, a relative low dielectric constants and dielectric losses under 2.5 GHz electric field could be obtained with the assistance of POE‐g‐MAH and PPM‐g‐GMA, indicating its possible application in dielectric materials.

IPP/PE Multiblock Copolymers for Plastic Blend Recycling Synthesized by Coordinative Chain Transfer Polymerization

Recycling of blends of widely used plastics is a key challenge of the envisioned circular economy, and thus, protocols permitting the efficient synthesis of effective compatibilizers are highly desirable. We report herein that coordinative chain transfer polymerization permits the efficient one-pot synthesis of multiblock architectures of strictly linear polyethylene or high-density polyethylene (HDPE) and isotactic polypropylene (iPP). Various block copolymers having an iPP backbone and HDPE side chains were synthesized and used to compatibilize HDPE/iPP plastic blends. The synthesized block copolymers differ in their overall molecular weights and have different HDPE side chain lengths and numbers. A block copolymer with a molecular weight of Mp = 33,700 g × mol–1 including 4.5 HDPE side chains with a molecular weight of Mn = 600 g × mol–1 showed the highest efficiency for compatibilizing 30/70 wt % blends of HDPE/iPP with a 5 wt % compatibilizer addition. This block copolymer is also superior to commercially available compatibilizers.

Investigation on the mechanical, thermal, structural and morphological properties of polypropylene/ethylene-vinyl acetate copolymer/graphene oxide nanocomposites: effect of nanofiller surface functionalization and compatibilizers

Rubber toughened PP nanocomposites with desirable thermal properties and tensile strength (TS) found applications in automotive and packaging industries. This article reports on the mechanical, thermal, structural, and morphological properties of polypropylene (PP)/ethylene-vinyl acetate copolymer (EVA) blend reinforced with graphene oxide (GO) and silane-functionalized GO (f-GO). GO was modified with two silanes: γ-glycidoxypropyltrimethoxysilane (GPTMS) and γ-mercaptopropyltrimethoxysilane (MPTMS). The influence of three compatibilizer systems: (PP-g-OH, PP-g-COOH, and PP-g-NH2) on the properties of the composites was also evaluated. The structure and thermal behavior of GO and f-GO were comparatively studied for the first time. The attenuated total reflectance Fourier transform infrared (ATR-FTIR), Raman spectroscopy measurements, and X-ray diffraction (XRD) brought evidence for the successful interactions of silanes with GO. Thermogravimetric analysis (TGA) showed that f-GO exhibited higher thermal stability compared to GO. According to the mechanical analysis, PP/EVA/GPTMS-GO/PP-g-NH2 displayed higher TS and stiffness than the other compatibilized nanocomposites. TGA results indicated that the presence of both f-GO and compatibilizers caused a drastic improvement in the thermal stability. DSC analyses revealed that the addition of nanoparticles led to an increase in PP melting and crystallization temperatures, as well as the degree of crystallinity. XRD patterns revealed the formation of intercalated-delaminated nanocomposites and the promotion of β-phase crystals of PP for the samples containing PP-g-COOH and PP-g-NH2. The scanning electron microscopy (SEM) showed that the addition of compatibilizers drastically reduces the domain size of the EVA particles. All results suggest that GO nanoparticles enhance the mechanical and thermal properties of PP/EVA blend.

Potential of Functionalized Polyolefins in a Sustainable Polymer Economy: Synthetic Strategies and Applications.

