Rheological properties and dynamic thermal stability of PVC / La L 2 / Ca‐Zn composite stabilizer

Author(s):  
Deling Li ◽  
Congcong Luo ◽  
Bing Yao ◽  
Yue Ding ◽  
Jizhen Ren
2020 ◽  
Vol 40 (9) ◽  
pp. 727-735
Author(s):  
Rudinei Fiorio ◽  
Chaitanya Danda ◽  
João Maia

AbstractIn this study, thermoplastic polyurethanes (TPUs) containing trisilanol isooctyl polyhedral oligomeric silsesquioxane (POSS), a reactive nanofiller, were synthesized and characterized rheologically and morphologically, and the effects of POSS content on the melt thermal stability of the TPUs are investigated. Samples containing 0, 0.23, 0.57, 1.14, and 2.23% (w/w) POSS were synthesized by reactive extrusion and characterized by Fourier transform infrared spectroscopy (FTIR), oscillatory and extensional rheometry, atomic force microscopy (AFM), and small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). The rheological properties of molten TPU are time-dependent and the melt thermal stability of the TPU is maximal at 1.14% of POSS. The addition of 0.23 and 0.57% POSS promotes strain-hardening at low extensional strain rates (0.01 and 0.10 s−1), not affecting the extensional characteristics at higher strain rates. The addition of increasing amounts of POSS leads to the formation of POSS-rich clusters well dispersed in the TPU matrix. SAXS and WAXS results show that the POSS domains are amorphous and that POSS does not modify the crystalline structure of TPU. Therefore, this work indicates that synthesizing TPU in the presence of trisilanol isooctyl POSS can increase the melt thermal stability of the polymer, facilitating its processing.


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1443
Author(s):  
Tae-Kyung Kim ◽  
Min Hyeock Lee ◽  
Hae In Yong ◽  
Samooel Jung ◽  
Hyun-Dong Paik ◽  
...  

In this study, we investigated the effect of replacing myofibrillar protein (pork ham) with edible insect proteins (Tenebrio molitor L.) in meat emulsion systems and examined the interaction between the two types of proteins. We also evaluated the rheological properties and thermal stability of these meat emulsions. The replacement ratios of myofibrillar protein and edible insect protein were as follows: 100:0 (EI0), 80:20 (EI20), 60:40 (EI40), 40:60 (EI60), 20:80 (EI80), and 0:100 (EI100). The pH, redness, and yellowness of the emulsion systems, after replacing myofibrillar protein with T. molitor protein, significantly increased with T. molitor protein concentrations. In contrast, the lightness, hardness, cohesiveness, gumminess, chewiness, apparent viscosity, and differential scanning calorimetry (DSC) of the emulsion systems decreased significantly with increasing T. molitor protein concentrations. The backscattering values of EI0, EI20, and EI40 decreased evenly in all spots of the dispersions as the storage time increased. Thus, up to 40% of pork myofibrillar protein could be replaced with T. molitor protein in meat emulsion systems. The results also suggest that the interaction between edible insect protein and myofibrillar protein degrades the rheological properties and thermal stability of the meat emulsion systems.


2011 ◽  
Vol 79 ◽  
pp. 282-287 ◽  
Author(s):  
Yi Chen ◽  
Guang Sheng Zeng ◽  
Ping Jiang ◽  
Wei Lu ◽  
Wei Long Huang

EVA was added into PC/PLA blends as a modifier for improving the impact strength of blends, and meanwhile the thermal properties and rheological properties of blends should also be influenced. PC/PLA/EVA blends were prepared by melt blending and the catalyst DBTO was added into the blends in blending process to catalyze the transesterification of PC and EVA for improving the compatibility of blends. The effects of blend composition and transesterification on the thermal and rheological properties of blends were investigated. The results showed that the addition of EVA could improve the crystallinity of PLA in PC/PLA/EVA blends but had little influence on the thermal stability of blends,and the transesterification was beneficial to both the crystallization of PLA and thermal stability of blends. The addition of EVA and the transesterification of PC and EVA increased the apparent viscosity of blends, while the apparent viscosity of blends decreased drastically and the pseudo-plasticity characteristic of blend melts was weakened obviously with increasing PLA content and rising temperature.


