scholarly journals Extrusion and Injection Molding of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx): Influence of Processing Conditions on Mechanical Properties and Microstructure

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4012
Author(s):  
Chris Vanheusden ◽  
Pieter Samyn ◽  
Bart Goderis ◽  
Mouna Hamid ◽  
Naveen Reddy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mold Temperature ◽  
Melt Processing ◽  
Polymer Chains ◽  
Processing Temperature ◽  
Processing Conditions ◽  
Homogeneous Microstructure ◽  
Optimal Processing ◽  
Flexible Packaging ◽  
Factorial Design Of Experiments

Biobased and biodegradable polyhydroxyalkanoates (PHAs) have great potential as sustainable packaging materials. However, improvements in their processing and mechanical properties are necessary. In this work, the influence of melt processing conditions on the mechanical properties and microstructure of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is examined using a full factorial design of experiments (DoE) approach. We have found that strict control over processing temperature, mold temperature, screw speed, and cooling time leads to highly increased elongation at break values, mainly under influence of higher mold temperatures at 80 °C. Increased elongation of the moldings is attributed to relaxation and decreased orientation of the polymer chains together with a homogeneous microstructure at slower cooling rates. Based on the statistically substantiated models to determine the optimal processing conditions and their effects on microstructure variation and mechanical properties of PHBHHx samples, we conclude that optimizing the processing of this biopolymer can improve the applicability of the material and extend its scope in the realm of flexible packaging applications.

scholarly journals Structure-Properties Relations for Polyamide 6, Part 2: Influence of Processing Conditions during Injection Moulding on Deformation and Failure Kinetics

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 779 ◽  
Author(s):  
Emanuele Parodi ◽  
Gerrit Peters ◽  
Leon Govaert
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Mold Temperature ◽  
Polyamide 6 ◽  
Testing Temperature ◽  
Full Description ◽  
Time To Failure ◽  
Processing Conditions ◽  
Creep Tests ◽  
Deformation And Failure

The effect of processing conditions during injection on the structure formation and mechanical properties of injection molded polyamide 6 samples was investigated in detail. A large effect of the mold temperature on the crystallographic properties was observed. Also the the effect of pressure and shear flow was taken in to consideration and analysed. The yield and failure kinetics, including time-to-failure, were studied by performing tensile and creep tests at several test temperatures and relative humidities. As far as mechanical properties are concerned, a strong influence of temperature and relative humidity on the yield stress and time-to-failure was found. A semi-empirical model, able to describe yield and failure kinetics, was applied to the experimental results and related to the crystalline phase present in the sample. In agreement with findings in the literature it is observed that for high mold temperatures the sample morphology is more stable with respect to humidity and temperature than in case of low mold temperatures and this effects could be successfully captured by the model. The samples molded at low temperatures showed, during mechanical testing, a strong evolution of the crystallographic properties when exposed to high testing temperature and high relative humidity, i.e., an increase of crystallinity or a crystal phase transition. This makes a full description of the mechanical behavior rather complicated.

scholarly journals Potato Starch Hydrogels Produced by High Hydrostatic Pressure (HHP): A First Approach

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1673 ◽  
Author(s):  
Dominique Larrea-Wachtendorff ◽  
Gipsy Tabilo-Munizaga ◽  
Giovanna Ferrari
Keyword(s):  
Mechanical Properties ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Potato Starch ◽  
Water Concentration ◽  
Medium Size ◽  
Processing Temperature ◽  
Processing Conditions ◽  
Scanning Calorimetry ◽  
Absorption Bands

Starch-based hydrogels have received considerable interest due to their safe nature, biodegradability and biocompatibility. The aim of this study was to verify the possibility of producing natural hydrogels based on potato starch by high hydrostatic pressure (HHP), identifying suitable processing conditions allowing to obtain stable hydrogels, as well as to characterize structural and mechanical properties of these products. Sieved (small size granules and medium size granules) and unsieved potato starch samples were used to prepare aqueous suspensions of different concentrations (10–30% w/w) which were processed at 600 MPa for 15 min at different temperatures (25, 40 and 50 °C). Products obtained were characterized by different techniques (light and polarized microscopy, Fourier transform infrared spectroscopy (FTIR), rheology and differential scanning calorimetry (DSC)). Results obtained so far demonstrated that potato starch suspensions (20% starch–water concentration (w/w)) with granules mean size smaller than 25 µm treated at 600 MPa for 15 min and 50 °C showed a complete gelatinization and gel-like appearance. Potato HHP hydrogels were characterized by high viscosity, shear-thinning behavior and a highly structured profile (G’ >> G’’). Moreover, their FTIR spectra, similarly to FTIR profiles of thermal gels, presented three absorption bands in the characteristic starch-gel region (950–1200 cm−1), whose intensity increased with decreasing the particle size and increasing the processing temperature. In conclusion, potato starch hydrogels produced by HHP in well-defined processing conditions exhibited excellent mechanical properties, which can be tailored according to the requirements of the different applications envisaged.