Polymers play a crucial role in our modern life as no other material exists that is so versatile, moldable, and lightweight. Consequently, the demand for polymers will continue to grow with the human population, modernization, and technological developments. However, depleted fossil resources, increasing plastic waste production, ocean pollution, and related growing emission of greenhouse gases has led to a change in the way we think about the use of polymers. Although polymers were never designed to be recycled, it is clear that a linear polymers economy is no longer sustainable. The design for recycling and reuse and life-cycle analyses will become increasingly important factors when deciding on which polymer to choose for a certain application. Of all polymers, polyolefins have the lowest life-cycle environmental impact and even outperform renewable polymers. However, polyolefins are chemically inert and reveal a low surface energy. Combining their excellent mechanical properties with the ability to adhere to other materials or create self-assembled or nanostructured materials would widen the application window of polyolefins even more.This Account covers part of our personal account in the field of functionalized polyolefin synthesis and their application development. We start with addressing the challenge of finding suitable catalysts that tolerate nucleophilic functionalities, which tends to poison most electrophilic catalysts even when passivated with, for example, an aluminum alkyl. We argued that lowering of the oxidation state of a titanium-based catalyst might lower the electrophilicity of the metal center. Indeed, this simple approach resulted in an unprecedentedly high tolerance toward aluminum alkyl-passivated alkenols during their copolymerization with ethylene. Interestingly, catalyst deactivation was much less pronounced during the copolymerization of propylene and aluminum-passivated alkenols, clearly demonstrating the protective effect of the methyl branch in the growing polymer. Because the use of randomly functionalized polypropylenes is rather underdeveloped, as compared to the corresponding randomly functionalized polyethylenes, we focused on potential applications of the former material. Atactic or low-crystalline hydroxyl- and carboxylic acid-functionalized propylene-based co- and terpolymers form elastomers with interesting properties that can be influenced by enhancing the hydrogen bonding within the system or by creating ionomers. The polar functionalities cluster together in domains that can host small polar molecules such as, for example, a pH indicator, thus affording useful sensors. The functionalized polyolefins can also be used as precursors for amphiphilic graft copolymers, undergoing self-assembly and therefore being suitable for nanoporous membrane preparation. The graft copolymers also proved to be effective compatibilizers in various polymer blends.

Water boosts reactive toughening of PET

During melt-processing, the molecular weight of poly(ethylene terephthalate) PET, being prone to hydrolytic degradation, decreases proportionally with its initial moisture content. Therefore, to avoid undesired deterioration of the physical and mechanical properties, PET granules or recyclates are generally dried (the residual moisture must be generally lower than 500 ppm) just prior to melt-processing. In this research, in contrast to the general practice, PET granules with increasing moisture content in the range of 30-3520 ppm, as conditioned in a climate chamber, were melt blended with a constant amount (13%) of ethylene-butyl acrylate-glycidyl methacrylate (EBA-GMA) type reactive terpolymer by twin screw extrusion. It was found that moisture boosts the reactive toughening process, and consequently, the notched Izod impact strength increases by up to 600%. Notched impact strength higher than 50 kJ/m2 was reached only by using PET with optimal (1710 ppm) moisture level instead of fully dried granules, as starting material. It is also noteworthy that the tensile strength and stiffness of the blends showed little variation over the examined moisture content range. Scanning electron microscopic analyses show that the size of the dispersed phase decreases continuously with the increasing initial moisture content of PET, which is explained by the increasingly effective interfacial compatibilisation with the terpolymer. Compatibilisation reactions are accelerated by the low-molecular-weight PET chains of increased reactivity that are formed in situ in the presence of moisture during melt-processing. The observed phenomenon can be advantageously utilized for upgrading recycling technology.

Triblock Copolymer Compatibilizers for Enhancing the Mechanical Properties of a Renewable Bio-Polymer.

