Preparation of high molecular weight and elastic copolyester by reactive extrusion with diisocyanate compound for laser printing process

2012 ◽  
Vol 32 (3) ◽  
Author(s):  
Hyung-Jin Roh ◽  
Doe Kim ◽  
Dong-Ho Lee ◽  
Keun-Byoung Yoon
Keyword(s):  
Rheological Properties ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Melt Flow Index ◽  
Reactive Extrusion ◽  
Flow Index ◽  
Printing Process ◽  
Laser Printing ◽  
Printing Processes ◽  
Trimethylol Propane

Abstract A branched copolyester was synthesized using dimethyl terephthalate (DMT), 2,2-bis[4-(2-hydroxypropoxy)phenyl]propane, ethylene glycol (EG) and 2-(hydroxymethyl)-2- ethylpropane-1,3-diol (trimethylol propane, TMP). The branched copolyester and p-phenylene diisocyanate (PPDI) were melt extruded to enhance the melt viscosity and elasticity for use as a toner binder in the laser printing process. The effects of PPDI content on melt, thermal and rheological properties of the chain-extended copolyester were investigated. The melt flow index (MI) decreased with increasing amount of PPDI, due to a reaction between the hydroxyl chain end and isocyanate group. The storage modulus, loss modulus and complex viscosity of the chain extended copolyester were higher and the modified Cole-Cole plots revealed the chain extended copolyester to have higher elasticity than that of the branched copolyester. The chain extended copolyester exhibited suitable melt and rheological properties for applications as a toner binder in the laser printing processes.

Thermal and rheological properties of self-fabricated polyethylene glycol-plasticized poly(lactic acid) filaments for fused deposition modeling

2020 ◽  
pp. 147776062091859
Author(s):  
Nor Fazreeniza Nor Ashikin ◽  
Raa Khimi Shuib ◽  
Ku Marsilla Ku Ishak ◽  
Zuratul Ain Abdul Hamid ◽  
Muhammad Khalil Abdullah ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Rheological Properties ◽  
Fused Deposition Modeling ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Poly Lactic Acid ◽  
Flow Index ◽  
Fused Deposition ◽  
Molecular Arrangement ◽  
Deposition Modeling

In this work, thermal and rheological properties of self-fabricated polylactic acid (PLA) filaments without and with 10-wt% polyethylene glycol (PLA/0PEG and PLA/10PEG, respectively) were investigated, and the properties were compared with a commercial PLA filament used for fused deposition modeling (FDM). The result showed that the melt flow index for self-fabricated filaments was comparable with commercial filaments at approximately 10 g/10 min at 190°C, suggesting suitability to be used as filament for FDM with well-wetted layers. Variation in thermal properties was found in PLA/10PEG with 20°C higher cold crystallization temperature ( T cc) after FDM in which disruption of the molecular arrangement reduced the ability for chain alignment and folding. The result also revealed that addition of PEG decreased the storage modulus ( G′), loss modulus ( G″), and complex viscosity ( η*), resulting in slow crystallization behavior, and however, the properties did not induce degradation of the filaments and printing products.

Electrical conductivity and rheological properties of carbon black based conductive polymer composites prior to and after annealing

2021 ◽  
pp. 096739112110012
Author(s):  
Qingsen Gao ◽  
Jingguang Liu ◽  
Xianhu Liu
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Rheological Properties ◽  
Network Formation ◽  
Loss Modulus ◽  
Conductive Polymer ◽  
Complex Viscosity ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.

Mixtures of Recycled Milk Pouches with a Virgin LDPE-LLDPE Blend

2005 ◽  
Vol 21 (3) ◽  
pp. 219-230 ◽  
Author(s):  
Arup Choudhury ◽  
Mandira Mukherjee ◽  
Basudam Adhikari
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rheological Properties ◽  
Melt Flow Index ◽  
Flow Index ◽  
Thermal And Mechanical Properties ◽  
Melt Flow ◽  
Recycled Materials ◽  
Elongation At Break

The present investigation deals with the viability of the use of recycled milk pouch material, which is a 50:50 mixture of LDPE and LLDPE, and the scope for improvement of its properties by combining it with virgin LDPE-LLDPE (50/50). Melt flow index (MFI), rheological properties, thermal and mechanical properties of the pure materials and their formulated blends containing recycled milk pouches were studied. The properties of the recycled materials were not as satisfactory as those of the corresponding virgin materials. But a significant improvement in viscosity, crystallinity, tensile strength and elongation at break of the recycled LDPE-LLDPE material was achieved by blending it with the corresponding virgin LDPE-LLDPE blend.

scholarly journals Reactive Extrusion of Maleic-Anhydride-Grafted Polypropylene by Torque Rheometer and Its Application as Compatibilizer