Blended Elemental P/M Synthesis of Titanium Alloys and Titanium Alloy-Based Particulate Composites

2007 ◽  
Vol 534-536 ◽  
pp. 777-780
Author(s):  
Masuo Hagiwara ◽  
Satoshi Emura
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Titanium Alloys ◽  
Alloy Powder ◽  
High Cycle Fatigue ◽  
Particulate Composites ◽  
Processing Conditions ◽  
Cycle Fatigue ◽  
Blended Elemental ◽  
Optimal Processing

Titanium alloys and Titanium alloy-based particulate composites were synthesized using the blended elemental P/M route. First, processing conditions such as the fabrication of master alloy powder were investigated. Ti-6Al-4V, Ti-5Al-2.5Fe, Ti-6Al-2Sn-4Zr-2Mo, IMI685, IMI829, Timetal 1100 and Timetal 62S, and Ti-6Al-2Sn-4Zr-2Mo/10%TiB and Timetal 62S/10%TiB were then synthesized using the optimal processing conditions obtained. The microstructures and mechanical properties such as tensile strength and high cycle fatigue strength were evaluated.

Effect of Ground Tyre Rubber Devulcanisates on the Properties of a Passenger Car Tyre Tread Formulation

2013 ◽  
Vol 844 ◽  
pp. 425-428
Author(s):  
A.I.H. Habibah Dayang ◽  
Sitisaiyidah Saiwari ◽  
Wilma Dierkes ◽  
Jacques W.M. Noordermeer
Keyword(s):  
Mechanical Properties ◽  
Environmental Issues ◽  
Polymer Chains ◽  
Raw Material ◽  
Processing Conditions ◽  
Passenger Car ◽  
Cure Characteristics ◽  
Cross Links ◽  
Ground Tyre Rubber ◽  
Waste Tyre

Extensive research on recycling processes, in particular for waste tyre material, is necessary due to increasing raw material costs, diminishing resources and growing awareness of environmental issues. One of the preferred methods is devulcanisation, in which only sulphur cross-links are broken, while the polymer chains remain intact. In this study, optimised processing conditions for the devulcanisation of whole passenger car tyres using diphenyldisulphide (DPDS) as a devulcanisation aid were applied. The devulcanised ground tyre rubber (D-GTR) obtained from the process was blended on top of the original tyre tread formulation at different concentrations. The cure characteristics and mechanical properties of the re-vulcanised blends are evaluated in comparison to the original compound. The results so far indicate that the addition of D-GTR influences the properties of the blend, but to a lesser extent than the commercially used powder or reclaim types do, for which loadings less than 5% can be applied. The main reason for the influence of D-GTR on the rubber properties is inhomogeneities in the D-GTR/virgin rubber blend.

scholarly journals The Effect of SEBS/Halloysite Masterbatch Obtained in Different Extrusion Conditions on the Properties of Hybrid Polypropylene/Glass Fiber Composites for Auto Parts

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3560
Author(s):  
Zina Vuluga ◽  
Catalina-Gabriela Sanporean ◽  
Denis Mihaela Panaitescu ◽  
George Mihail Teodorescu ◽  
Mihai Cosmin Corobea ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Halloysite Nanotubes ◽  
Melt Processing ◽  
Processing Conditions ◽  
Twin Screw Extruders ◽  
Glass Fiber Composites ◽  
Twin Screw ◽  
Linear Poly ◽  
Lower Temperature

Masterbatches from a linear poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) and halloysite nanotubes (HNT-QM) were obtained in different conditions of temperature and shear using two co-rotating twin-screw extruders. The influence of screw configuration and melt processing conditions on the morpho-structural, thermal and mechanical properties of masterbatches at macro and nanoscale was studied. A good dispersion of halloysite nanotubes and better thermal stability and tensile and nanomechanical properties were obtained at a lower temperature profile and higher screw speed. The effect of masterbatches, the best and worst alternatives, on the properties of a polypropylene (PP)–glass fiber (GF) composite was also evaluated. Double hardness, tensile strength and modulus and four times higher impact strength were obtained for PP/GF composites containing masterbatches compared to pristine PP. However, the masterbatch with the best properties led further to enhanced mechanical properties of the PP/GF composite. A clear difference between the effects of the two masterbatches was obtained by nanoindentation and nanoscratch tests. These analyses proved to be useful for the design of polymer composites for automotive parts, such as bumpers or door panels. This study demonstrated that setting-up the correct processing conditions is very important to obtain the desired properties for automotive applications.