Poly(lactic acid) (PLA) is an emerging plastic that has insufficient properties (e.g., it is too brittle) for widespread commercial use. Previous research results have shown that the strength and toughness of basalt fiber reinforced PLA composites (PLA/BF) still need to be improved. To address this limitation, this study aimed to obtain an effective compatibilizer for PLA/BF. Melt-blending of poly(butylene adipate-co-terephthalate) (PBAT) with PLA in the presence of 4,4′-methylene diphenyl diisocyanate (MDI: 0.5 wt% of the total resin) afforded PLA/PBAT-MDI triblock copolymers. The triblock copolymers were melt-blended to improve the interfacial adhesion of PLA/BF and thus obtain excellent performance of the PLA-ternary polymers. This work presents the first investigation on the effects of PLA/PBAT-MDI triblock copolymers as compatibilizers for PLA/BF blends. The resultant mechanics, the morphology, interface, crystallinity, and thermal stability of the PLA-bio polymers were comprehensively examined via standard characterization techniques. The crystallinity of the PLA-ternary polymers was as high as 43.6%, 1.44× that of PLA/BF, and 163.5% higher than that of pure PLA. The stored energy of the PLA-ternary polymers reached 20,306.2 MPa, 5.5× than that of PLA/BF, and 18.6× of pure PLA. Moreover, the fatigue life of the PLA-ternary polymers was substantially improved, 5.85× than that of PLA/PBAT-MDI triblock copolymers. Thus, the PLA/PBAT-MDI triblock copolymers are compatibilizers that improve the mechanical properties of PLA/BF.

Compatibilizer effect on optical properties of immiscible PMMA/PS blends

Immıscible polymethyl methacrylate/polystyrene (PMMA/PS) mixtures with various maleic anhydride-styrene-methyl methacrylate (MAStMMA) compatibilizer ratio (0, 2, 4, 6, 8 and 10) % were obtained by solution casting. The spectral results showed that the optical constants such as refractive index (n), extinction coefficient (k) and absorption coefficient increase with increasing terpolymer compatibilizer ratio. On the other hand, the optical energy gap Eg showed an inverse trend to concerning optical constants. The lowest observed energy gap was between 8 and 10 % compatibilizer ratio.

Waste valorization in sustainable engineering materials: Reactive processing of recycled carpets waste with polyamide 6

Waste resources utilization is of utmost importance today to promote sustainable development and minimize pollution. However, it remains a great challenge to reuse, recycle and turn post-consumer wastes into value-added products. Here, we demonstrate a strategy to reprocess post-consumer recycled carpet waste (PCRC) (containing polyamide, polypropylene and other additives and reinforcing agents) with polyamide 6 (PA 6) at different weight ratios through reactive extrusion. The phase adhesion of the PCRC and PA 6 was improved significantly with the aid of poly(ethylene-octene)-grafted-maleic anhydride copolymer (POE-g-MA) and epoxidized styrene-acrylic copolymer (ESAC). Superior notched impact strength and elongation at break were observed when the blends were modified with POE-g-MA and a small amount of chain extender ESAC (0.5–2 phr). Morphological characterization showed a decrease in PCRC droplets size and enhanced its dispersion in the PA 6. FTIR analysis showed an enhancement of interfacial compatibilization between PA 6 and PCRC by the interaction between maleic anhydride of POE-g-MA and epoxy group of ESAC with polyamide functional group through melt mixing. The effective compatibilization of the blends was also evident from thermal and rheological analysis. The results revealed the possible reuse and utilization of recycled carpet for different polymer blends and composites fabrication with high recycled content for various applications.

Ultra-Tough Polylactide/Bromobutyl Rubber-Based Ionomer Blends via Reactive Blending Strategy.

A series of ultra-toughened sustainable blends were prepared from poly(lactic acid) (PLA) and bromobutyl rubber-based ionomers (i-BIIRs) via reactive blending, in which dicumyl peroxide (DCP) and Joncryl®ADR-4440 (ADR) were used as reactive blending additives. The miscibility, phase morphology and mechanical property of the PLA/i-BIIRs blends were thoroughly investigated through DMA, SEM, tensile and impact tests. The influence of different ionic groups and the effects of DCP and ADR on the compatibility between the phases, phase structure and mechanical properties were analyzed. The introduction of the imidazolium-based ionic groups and the reactive agents enable the i-BIIRs play multiple roles as effective compatibilizers and toughening agents, leading to improved interfacial compatibility and high toughness of the blends. The mechanical properties test showed that the PLA/i-BIIRs blends exhibit excellent toughness: impact strength and the elongation at break of AR-OH(30)+AD reached 95 kJ/m2 and 286%, respectively. The impact fracture surface showed the large-scale plastic deformation of the PLA matrix in the blends, resulting in greatly absorbing the impact energy. The results proved that simultaneously applying reactive blend and multiple intermolecular interactions methods is an effective toughening strategy for toughening modification of the PLA blends.