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 495
Author(s):  
Asra Tariq ◽  
Nasir M. Ahmad ◽  
Muhammad Asad Abbas ◽  
M Fayzan Shakir ◽  
Zubair Khaliq ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Maleic Anhydride ◽  
Benzoyl Peroxide ◽  
Melt Flow Index ◽  
Reactive Extrusion ◽  
Side Chain ◽  
Flow Index ◽  
Viscosity Change ◽  
Chain Reactions ◽  
Molecular Weight Product

This study is based upon the functionalization of polypropylene (PP) by radical polymerization to optimize its properties by influencing its molecular weight. Grafting of PP was done at different concentrations of maleic anhydride (MAH) and benzoyl peroxide (BPO). The effect on viscosity during and after the reaction was studied by torque rheometer and melt flow index. Results showed that a higher concentration of BPO led to excessive side-chain reactions. At a high percentage of grafting, lower molecular weight product was produced, which was analyzed by viscosity change during and after the reaction. Percentage crystallinity increased by grafting due to the shorter chains, which consequently led to an improvement in the chain’s packing. Prepared Maleic anhydride grafted polypropylene (MAH-g-PP) enhanced interactions in PP-PET blends caused a partially homogeneous blend with less voids.

scholarly journals Effects of Heating Temperature and Load Weight on Rheological Properties of Waste Plastic Cup

2021 ◽  
Vol 17 (1) ◽  
pp. 39-49
Author(s):  
Halimatuddahliana Nasution ◽  
Winny Winny
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Rheological Properties ◽  
Heating Temperature ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Waste Plastic ◽  
Load Weight ◽  
Increasing Load

Analysis of heating temperature and load weight to the rheological properties of waste plastic cups is very important to gain fundamental understanding of the structure, characteristics, and processability of the material. The samples were tested using melt flow indexer. The heating temperature investigated were 180°C, 190°C, 200°C, 210°C, 220°C and 230°C, and the weight load were 1,875 g, 2,160 g, 2,835 g, 3,035 g and 3,450 g. The results obtained showed that the rheological properties of products such as melt flow index, shear stress and shear rate increased and the viscosity decreased with the increasing of heating temperature and load weight. For higher heating temperatures, the melt flow index, shear stress and shear rate of waste plastic cup increased significantly with the increasing load weight whereas the viscosity of waste plastic cup did not decrease significantly with the increasing load weight.

scholarly journals EFFECT OF POLYETHYLENE MOLECULAR MASS CHARACTERISTICS ON SLIP EFFECT

2016 ◽  
Vol 11 (5) ◽  
pp. 91-93
Author(s):  
A. A. Yurkin ◽  
I. D. Simonov-Emelyanov ◽  
P. V. Surikov ◽  
N. L. Shembel
Keyword(s):  
Molecular Weight ◽  
Molecular Mass ◽  
Rheological Properties ◽  
Melt Flow Index ◽  
Flow Index ◽  
Slip Effect ◽  
Melt Flow ◽  
Molecular Weight Characteristics ◽  
Different Temperatures ◽  
Different Molecular Weight

The rheological properties of polyethylene with different molecular weight characteristics were studied. Difference of molecular weight characteristics was found on the basis of melt flow index, and slip effect in the molten polyethylene flow was studied. The presence of slip effect is found in case of flowing polyethylene with a higher molecular weight in contrast to polyethylene with lower molecular weight at different temperatures. Changes of the slip effect parameters upon mixing polyethylenes with very much different molecular weight characteristics were studied.

scholarly journals New Evidences on the Process Sensitivity of Some Renewable Blends Based on Starch considering Their Melt Rheological Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Doina Dimonie ◽  
Marius Petrache ◽  
Celina Damian ◽  
Liliana Anton ◽  
Miruna Musat ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Corn Starch ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Melt Processing ◽  
Chemical Degradation ◽  
Flow Index ◽  
Cross Linking ◽  
Temperature Sensitive ◽  
Renewable Materials

The degradability and processability of new renewable materials based on starch and PVOH were studied using the melt flow index (MFI) method by measuring the melt rheological properties which depend not only on the extrusion conditions and material formulation but also on the macromolecule characteristics which can be modified by chemical degradation. These results were correlated with other material properties like color and cross-linking degree. The obtained results show that flowing in the melted state of the studied materials is accompanied by a second process of chains chemical degradation. It was observed that, at the same level of additivation, under identical extrusion conditions, the melted blends with corn starch as main component are highly mechanically sensitive and degrade mostly by chains scission and those with PVOH as major component are highly temperature sensitive and degrade mainly by cross-linking. The obtained results show also that each PVOH-starch blend requires particular formulation and individual windows of melt processing conditions. These results are a good proof that the MFI method is a good path to study the degradability and moldability of process sensitive polymeric materials like those based on starch and PVOH.