Effect of melt processing conditions on mechanical properties of polyvinylchloride/organoclay nanocomposites

2004 ◽  
Vol 33 (7) ◽  
pp. 287-294 ◽  
Author(s):  
L. Kovarova ◽  
A. Kalendova ◽  
J. Simonik ◽  
J. Malac ◽  
Z. Weiss ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Melt Processing ◽  
Processing Conditions

Morphology and Mechanical Properties of Polyethylene Terephthalate/Ethylene Propylene Diene Monomer (PET/EPDM) in the Presence of Nanoclay

2020 ◽  
Vol 57 (3) ◽  
pp. 249-259
Author(s):  
Baifen Liu ◽  
Mohammad Mirjalili ◽  
Peiman Valipour ◽  
Sajad Porzal ◽  
shirin Nourbakhsh
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Thermal Destruction ◽  
Processing Temperature ◽  
Tem Analysis ◽  
Maximum Stiffness ◽  
Cloisite 30B ◽  
Nano Clay ◽  
The Matrix ◽  
Sample Maximum

This research deals with the mechanical properties, microstructure, and interrelations of triple nanocomposite based on PET/EPDM/Nanoclay. These properties were examined in different percentages of PET/EPDM blend with compatibilizer (Styrene-Ethylene/Butylene-Styrene)-G-(Maleic anhydrate) (SEBS-g-MAH). Results showed that the addition of 15% SEBS-g-MAH improved the toughness and impact strength of this nanocomposite. SEM micrographs indicated the most stable fuzzy microstructure in a 50/50 mixture of scattered phases of EPDM/SEBS-g-MAH. The effects of percentages of 1, 3, 5, 7 nanoclay Cloisite 30B (C30B) on the improvement of the properties were evaluated. With the addition of nano clay, the toughness and impact strength was reduced. Thermal destruction of nanoclay in processing temperature led to the decreasing dispersion of clay plates in the matrix and a reduction in the distances of nano clay plates in the composite compared to pure nano clay. XRD and TEM analysis was used to demonstrate the results. By adding 1% of nanoclay to the optimal sample, maximum stiffness, and Impact strength, among other nanocomposites, was achieved.

Elastomer nanocomposites based on NBR/BR/nanoclay: morphology and mechanical properties

2013 ◽  
Vol 33 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Shohreh Tolooei ◽  
Ghasem Naderi ◽  
Shirin Shokoohi ◽  
Sedigheh Soltani
Keyword(s):  
Mechanical Properties ◽  
Polymer Chains ◽  
Butadiene Rubber ◽  
Cure Characteristics ◽  
Fluid Uptake ◽  
Roll Mill ◽  
Dispersion State ◽  
Cure Time ◽  
Diffraction Patterns ◽  
Nanoclay Content

Abstract Ternary elastomer nanocomposites based on acrylonitrile butadiene rubber (NBR), polybutadiene rubber (BR) and two types of nanoclay (Cloisite 15A and Cloisite 30B) were prepared using a laboratory scale two-roll mill. The effects of nanoclay composition on the cure characteristics, mechanical properties and morphology of NBR/BR (50/50) nanocomposite samples containing 3, 5, 7 and 10 wt% nanoclay were investigated. According to the cure characteristics both types of nanoclay caused a reduction in the scorch time and optimum cure time of the nanocomposite compound. X-ray diffraction patterns of all samples suggested the intercalation of polymer chains into the silicate layers. This was confirmed by transmission electron microscopy (TEM) micrographs. Dynamic mechanical thermal analysis (DMTA) was utilized to study the dispersion state of nanoclay within the elastomer blend matrix. The results showed the development of mechanical properties with the establishment of interactions between nanoclay and polymer chains. Antiknock and brake fluid uptake were also reduced with increasing the nanoclay content.

scholarly journals Melt- vs. Non-Melt Blending of Complexly Processable Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 404
Author(s):  
Nur Sharmila Sharip ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Yoshito Andou ◽  
Yuki Shirosaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Yield Strength ◽  
Young’S Modulus ◽  
High Molecular Weight ◽  
Melt Processing ◽  
Cellulose Nanofiber ◽  
Melt Blending ◽  
Ultra High Molecular Weight

The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.

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