Effects of a new compatibilizer on the mechanical properties of TPU/PEBA blends

In this work, to improve the mechanical properties of thermoplastic polyurethane (TPU), polyether-block-amide elastomer (PEBA) was used to modify it through a blending method. Due to the low compatibility of the two, a polyurethane with one end blocked with an isocyanate group and one end blocked with two epoxy groups was prepared as a compatibilizer, named as E-PU-I. And a series of TPU/PEBA blends with different components were prepared using a torque rheometer, and the effects of E-PU-I on the microstructure, phase interface interaction, rheological properties and mechanical properties of the blends were investigated. It proves that E-PU-I improves the compatibility between TPU and PEBA, resulting in more uniform dispersion of PEBA in TPU and smaller particle size, thus improving the overall performance of the blends. In addition, when the critical E-PU-I content is around 3.2 parts, the mechanical properties of the blends have been significantly improved.

Effects of selective distribution and migration of poly(methyl methacrylate)-grafted nanoclays on the phase behavior of poly(methyl methacrylate)/poly (styrene-co-acrylonitrile) blends

The effect of selective distribution and migration behavior of two kinds of poly (methyl methacrylate)-grafted nanoclays (PMMA- g -clay) on the phase behavior of PMMA/poly (styrene- co -acrylonitrile) (SAN) blends is investigated. The grafting ratios of our two modified nanoclays are similar, but their grafting density and grafted chain lengths are different, resulting in their different initial locations and subsequent migration behaviors in the blend matrix. The PMMA- g -clay(d) nanosheets (NSs) with relatively dense and short chains are always distributed at the interfacial region and further form the percolation networks to block the concentration fluctuation and retard the domain coarsening of blend matrix more remarkably, while the PMMA- g -clay(s) NSs with relatively sparse and long chains are distributed at first in the SAN-rich domains and subsequently move slowly to the interfacial region, resulting in their inhibition of the phase separation for PMMA/SAN blend from retarding SAN chains’ viscous diffusion to their gradual interfacial aggregation for stabilizing the morphology. The variation of storage modulus for three systems in low frequency and long-time regimes are also affected by different selective distributions of two grafted clay NSs in PMMA/SAN blend matrix. • The compatibilization effects of two clay nanosheets grafted with different length and grafting density of PMMA chains were compared. • The two nanosheets have the same thermodynamically stable location but different migration behaviors. • Both the two nanosheets hardly affect the phase coarsening of polymer blend at the early stage of the spinodal decomposition. • The inhibition effects of the two nanosheets are different at intermedium and late stages.

Novel compatibilizers and plasticizers developed from epoxidized and maleinized chia oil in composites based on PLA and chia seed flour

Novel compatibilizers and plasticizers derived from epoxidized chia seed oil (ECO) and maleinized chia seed oil (MCO) have been applied in composites based on poly(lactic acid) (PLA) and 15 wt% chia seed flour (CSF). Results obtained have been compared to conventional silane coupling agent, (3-glycidyloxypropyl) trimethoxysilane (GPS), and a petroleum-based compatibilizer, poly(styrene-co-glycidyl methacrylate) copolymer (Xibond, ®). The compatibilization effect of green composites were assessed by FTIR. The addition of all four compatibilizers improved the ductile mechanical and thermal properties of the composites. The morphology analysis revealed an improvement of interfacial adhesion of the CSF particles into the PLA matrix. In particular, ECO and MCO composites showed a roughness with long filaments in their morphology which plays a crucial role in improving the ductile properties highly. The elongation at break was 10 and 8 times higher using ECO and MCO, respectively, compared to uncompatibilized composite. Moreover, the composites manufactured showed low values (<9%) in the water uptake assay and a negligible compostability delay. The use of novel compatibilizers based on modified vegetable oils could mean an interesting proposal to obtain an entirely environmentally friendly composite with a remarkable ductile property.

