scholarly journals Effects of zinc acetate and cucurbit[6]uril on PP composites: crystallization behavior, foaming performance and mechanical properties

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 491-499 ◽  
Author(s):  
Yuhui Zhou ◽  
Li He ◽  
Wei Gong

AbstractIn this study, polypropylene (PP) foams were prepared with 1.0 wt% of cucurbit[6]uril (Q[6]), zinc acetate (Zn(Ac)2), Zn@Q[6] (a supramolecular compound synthesized from Q[6] and Zn(Ac)2), or a mixture of Zn(Ac)2 and Q[6] (weight ratio of 1:1) through injection molding in the presence of a chemical blowing agent, azodicarbonamide. The effect of the additions on the crystallization behavior and foaming performance of PP and the mechanical characterizations of the foaming samples were determined. The results showed that the additions can change the crystallization type from homogeneous to heterogeneous, increase the crystallization rate and shrink the size but increase the density of spherulites. Among the additions, Q[6] most significantly altered the crystallization properties. Scanning electron microscopy (SEM) images revealed that the PP foaming performance can be improved by Zn(Ac)2 addition at a lower temperature (175°C); however, further increasing the temperature had an undesirable effect. Q[6] exhibited the optimum foaming improvement effect on PP in a wide temperature range (175–195°C). Adding nanoparticles also enhanced the tensile properties, flexural strength and impact strength of foaming PP at low temperatures. However, with increasing temperature, the poor cell structure demonstrated undesirable effects in terms of tensile strength, flexural strength and impact strength.

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3871-3885
Author(s):  
Amir Lashghari ◽  
Ehsan Ganjavi

This study investigated the effect of pressurized temperature on the thermal, mechanical, and morphological properties of nanocomposites made from recycled polyethylene with the weight ratio of 50%. Nanosilica was applied at 3 levels (0, 4, 8 %) and wood flour had a weight ratio of 50%. High-density polyethylene (HDPE) went through multiple procedures. It was found that by increasing the nanosilica content, the tensile and flexural strength properties, the residual ash content, and the thermal stability increased along with a reduction in the tensile and flexural modulus and impact resistance. As the temperature increased, the tensile and flexural strength and modulus and the impact resistance decreased. Scanning electron microscopy (SEM) images revealed that samples with 8% nanosilica showed different polymerization than the wood flour particles.


2014 ◽  
Vol 1025-1026 ◽  
pp. 215-220 ◽  
Author(s):  
Sasirada Weerasunthorn ◽  
Pranut Potiyaraj

Fumed silica particles (SiO2) were directly added into poly (butylene succinate) (PBS) by melt mixing process. The effects of amount of fumed silica particles on mechanical properties of PBS/fumed silica composites, those are tensile strength, tensile modulus, impact strength as well as flexural strength, were investigated. It was found that the mechanical properties decreased with increasing fumed silica loading (0-3 wt%). In order to increase polymer-filler interaction, fumed silica was treated with 3-glycidyloxypropyl trimethoxysilane (GPMS), and its structure was analyzed by FT-IR spectrophotometry. The PBS/modified was found to possess better tensile strength, tensile modulus, impact strength and flexural strength that those of PBS/fumed silica composites.


2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.


2008 ◽  
Vol 173 (10) ◽  
pp. 1023-1030 ◽  
Author(s):  
Denis Vojvodic ◽  
Franjo Matejicek ◽  
Ante Loncar ◽  
Domagoj Zabarovic ◽  
Dragutin Komar ◽  
...  

