This research provides an effective approach to synthesize a hyperbranched star polymeric ionic liquid (HBPS-(PVIMBr)x) with a hyperbranched polystyrene core and poly(1-butyl-3-vinylimidazolium bromide) arms via a combination of atom transfer radical self-condensing vinyl polymerization (ATR-SCVP) and RAFT polymerization. The synthesis process ensures good structural controllability and consistency that all of the arms of the star polymers are ionized. The obtained star polymeric ionic liquid shows good thermal stability with initial thermal decomposition temperatures above 290 °C. Moreover, after anion exchange, the TFSI− anion based hyperbranched star polymeric ionic liquid (HBPS-(PVIMTFSI)x) is used as the all-solid polymer electrolyte for lithium-ion batteries. The electrolytes (HBPS-(PVIMTFSI)x/LiTFSI) fabricated by the solution casting method exhibit a high room temperature ionic conductivity (4.76 × 10−5 S cm−1, the quantitative ratio of LiTFSI to the polymer matrix is 40%), a wide electrochemical window (4.9 V) and great interfacial compatibility.

Here, two type of composite star polymer electrolytes enhanced by carbon nano-tube (CNT) or fullerene (C60) prepared through a solution-casting technique are investigated. The as-prepared free-standing carbon nano-composite polymer electrolyte membranes exhibit excellent comprehensive performances including high thermal stability (initial thermal degradation temperatures about 383 °C) and good electrochemical properties. However, different carbon nanomaterials bring different influence on electrochemical performances of composite polymer electrolytes. The ionic conductivity of carbon nanotube composite polymer electrolyte (HBPS-(PMMA-b-PPEGMA)30/CNT/LiTFSI) is higher than that of fullerene composite polymer electrolyte. The highest ionic conductivity of HBPS-(PMMA-b-PPEGMA)30/CNT/LiTFSI electrolyte can reach 1.06 × 10−5 S cm−1 at 30 °C and lithium-ion transference number reaches 0.52. In addition, two types of carbon nano-composite star polymer electrolytes both exhibit wide electrochemical window with oxidation potential above 5.2 V, good interfacial stability and interfacial compatibility. Moreover, assembled Li/LiFePO4 cells based on HBPS-(PMMA-b-PPEGMA)30/CNT/LiTFSI electrolytes possess good specific capacity with the highest value of 133 mAhh g−1, while the cells based on HBPS-(PMMA-b-PPEGMA)30/C60/LiTFSI electrolytes show a great cycle stability.

•A new hyperbranched multi-arm star polymer was successfully synthesized.•The star polymer electrolyte has good thermal stability and forming-film property.•The ion conductivity electrolyte can reach 8.3 × 10−5 S cm−1 at room temperature.•The star polymer electrolyte has wide electrochemical windows of 4.7 V.A new hyperbranched multi-arm star polymer with hyperbranched polystyrene (HBPS) as core and polymethyl methacrylate-block-poly(ethylene glycol) methyl ether methacrylate(PMMA-b-PPEGMA) as arms was firstly synthesized by atom transfer radical polymerization. The obtained hyperbranched multi-arm star polymer (HBPS-(PMMA-b-PPEGMA)x) exhibited good thermal stability with a thermal decomposition temperature of 372 °C. The transparent, free-standing, flexible polymer electrolyte film of the blending of HBPS-(PMMA-b-PPEGMA)x and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) was successfully fabricated by a solution casting method. The ionic conductivity of the hyperbranched star polymer electrolyte with a molar ratio of [EO]/[Li] of 30 could reach 8.3 × 10−5 S cm−1 at 30 °C (with the content of PPEGMA of 83.7%), and 2.0 × 10−4 S cm−1 at 80 °C (with the content of PPEGMA of 51.6%). The effect of the concentration of lithium salts on ionic conductivity was also investigated. The obtained all-solid-state polymer electrolyte possessed a wide electrochemical stability window of 4.7 V (vs. Li+/Li), and a lithium-ion transference number (tLi+) up to 0.31. The interfacial impedance of the fabricated Li│polymer electrolyte│Li symmetric cell based on hyperbranched star multi-arm polymer electrolyte exhibited good interfacial compatibility between all-solid-state polymer electrolyte and electrodes. The excellent properties of the hyperbranched star polymer electrolyte made it attractive as solid-state polymer electrolyte for lithium-ion batteries.