2018 ◽  
Vol 75 (12) ◽  
pp. 5551-5566 ◽  
Author(s):  
Fouzia Zoukrami ◽  
Nacerddine Haddaoui ◽  
Michel Sclavons ◽  
Jacques Devaux ◽  
Celine Vanzeveren

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3742
Author(s):  
Xiaozhou Xu ◽  
Yi Liu ◽  
Bangwei Lan ◽  
Song Mo ◽  
Lei Zhai ◽  
...  

A series of 4-phenylethnylphthalic anhydride (PEPA)-terminated oligoimides were prepared by co-oligomerizing isomeric dianhydrides, i.e., 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA), 2,3,3′,4′-benzophenonetetracarboxylic dianhydride (a-BTDA) or 2,3,3′,4′-diphenylethertetracarboxylic dianhydride (a-ODPA), with diamines mixture of bis(4-aminophenoxy)dimethyl silane (APDS) and 2,2′-bis(trifluoromethyl) benzidine (TFDB). The effects of siloxane content and dianhydride structure on the rheological properties of these oligoimides and thermal stability of the corresponding cured polyimide resins were investigated. The results indicated that the introduction of the siloxane structure improved the melt processability of the oligoimides, while the thermal stability of the cured polyimide resins reduced. The oligoimide derived from a-ODPA revealed better melt processability and melt stability due to the existence of a flexible dianhydride structure. The oligoimide PIS-O10 derived from a-ODPA gave the lowest minimum melt viscosity of 0.09 Pa·s at 333 °C and showed the excellent melt stability at 260 °C for 2 h with the melt viscosity in the range of 0.69–1.63 Pa·s. It is also noted that the thermal stability of these resins can be further enhanced by postcuring at 400–450 °C, which is attributed to the almost complete chemical crosslinking of the phenyethynyl combined with oxidative crosslinking of siloxane. The PIS-T10 and PIS-O10 resins that were based on a-BTDA and a-ODPA, respectively, even showed a glass transition temperature over 550 °C after postcuring at 450 °C for 1 h.


2006 ◽  
Vol 77 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Rungnaphar Pongsawatmanit ◽  
Theeranan Temsiripong ◽  
Shinya Ikeda ◽  
Katsuyoshi Nishinari

2015 ◽  
Vol 1105 ◽  
pp. 3-6
Author(s):  
A.A. Yussuf ◽  
M.A. Al-Saleh ◽  
S.T. Al-Enezi

The performances of PP/MMT nanocomposite (70μm thick films), in terms of thermal and rheological properties were investigated. A twin-screw extruder was used to compound PP, MMT, compatibilizer, and extruded nanocomposite films were collected for test. All results were compared and the influence of MMT contents on the final properties were observed and reported. The thermal properties of PP had improved by increasing MMT content from 0-3 phr. However at 4 phr thermal stability of the nanocomposite had slightly dropped. In terms of rhelogical properties, the addition of MMT to the PP blend increased the complex viscosity of the nanocomposites, particularly at low frequency regions.


2018 ◽  
Vol 762 ◽  
pp. 226-230 ◽  
Author(s):  
Janis Kajaks ◽  
Karlis Kalnins ◽  
Juris Matvejs

Article summarizes investigation results of rheological and thermal stability properties of industrially prepared wood plastic composites, based on virgin polypropylene and birch wood plywood production residues-plywood sanding dust (PSD). WPCs PP+40 wt. % PSD contain different modifiers, such as lubricant Struktol TWP (blend of an aliphatic carboxylic acid salts and mono and diamides), sterically hindered phenolic antioxidant 1010, thermal stabilizer 168 (hydrolytically stable phosphite), UV stabilizer 770-low molecular weight hindered amine light stabilizer (HALS) and pigments based on LDPE. According to our studies, we could conclude that rheological properties studied by capillary rheometer method, strongly depends on WPCs composition. MFI values fluctuate in limits from 0.212 up to 0.724 g/10min. that is changes 3.4 times. Thermal and antioxidant stabilizers promote increase of thermal stability of WPCs noted by TGA. Curves of fluidity indicates character of typical pseudo-plastic liquids for which viscosity not only depends on temperature and shear stress and deformation rate, but also decrease with increase of shear rate. That confirms fluidity index n values which are smaller than 1.


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