Evaluating the gas-laden ability of polymer melt under atmospheric conditions using a modified torque rheometer

2021 ◽  
pp. 0021955X2199735
Author(s):  
Xing-Yu Mei ◽  
Ying-Guo Zhou ◽  
Hong-Long Sun ◽  
Bin-Bin Dong ◽  
Chun-Tai Liu ◽  
...  
Keyword(s):  
Rheological Properties ◽  
High Density Polyethylene ◽  
Polymer Melts ◽  
Polymer Melt ◽  
Melt Flow Index ◽  
Flow Index ◽  
Atmospheric Conditions ◽  
Molding Machine ◽  
Rheological Measurement ◽  
Foaming Behavior

To investigate the effects of incorporating gas and the associated influencing factors on polymer melt, a method of evaluating the gas-laden ability using modified rheometric measurements was proposed. In this study, common and widely used thermoplastic materials—polypropylene (PP) and high-density polyethylene (HDPE), and their blends with different weight ratios—were selected, and the rheological properties of neat melt and gas-laden melts were tested using a modified torque rheometer. The foamed samples were also produced using a regular injection-molding machine, and the foamed morphology was examined by scanning electron microscope (SEM). The comparison of rheological curves of neat melt and gas-laden melt indicated that the incorporation of gas influenced the rheological properties of the gas-laden polymer melts as evidenced by a decrease of zero-rotational torque and an increase in the melt flow index. The results also suggested that the gas-laden ability of polymer melt could be evaluated quantitatively by the decay (due to desorption) of gas using the modified rheological measurement method. This study also demonstrated that the gas-laden ability can be used to predict the foaming behavior of polymer melts.

scholarly journals Influence of Reactive Chain Extension on the Properties of 3D Printed Poly(Lactic Acid) Constructs

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1381
Author(s):  
Maria-Eirini Grigora ◽  
Zoi Terzopoulou ◽  
Konstantinos Tsongas ◽  
Panagiotis Klonos ◽  
Nikolaos Kalafatakis ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Fused Deposition Modeling ◽  
Complex Viscosity ◽  
Melt Flow Index ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Flow Index ◽  
Mechanical And Thermal Properties ◽  
Fused Deposition ◽  
3D Printed

Fused deposition modeling (FDM) is currently the most popular 3D printing method, where thermoplastic polymers are predominantly used. Among them, the biobased poly(lactic acid) (PLA) governs the FDM filament market, with demand higher than supply, since not all grades of PLA are suitable for FDM filament production. In this work, the effect of a food grade chain extender (Joncryl ADR® 4400) on the physicochemical properties and printability of PLA marketed for injection molding was examined. All samples were characterized in terms of their mechanical and thermal properties. The microstructure of the filaments and 3D-printed fractured surfaces following tensile testing were examined with optical and scanning electron microscopy, respectively. Molecular weight and complex viscosity increased, while the melt flow index decreased after the incorporation of Joncryl, which resulted in filaments of improved quality and 3D-printed constructs with enhanced mechanical properties. Dielectric spectroscopy revealed that the bulk properties of PLA with respect to molecular mobility, both local and segmental, were, interestingly, not affected by the modifier. Indirectly, this may suggest that the major effects of the extender are on chain length, without inducing chain branching, at least not to a significant extent.

scholarly journals Rheological Properties of HDPE based Thermoplastic Polymeric Nanocomposite Reinforced with Multidimensional Carbon-based Nanofillers

2021 ◽  
Vol 12 (4) ◽  
pp. 5709-5715
Keyword(s):  
Rheological Properties ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Damping Factor ◽  
Equal Weight ◽  
Functional Elements ◽  
Weight Percentage ◽  
Potential Applications ◽  
Rheological Test

The present investigation focused on the evaluation of rheological properties HDPE reinforced with equal weight percentage (i.e., 0.1 wt. %) of Nano-diamond (0D), Carbon nanotubes (1D), and Graphite Nano-platelets (2D) multidimensional nanofillers. The results like storage modulus, loss modulus, Tan delta, and complex viscosity results expounded from the rheological test with a frequency sweep from 10-1 to 102 rad/s. The highest storage modulus was perceived by 0.1 CNT-based composites, i.e., 18408 Pa, which decreased to 19, 52, and 85 % for 0.1 GNP, 0.1 ND, and pure, respectively. A similar trend was observed for loss modulus and damping factor results. The shear-thinning behavior observed in viscosity results and the addition of ND nanofillers improve the viscosity to a large amount. The potential applications of the composites include polymer gears, landing mats, cams, and various functional elements.

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