Five salicylates with different sizes of hydrocarbon substituents were firstly synthesized and employed as ecofriendly internal donors of the Ziegler–Natta catalyst for propylene polymerization. The influences of these salicylates and traditional, industrial, internal donor diisobutyl phthalates on the microstructure of polypropylene and active center in a Ziegler–Natta catalyst were studied. It was found that the catalyst activities of the catalysts containing salicylate internal donors with a proper volume were higher than the catalysts containing diisobutyl phthalate internal donors. GPC results showed that the molecular weights of polypropylene prepared by salicylate internal donors were lower than those prepared by diisobutyl phthalate, which indicated that the polypropylene chains produced by salicylate internal donors were easier to transfer than those prepared by diisobutyl phthalate internal donors. Deconvolution of the GPC curves exhibited that as the volume of the salicylate internal donor increased some of the active centers for low molecular weight transferred into the active centers for high molecular weight. The results of 13C-NMR and SSA both suggested that a salicylate internal donor with an appropriate catalyst size volume was beneficial for increasing the isotactic sequence length, isotacticity index and regular triads “mm” of polypropylene. However, further increasing the volume of the salicylate internal donor in a catalyst would lead to the polypropylene chain containing more stereo-defects. Moreover, the active centers with different stereospecificity parameters, piso, in the catalyst could explain the trend of stereo-defects in polypropylene chains when different internal donors were used. In addition, it was found that the isotactic sequence length and isotacticity index of polypropylene prepared by isobutyl 2-benzyloxy-3,5-isopropyl benzoate were close to that produced by a diisobutyl phthalate internal donor. Moreover, the lamella thickness distribution of the polypropylene produced by a salicylate internal donor was broad, which might have potential application for expanded polypropylene materials.

Alkoxysilane compounds R1R2Si(OMe)2 were used as external donors in 1-butene polymerization with MgCl2-supported Ziegler–Natta catalysts. The structure of the prepared iPB was characterized by 13C NMR and GPC. The thermal properties of poly(1-butene) (iPB) were studied by DSC. The crystallization behavior and sequence length distribution of poly(1-butene) were investigated using successive self-nucleation and annealing (SSA) thermal fractionation technology. The SSA results indicated that steric hindrance of an external donor has more influence on the properties of iPB, as each melting point peak and the enthalpy of fusion of iPB gradually increased with an increase in steric hindrance of the external donor. Considering all properties, cyclopentyl-isopropyl-dimethoxysilane had an advantage compared to other external donors in the polymerization of 1-butene.

A novel type of spherical nano Ziegler–Natta catalyst was prepared by loading TiCl4 on nanosized magnesium chloride support for propylene polymerization to form nanosized spherical polypropylene (PP) particles. Polyvinylpyrrolidone (PVP), a common macromolecular surfactant, was used to ensure sphericity and inhibit aggregation of the nanosized particles. The morphology of the support (60 nm), catalyst (80 nm), and PP particles (500 nm) were spherical, and the size distribution is uniform which is confirmed by scanning electron microscopy (SEM) and transmission electron microscope (TEM), respectively. The laser granulometer results showed that the size of the prepared PP particles was in the range of 10–110 um, and the average diameter was 36 um, which had potential application in 3D printing. In addition, the obtained polypropylene had low bulk density (0.170 g/mL).

A low molecular weight aliphatic amide, N, N′-ethylenebis (12-hydroxystearamide) (EBH), was selected to tailor the crystallization behavior of poly (l-lactide) (PLLA). The effect of EBH on the crystallization kinetics, fine crystalline structure, and molecular mobility of PLLA has been systematically investigated. It has been found that the crystallizability of PLLA, including crystallization rate and crystallinity, can be promoted significantly by the addition of only 1 wt% EBH. Both the nucleation density and linear growth rate of spherulites have been improved, which together contributed to the decrease of overall crystallization time. The long period and lamellar thickness of PLLA crystals increased gradually with the isothermal crystallization temperature, whereas they were less influenced by the incorporation of EBH. Dynamic mechanical analysis proved that the mobility of PLLA chains was also increased in the presence of EBH. The accelerating effect of EBH on both the nucleation and molecular mobility of PLLA was supposed to be the hydrogen-bonding interaction between the hydroxyl groups in EBH and carboxyl groups in PLLA.

