The effect of hybrid nanoparticle with silica sol as the supporter on the crystallization behavior and mechanical properties of isotactic polypropylene

2015 ◽  
Vol 35 (6) ◽  
pp. 565-573 ◽  
Author(s):  
Juan Li ◽  
Shuhao Qin ◽  
Wentao He ◽  
Yushu Xiang ◽  
Qin Zhang ◽  
...  

Abstract Colloidal dispersions of hybrid nanoparticles with silica sol as the supporter (PKSol) were prepared by supporting aromatic phosphate on silica sol via a chemical action with γ-aminopropyltrimethylsilane (KH550) as a linker in wet process for the first time. Dynamic light scattering (DLS) demonstrated that hybrid nanoparticles with an average size of about 200 nm were formed and transmission electron microscopy (TEM) confirmed the presence of the ultrafine silica sols within the hybrid particles, which exhibited “currant-bun” particle morphologies, rather than typical “core-shell” structures for most polymer-encapsulated silica particles. Compared to aromatic phosphate alone and silane-modified silica sol, the effect of PKSol on the crystallization behavior and mechanical properties of isotactic polypropylene (iPP) was investigated using a polarized optical microscope (POM) and differential scanning calorimetry (DSC). The results demonstrated that PKSol showed superior nucleating ability on iPP than the other two. After adding 0.2 wt% PKSol, the crystallization peak temperature of iPP increased from 116.35°C to 120.81°C and the crystallinity increased from 39.6% to 50%. Correspondingly, the haze decreased from 37.6% to 23.3% and mechanical properties were improved.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


e-Polymers ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 1-11
Author(s):  
Wei Zhang ◽  
Qingyin Wang ◽  
Gongying Wang ◽  
Shaoying Liu

Abstract The effects of isothermal crystallization temperature/time on mechanical properties of bio-based polyester poly(ethylene 2,5-furandicarboxylate) (PEF) were investigated. The intrinsic viscosity, crystallization properties, thermal properties, and microstructure of PEF were characterized using ubbelohde viscometer, X-ray diffraction, polarizing optical microscope, differential scanning calorimetry, and scanning electron microscopy. The PEF sample isothermal crystallized at various temperatures for various times was denoted as PEF-T-t. The results showed that the isothermal crystallization temperature affected the mechanical properties of PEF-T-30 by simultaneously affecting its crystallization properties and intrinsic viscosity. The isothermal crystallization time only affected the crystallization properties of PEF-110-t. The crystallinity of PEF-110-40 was 17.1%. With small crystal size, poor regularity, and α′-crystal, PEF-110-40 can absorb the energy generated in the tensile process to the maximum extent. Therefore, the best mechanical properties can be obtained for PEF-110-40 with the tensile strength of 43.55 MPa, the tensile modulus of 1,296 MPa, and the elongation at a break of 13.36%.


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Yanyan Wei ◽  
Chengzhong Zong ◽  
Fufang Wang

AbstractVinyl polymer/polyurethane hybrid latex particles with various compositions were successfully prepared via emulsion polymerization of vinyl monomer in the presence of self-emulsified polyurethane dispersion without using any surfactant. Studies were carried out on polymerization kinetics, characterization of the hybrid particles and the physical properties of nano-sized vinyl polymer particle/thermoplastic polyurethane blends. It was found that the maximum content of vinyl polymer in polyurethane hybrid particles was up to 80 percent and all of the vinyl polymer/polyurethane hybrid particles were less than 120 nm. Infrared spectroscopy, thermal gravimetric analysis and differential scanning calorimetry analysis indicated the influence of vinyl polymer on the polyurethane hybrid particles. With the polyurethane shells outside and, therefore, good compatibility with polyurethane matrix, the hybrid particles can be easily blended into polyurethane matrix. Some unusual changes of dynamic mechanical properties in the low temperature region were found in the blends of hybrid particles and thermoplastic polyurethane. With the addition of only 3%, the mechanical properties of these blends did not show a significant change. This study provided a new method to prepare hybrid particles in the absence of surfactant and made an attempt on application of vinyl polymer/polyurethane hybrid particles in the blending modification


2019 ◽  
Vol 814 ◽  
pp. 96-101
Author(s):  
Kun Yan Wang

Poly (trimethylene terephthalate) (PTT)/functionalized graphene oxide (fGO) nanocomposites were prepared by melt compounding. The crystalline morphology and crystallization behavior of PTT/fGO with different amounts of fGO were investigated by differential scanning calorimetry (DSC) and polarizing optical microscope (POM). The results show that the crystallization peak shifts to higher temperature after adding fGO, indicating that fGO have a nucleating effect on PTT. The crystallization temperature of nanocomposites increases with increasing content of fGO. The XRD pattern of PTT/fGO nanocomposites almost no change that indicated the degree of crystallinity of the PTT matrix remained unaffected by the addition of fGO. The nanocomposite revealed integrated Maltese crossed spherulitic morphologies. When adding 1% fGO to the PTT, big-sized PTT spherulites occurred and small-sized PTT spherulites were formed around the big-sized PTT spherulites which indicated that the mechanism of nucleation is changed.


2014 ◽  
Vol 941-944 ◽  
pp. 1253-1256
Author(s):  
Kun Yan Wang

Polypropylene (PP)/Maleic anhydride grafted poly (ethylene-octene) (POEg) were prepared by melt blending method. The crystallization behavior and crystal morphology were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarzing optical microscope (POM). Differential scanning colorimetry (DSC) experiments showed that the melting point and crystallization point decreased when POEg added to the blend. XRD results show that the POEg not change the crystal structure in the blends but only decrease the intensity of the diffraction peak. The spherulitic structure could also observed when added POEg to the matix of PP, but the shape of the spherulites distorted.


2021 ◽  
Vol 36 (5) ◽  
pp. 545-556
Author(s):  
A. Hamza ◽  
R. K. Arya ◽  
A. D. Palsodkar ◽  
G. R. Bhadu ◽  
S. J. A. Rizvi

Abstract Isotactic polypropylene (iPP) was nucleated in-situ with calcium pimelate during melt compounding. Calcium pimelate is a highly effective β-nucleator for isotactic polypropylene (iPP). The β-nucleated iPP was characterized by wide angle x-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for its crystallinity and crystal structure. In addition, the injection-molded samples were tested for thermo-mechanical properties. It is found that very low quantity (< 0.1 wt. %) of β-nucleator is required to produce sufficiently high β-crystal fraction (Kβ) in isotactic polypropylene. β-nucleated iPP shows increment of 11 to 14 °C in its heat deflection temperature (HDT). It was also observed that slow cooling rate of β-nucleated iPP promotes the formation of β-crystals and that tensile stretching leads to complete transformation of β crystals into a-crystals at room temperature. It was also revealed that the presence of maleic anhydride grafted polypropylene (PP-g-MA), a well-known coupling agent (or compatibilizer), may reduce the (Kβ) value to a marginal extent. It was also observed that the thermo-mechanical properties were not much affected by the presence of PP-g-MA. Therefore, calcium pimelate may be used as β-nucleator in case of neat as well as reinforced polypropylene containing maleic anhydride as coupling agent.


RSC Advances ◽  
2017 ◽  
Vol 7 (67) ◽  
pp. 42113-42122 ◽  
Author(s):  
Bo Wang ◽  
Hai-Rong Zhang ◽  
Chao Huang ◽  
Lian Xiong ◽  
Jun Luo ◽  
...  

Bacterial cellulose (BC) has great potential to be used as a new filler in reinforced isotactic polypropylene (iPP) due to its characteristics of high crystallinity, biodegradability and efficient mechanical properties.


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