Effects of Filler Content and Compatibilizers on the Properties of Low-Density Polyethylene (LDPE)/Thermoplastic Potato Starch (TPS) Blend Composite

Effects of Filler Content and Compatibilizers on the Properties of Low-Density Polyethylene (LDPE)/Thermoplastic Potato Starch (TPS) Blend Composite

Morphology and Properties of Poly(2,6-dimethyl-1,4-phenylene oxide)/Polyamide 11 Hybrid Nanocomposites: Effect of Silica Surface Modification.

Poly(2,6-dimethyl-1,4-phenylene oxide)/polyamide 11 (PPO/PA11 80/20) blend filled with neat (SiO2) or modified silica having amine functional groups (A-SiO2) was melt mixing in a twin-screw extruder. The silica was prepared by the sol–gel process. SEM shows that, with increasing A-SiO2 content from 1 to 5 wt.%, the morphology of PPO/PA11blend changed from droplet matrix to co-continuous with phase inversion. The phase inversion was also observed for 5 wt.% of neat silica, but the droplet-matrix structure was retained. The overall rheological and mechanical properties improvement of the A-SiO2-filled composites in comparison with the unfilled blend and neat silica counterpart was drastic, especially in terms of viscosity and stiffness. A-SiO2 improved PPO and PA11 miscibility and reduced the crystallinity of PA11, without affecting the Tc, owing to the compatibilization effect. On the other hand, neat silica slightly increased the crystallinity of PA11 and decreased the crystallization temperature of PA11 and the glass transition temperature of PPO as a result of its plasticization.

Enhanced properties of polylactide/polyamide 11 blends by reactive compatibilization

AbstractPolylactide (PLA)/polyamide 11 (PA11) blends with 75/25 wt.% composition were prepared using an internal mixer. An epoxy‐based chain extender, Joncryl® ADR 4468, was used for reactive compatibilization of the blends. The effect of the mixing strategy of the chain extender with the blend components on its compatibilization effect and on the morphological, rheological, thermomechanical, and mechanical properties of the blends was determined. Due to more reactivity of the chain extender towards PLA compared to PA11, preparing the blends using the epoxy‐modified PA11 resulted in enhanced compatibilization and a reduction of the number‐average diameter of the dispersed droplets from 1.89 to 0.64 μm in the compatibilized blends. Larger complex viscosity and storage modulus were observed for blends prepared using the modified PA11 compared to blends from the modified PLA, consistent with the observed refinement of the morphology. Strain at break of the compatibilized blends increased to 150% compared to 6% for the neat PLA while maintaining the tensile strength and modulus at 62 MPa and 2 GPa (70 MPa and 2.4 GPa for PLA), respectively. The impact toughness increased from 24 J/m for neat PLA to around 40 J/m in compatibilized blends.

High-performance multifunctional polyvinyl alcohol/starch based active packaging films compatibilized with bioinspired polydopamine nanoparticles

Bioinspired polydopamine (PDA) nanoparticles were synthesized and explored as functional compatibilizers in polyvinyl alcohol/starch (PVA/ST) matrix to develop high-performance multifunctional packaging film. The effect of the addition of PDA on the microstructural, mechanical, thermal, water vapor barrier, ultraviolet (UV)/high-energy blue light (HEBL) blocking, thermal insulating and antioxidant properties of PVA/ST composite films was fully investigated. Results demonstrated that the added PDA nanoparticles were evenly dispersed in the PVA/ST matrix, providing compact and dense nanocomposite films due to their compatibilization effect. Compared with virgin PVA/ST film, the resulting PVA/ST/PDA nanocomposite films exhibited greatly improved tensile strength, toughness, thermal stability, and water vapor barrier ability. Furthermore, the presence of PDA endowed PVA/ST composite film with excellent UV/HEBL blocking, thermal insulating as well as antioxidant functions. Thus, such high-performance multifunctional nanocomposite films hold the potential of protecting food quality against photothermal oxidative deterioration and extend food shelf life.