Hyperbranched poly(glycidol) containing hydroxyl groups was firstly synthesized via anionic polymerization and then reacted with 2-bromoisobutyl bromide to form macroinitiator HPG-Br. Finally, a hyperbranched star polymer (HPG-PPEGMA) was successfully prepared by atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate using HPG-Br as macroinitiator. The structures and properties of the obtained polymers were characterized by 1H NMR, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The ionic conductivity of the polymer electrolytes composed of HPG-PPEGMA and lithium bis(trifluoromethanesulfonimide) (LiTFSI) was investigated via electrochemical impedance spectroscopy. The results showed that the room temperature ionic conductivity of the prepared hyperbranched star polymer electrolytes had a higher ionic conductivity. When [EO]/[Li] was 20, the ionic conductivity of the hyperbranched star polymer electrolyte was up to 1 × 10−4 Scm−1 at 30 °C. The onset decomposition temperature of the hyperbranched star polyether could reach 374 °C, indicating that the hyperbranched star polymer had a good thermal stability. The XRD results showed that the structure of the hyperbranched star polymer was beneficial to improve the ionic conductivity due to possessing a low degree of crystallinity.

Hyperbranched star polymer HBPS-(PPEGMA)x was synthesized by atom transfer radical polymerization (ATRP) using hyperbranched polystyrene (HBPS) as macroinitiator and poly(ethylene glycol) methyl ether methacrylate (PEGMA) as monomer. The structure of the prepared hyperbranched star polymer was characterized by 1H NMR, ATR-FTIR, and GPC. Polymer electrolytes based on HBPS-(PPEGMA)x, lithium salt, and/or nano-TiO2 were prepared. The influences of lithium salt concentration and type, nano-TiO2 content, and size on ionic conductivity of the obtained polymer electrolytes were investigated. The results showed that the low crystallinity of the prepared polymer electrolyte was caused by the interaction between lithium salt and polymer. The addition of TiO2 into HBPS-(PPEGMA)x/LiTFSI improved the ionic conductivity at low temperature. The prepared composite polymer electrolyte showed the highest ionic conductivity of 9 × 10−5 S cm−1 at 30 °C when the content of TiO2 was 15 wt% and the size of TiO2 was 20 nm.

•A series of novel copolymers were synthesized via cationic polymerization.•The ionic conductivity of polymer electrolytes has large improvement.•These polymers and PEO matrix have good compatibility.•The good compatibility can evidently promote ion migration.A series of novel branched copolyethers, poly((1,3-dioxlolane)-co-((2-(2-methoxylethoxyl)methyl)oxirane)) (P(DXL-co-MEMO)) and poly((1,3-dioxlolane)-co-((2-(2-(2-methoxylethoxyl)ethoxyl)methyl)oxirane)) (P(DXL-co-ME2MO)), were synthesized via cationic polymerization, and the structures of these copolymers were characterized by 1H NMR and GPC. Ionic conductivities of copolyether/lithium bis(trifluoromethanesulphonyl)imide (LiTFSI), polyethylene oxide (PEO)/LiTFSI and PEO/copolyether/LiTFSI were investigated via electrochemical impedance spectroscopy. The results showed that the ionic conductivity of the P(DXL-co-MEMO)/LiTFSI polymer electrolyte was higher than that of the P(DXL-co-ME2MO)/LiTFSI polymer electrolyte, and the room temperature ionic conductivity of the P(DXL-co-MEMO)/LiTFSI polymer electrolyte was up to 2.2 × 10− 4 S cm− 1. Compared with the PEO/LiTFSI polymer electrolyte, the ionic conductivities of the PEO/copolyether/LiTFSI composite polymer electrolytes had a great improvement, but their thermal stabilities did not obviously reduce.