Author(s):  
Zahid Iqbal Khan ◽  
Zurina Binti Mohamad ◽  
Abdul Razak Bin Rahmat ◽  
Unsia Habib ◽  
Nur Amira Sahirah Binti Abdullah

This work explores a novel blend of recycled polyethylene terephthalate/polyamide 11 (rPET/PA11). The blend of rPET/PA11 was introduced to enhance the mechanical properties of rPET at various ratios. The work’s main advantage was to utilize rPET in thermoplastic form for various applications. Three different ratios, i.e. 10, 20 and 30 wt.% of PA11 blend samples, were prepared using a twin-screw extruder and injection moulding machine. The mechanical properties were examined in terms of tensile, flexural and impact strength. The tensile strength of rPET was improved more than 50%, while the increase in tensile strain was observed 42.5% with the addition of 20 wt.% of PA11. The improved properties of the blend were also confirmed by the flexural strength of the blends. The flexural strength was increased from 27.9 MPa to 48 MPa with the addition of 30 wt.% PA11. The flexural strain of rPET was found to be 1.1%. However, with the addition of 10, 20 and 30 wt.% of PA11, the flexural strain was noticed as 1.7, 2.1, and 3.9% respectively. The impact strength of rPET/PA11 at 20 wt.% PA11 was upsurged from 110.53 to 147.12 J/m. Scanning electron microscopy analysis revealed a dispersed PA11 domain in a continuous rPET matrix morphology of the blends. This work practical implication would lead to utilization of rPET in automobile, packaging, and various industries.


2021 ◽  
pp. 096739112110093
Author(s):  
RM Abhilash ◽  
GS Venkatesh ◽  
Shakti Singh Chauhan

Reinforcing thermoplastic polymers with natural fibres tends to improve tensile and flexural strength but adversely affect elongation and impact strength. This limits the application of such composites where toughness is a major criterion. In the present work, bamboo fibre reinforced polypropylene (PP) composites were prepared with bamboo fibre content varying from 30% to 50% with improved impact resistance. Homopolymer and copolymer PP were used as the matrix polymer and an elastomer was used (10% by wt.) as an additive in the formulation. Copolymer based composites exhibited superior elongation and impact strength as compared to homopolymer based composites. The adverse impact of elastomer on tensile and flexural strength was more pronounced in homopolymer based composites. The study suggested that the properties of the bamboo composites can be tailored to suit different applications by varying reinforcement and elastomer percentage.


2019 ◽  
Vol 39 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Bingxiao Liu ◽  
Guosheng Hu ◽  
Jingting Zhang ◽  
Zhongqiang Wang

AbstractStudy of the crystallization kinetics is particularly necessary for the analysis and design of processing operations, especially the non-isothermal crystallization behavior, which is due to the fact that most practical processing techniques are carried out under non-isothermal conditions. The non-isothermal crystallization behaviors of polyamide 6 (PA6) and PA6/high-density polyethylene/maleic anhydride/2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (PA6/HDPE/MAH/L-101) composites were investigated by differential scanning calorimetry (DSC). The crystallization kinetics under non-isothermal condition was analyzed by the Jeziorny and Mo equations, and the activation energy was determined by the Kissinger and Takhor methods. The crystal structure and morphology were analyzed by wide-angle X-ray diffraction (WXRD) and polarized optical microscopy (POM). The results indicate that PA6/HDPE/MAH/L-101 has higher crystallization temperature and crystallization rate, which is explained as due to its heterogeneous nuclei.


RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37139-37147 ◽  
Author(s):  
Diran Wang ◽  
Faliang Luo ◽  
Zhiyuan Shen ◽  
Xuejian Wu ◽  
Yaping Qi

In order to overcome low crystallization rate of PET, HPN-68L was selected to replace the special nucleate agent of PET to improve PET crystallization for its carboxylate anion structure which usually showed high induced nucleation ability for PET.


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2981
Author(s):  
Bianka Nagy ◽  
Norbert Miskolczi ◽  
Zoltán Eller

The aim of this research was to increase the compatibility between PLA and starch with vegetable oil-based additives. Based on tensile results, it can be stated, that Charpy impact strength could be improved for 70/30 and 60/40 blends in both unconditioned and conditioned cases, regardless of vegetable oil, while no advantageous change in impact strength was obtained with PLA-g-MA. Considering sample with the highest starch concentration (50%), the flexural modulus was improved by using sunflower oil-based additive, Charpy impact strength and elongation at break was increased using rapeseed oil-based additive in both conditioned and unconditioned cases. SEM images confirmed the improvement of compatibility between components.


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