Investigating effect of compatibilizer on polymer blend filament from post-used styrofoam and polyethylene for fused deposition modelling

This research produced the filament by blending the recycled polystyrene (rPS) from post-used Styrofoam and low-density polyethylene (LDPE). This study used polystyrene-grafted-maleic anhydride (PS-g-MA) as a compatibilizer to the rPS/LDPE blend. The formulated filaments were printed into specimens using a FDM printer. The visual inspection results showed that the printed specimens displayed better adhesion as the printing temperature and extrusion rate percentage increased. The addition of PS-g-MA also enhanced the adhesion of the printed layers. In terms of tensile properties, adoption of PS-g-MA also significantly improved the tensile strength and tensile modulus of the printed specimens. Furthermore, the addition of PS-g-MA increased the degree of crystallinity but it has shown no significant effect on the melting temperature. In addition, compatibilized rPS/LDPE blend samples possessed higher onset thermal degradation temperatures than the uncompatibilized rPS/LDPE blend sample, where higher onset thermal degradation temperature indicated that the material has better thermal stability. Overall, PS-g-MA was an effective compatibilizer to the immiscible rPS/LDPE blend filament where improvements of overall material properties and print quality can be observed, and especially with 5 wt% of PS-g-MA compatibilizer content, the tensile, thermal properties and print quality were improved the most.

Rheological behavior of poly(propylene) reinforced with graphene nanoplatelets for injection molding

AbstractPoly(propylene) (PP)‐based graphene nanoplatelets (GnPs) nanocomposites are processed by a melt blending technique. To obtain more knowledge about the rheological behavior of nanocomposites for injection molding, the rheological characterization of nanocomposites is performed using a double capillary rheometer over a shear rate range from 10 to 6000 s−1. The influence of processing temperature (170, 180, and 190°C) is evaluated. To improve the interaction between PP and GnPs, maleic anhydride (MA) is applied as a compatibilizer. The viscosity master curves are fitted to the Cross‐WLF model. In relation to neat PP, the presence of GnPs promote a viscosity decrease. The nanocomposites containing MA exhibit a higher viscosity than the non‐compatibilized counterparts, suggesting adhesion improvement between PP and GnPs. In addition to the MA compatibilizer effect, the results show that its presence could act as a plasticizer/lubricant in the PP matrix. The morphology characterization of nanocomposites suggests that in addition to improving the adhesion between PP and GnPs, the MA presence also improved the GnPs dispersion in the PP matrix. The presence of GnPs and MA can affect the Newtonian behavior of the PP matrix. All studied samples reveal thermo‐rheological simplicity and pseudo‐plastic behavior.

Fusion Bonding Possibility for Incompatible Polymers by the Novel Ultrasonic Welding Technology: Effect of Interfacial Compatibilization.

Fusion bonding for polymers has been successfully welded for the same and dissimilar materials. However, it is difficult to bond incompatible polymers due to poor interfacial adhesion. Usually, interfacial compatibilization can resolve this problem. According to the mechanism, an interlayer solder sheet (ISS) consisting of maleic anhydride-functionalized polypropylene (PP-g-MAH) and polyamide6 (PA6) was introduced into the ultrasonic welding (USW) device. In this way, it successfully realized the weldability between PP and PA6. The welding strength of PP–PA6 reached 22.3 MPa, about 84% welding strength for the PP body and 63% tensile strength for PP. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) showed the formation of PP-g-PA6 copolymer in blends. This copolymer played the role of an emulsifier, which enhanced the interfacial adhesion between PP and PA6 in two phases, leading to micron-scale homogeneity. In the USW process, the copolymer could act as a bridge between PP and PA6 molecular chains to realize the fusion bonding of incompatible polymers. Finally, we proposed the fusion bonding model for PP–PA6 interfaces.