Hyperbranched poly(glycidol) (HPG) containing hydroxyl groups is firstly synthesized via anionic polymerization, and then reacts with thionyl chloride to form chlorine end-terminated hyperbranched poly(glycidol) (HPG-Cl). Different ionic liquid polymers are synthesized from the reaction of HPG-Cl with N-methylimidazole and then anion exchange with hexafluorophosphoric acid and sodium tetrafluoroborate. The structure and properties of the obtained ionic liquid polymers are characterized by 1H NMR, ATR-FTIR, DSC and TGA, respectively. Ionic conductivity of the polymer electrolytes composed of ionic liquid polymer and lithium bis(trifluoromethanesulfonimide) (LITFSI) is investigated by electrochemical impedance spectroscopy. The results show that the ionic conductivity of the prepared ionic liquid polymer electrolyte can reach 3.5 × 10−4 Scm−1 at 30 °C when the weight ratio of ionic liquid polymer ([HPG-MeIm]BF4) to lithium salt (LiTFSI) is 4.5.

The new aminosilane compounds including Dimorpholindimethoxysilane (Donor-Pm), Di (1-methylpiperazine) dimethoxysilane (Donor-Pz) and Di (isopropylpiperazine) dimethoxysilane (Donor-Pi) were firstly synthesized and then employed as external donors for propylene polymerization with MgCl2-supported Ziegler-Natta catalyst, compared with dipiperidine dimethoxysilane (Donor-Py). The effects of the aminosilane external donors on the catalytic activity, hydrogen response, and molecular weight distribution, crystalline ability, thermal property, isotactic sequence length, isotactic sequence distribution of polypropylene were studied by differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and self-nucleation and annealing (SSA), respectively. It was found that these new aminosilane compounds were conducive to improving the isotacticity of polypropylene and the catalytic activity. The GPC results showed that the molecular weight distribution of polypropylene prepared respectively by Donor-Pz or Donor-Pi with two N atoms on each amino substituent group was broader more than 8.0, especially for Donor-Pi with the large alkyl-substituted group on each nitrogen atom, the molecular weight distribution of polypropylene was about 11.2, which was much broader than that of industrial polypropylene about 4 ~ 5. The DSC results indicated that the degrees of crystallinity of polypropylene prepared by the aminosilane external donors were higher, and the crystallization ability of polypropylene prepared by Donor-Pi was lower but closed to that of polypropylene prepared by Donor-Py. The SSA results indicated Donor-Py and Donor-Pi were conducive to improving the relative contents of the highest isotactic component of polypropylene, and the lamellae thicknesses results showed the sequence length of polypropylene prepared by Donor-Py and Donor-Pi were longer, and the isotactic sequence distribution of polypropylene prepared by Donor-Py and Donor-Pi were broader. The study results showed that the new aminosilane donor Donor-Pi was conducive to improving the stereo-regularity of polypropylene, especially revealing that it was a simple and an effective method to synthesize broad molecular weight distribution of polypropylene by using appropriate aminosilane external donor for propylene polymerization.

The stereo-defects distribution of polypropylene of the two industry biaxially oriented polypropylene (BOPP) samples T28FE and F28SO with different processing properties was studied through successive self-nucleation and annealing (SSA) technique. It was found that there were more medium isotactic components in sample F28SO, and the isotactic sequence length of polypropylene of sample F28SO was shorter and the isotactic sequence length distribution of polypropylene of sample F28SO was broader, which could be processed well at high-speed orientation during the processing of BOPP films. This result indicates that the isotactic sequence length distribution of polypropylene is related to the processing speed during preparing BOPP films, and the stereo-defects distribution of polypropylene has an important influence on its processing ability.

As the external donor in Ziegler-Natta catalysts have an important influence on the stereo-defects distribution of polypropylene, the effects of the mixed external donors (the mixture of Donor-C (cyclohexylmethyldimethoxysilane) and Donor-N (n-propyltriethoxysilane) ) on the isotactic sequence length and its distribution of polypropylene prepared by Ziegler-Natta catalyst through propylene bulk polymerization were studied through the Successive self-nucleating and annealing (SSA) and 13C-NMR techniques. The SSA results showed that the relative contents of the highest isotactic component and the lamellar thickness in the polypropylene chain gradually increased with the increase of the relative component of Donor-C in the C/N mixed external donors, indicating the isotactic sequence length of polypropylene got longer, and the lamellar thickness distribution of polypropylene became broader, revealing the isotactic sequence length distribution of polypropylene got broader. In addition, the 13C-NMR results showed that the average meso isotactic sequence length (MSL) of polypropylene gradually increased with the increase of the content of Donor-C in the C/N mixed external donors, which was in good coincident with the results calculated from SSA, showing a good correspondence between the SSA and 13C-NMR techniques.