scholarly journals Green TPUs from Prepolymer Mixtures Designed by Controlling the Chemical Structure of Flexible Segments

2021 ◽  
Vol 22 (14) ◽  
pp. 7438
Author(s):  
Paulina Kasprzyk ◽  
Ewa Głowińska ◽  
Paulina Parcheta-Szwindowska ◽  
Kamila Rohde ◽  
Janusz Datta
Keyword(s):  
Chemical Structure ◽  
Melt Flow Index ◽  
Molar Ratio ◽  
Flow Index ◽  
Step Method ◽  
Elongation At Break ◽  
Molecular Weights ◽  
Trimethylene Glycol ◽  
Hard Segments ◽  
A Chain

This study concerns green thermoplastic polyurethanes (TPU) obtained by controlling the chemical structure of flexible segments. Two types of bio-based polyether polyols—poly(trimethylene glycol)s—with average molecular weights ca. 1000 and 2700 Da were used (PO3G1000 and PO3G2700, respectively). TPUs were prepared via a two-step method. Hard segments consisted of 4,4′-diphenylmethane diisocyanates and the bio-based 1,4-butanodiol (used as a chain extender and used to control the [NCO]/[OH] molar ratio). The impacts of the structure of flexible segments, the amount of each type of prepolymer, and the [NCO]/[OH] molar ratio on the chemical structure and selected properties of the TPUs were verified. By regulating the number of flexible segments of a given type, different selected properties of TPU materials were obtained. Thermal analysis confirmed the high thermal stability of the prepared materials and revealed that TPUs based on a higher amount of prepolymer synthesized from PO3G2700 have a tendency for cold crystallization. An increase in the amount of PO3G1000 at the flexible segments caused an increase in the tensile strength and decrease in the elongation at break. Melt flow index results demonstrated that the increase in the amount of prepolymer based on PO3G1000 resulted in TPUs favorable in terms of machining.

Cable and Wire Application: Adoption of Nanomagnesium Hydroxide Blended with LDPE/EVA for Mechanical and Physical Properties

2013 ◽  
Vol 701 ◽  
pp. 202-206
Author(s):  
Ahmad Aroziki Abdul Aziz ◽  
Sakinah Mohd Alauddin ◽  
Ruzitah Mohd Salleh ◽  
Mohammed Iqbal Shueb
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Melt Flow Index ◽  
Low Density Polyethylene ◽  
Flow Index ◽  
Low Density ◽  
Elongation At Break ◽  
Mechanical And Physical Properties ◽  
Poly Ethylene ◽  
Loading Amount

Effect of nanoMagnesium Hydroxide (MH) nloading amount to the mechanical and physical properties of Low Density Polyethylene (LDPE)/ Poly (ethylene-co vinyl acetate)(EVA) nanocomposite has been described and investigated in this paper. The tensile strength results show that increased amount of nanofiller will decrease and deteriorate the mechanical properties. The elongation at break decreased continuously with increasing loading of nanofiller. Generally, mechanical properties become poorer as loading amount increase. Melt Flow Index values for physical properties also provide same trend as mechanical properties results. Increase filler amount reduced MFI values whereby increased resistance to the flow.

Rheology of Thermoplastic Polyurethanes

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Rheological Behavior ◽  
Thermoplastic Polyurethane ◽  
Complete Characterization ◽  
Chain Extender ◽  
Reaction Sequence ◽  
Molecular Weights ◽  
Soft Segments ◽  
Hard Segments ◽  
A Chain ◽  
Long Chain

Thermoplastic polyurethane (TPU) has received considerable attention from both the scientific and industrial communities (Hepburn 1982; Oertel 1985; Saunders and Frish 1962). Applications for TPUs include automotive exterior body panels, medical implants such as the artificial heart, membranes, ski boots, and flexible tubing. Figure 10.1 gives a schematic that shows the architecture of TPU, consisting of hard and soft segments. Hard segments, which form a crystalline phase at service temperature, are composed of diisocyanate and short-chain diols as a chain extender, while soft segments, which control low-temperature properties, are composed of difunctional long-chain polydiols with molecular weights ranging from 500 to 5000. The soft segments form a flexible matrix between the hard domains. TPUs are synthesized by reacting difunctional long-chain diol with diisocyanate to form a prepolymer, which is then extended by a chain extender via one of two routes: (1) by a dihydric glycol chain extender or (2) by a diamine chain extender. The most commonly used diisocyanate is 4,4’-diphenylmethane diisocyanate (MDI), which reacts with a difunctional polyol forming soft segments, such as poly(tetramethylene adipate) (PTMA) or poly(oxytetramethylene) (POTM), to produce TPU, in which 1,4-butanediol (BDO) is used as a chain extender. There are two methods widely used to produce TPU: (1) one-shot reaction sequence and (2) two-stage reaction sequence. The reaction sequences for both methods are well documented in the literature (Hepburn 1982). It should be mentioned that MDI/BDO/PTMA produces ester-based TPU. One can also produce ether-based TPU when MDI reacts with POTM using BDO as a chain extender. TPUs are often referred to as “multiblock copolymers.” In order to have a better understanding of the rheological behavior of TPUs, one must first understand the relationships between the chemical structure and the morphology; thus, a complete characterization of the materials must be conducted. The rheological behavior of TPU depends, among many factors, on (1) the composition of the soft and hard segments, (2) the lengths of the soft and hard segments and the sequence length distribution, (3) anomalous linkages (branching, cross-linking), and (4) molecular weight.

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.

Influence of Glycols on the Glycolysis Process and the Structure and Properties of Polyurethane Elastomers

2011 ◽  
Vol 43 (6) ◽  
pp. 529-541 ◽  
Author(s):  
J. Datta ◽  
J. T. Haponiuk
Keyword(s):  
Chain Elongation ◽  
Step Method ◽  
Polyurethane Elastomers ◽  
Elongation At Break ◽  
Tensile Tester ◽  
Molecular Masses ◽  
One Step ◽  
The Mean ◽  
A Chain ◽  
Glycolysis Process

In this work, the influence of glycols on the glycolysis process and the properties of obtained polyurethanes were investigated. The glycolysates were produced via glycolysis of waste polyurethane foam in the reaction with one of the following glycols: 1,3-propanediol, 1,5-pentanediol, and 1,6-hexanediol.The reactions were carried out for different mass ratios of polyurethane wastes to glycolysis agent, i.e. 6:1, 8:1, and 10:1. Polyurethanes were synthesized from the obtained intermediates by a one-step method of mixing polymeric di-isocyanate and the glycolysis products with molecular masses ranging from 700 to 1000, while a polyol (Poles 55/20) was used as a chain elongation agent. The influence of glycolysates on tensile strength and elongation at break of polyurethanes was investigated using a Zwick universal tensile tester. Thermal decomposition of the obtained glycolysates and polyurethanes was investigated by thermogravimetry coupled with Fourier transform infrared spectroscopy. It has been found that of all used glycols, 1,6-hexanediol gives the best improvement in the thermal stability of polyurethanes during the glycolysis process. The mean hardness of polyurethanes decreases but rebound resilience increases with chain length of the glycol used for obtaining glycolysates.

Tensile Properties and Melt Flow Index of Polypropylene/Ethylene Propylene Diene Monomer Nanocomposites

2015 ◽  
Vol 1107 ◽  
pp. 125-130 ◽  
Author(s):  
Muhammad Safwan Hamzah ◽  
M. Mariatti ◽  
M. Kamarol
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Melt Flow Index ◽  
Filler Loading ◽  
Flow Index ◽  
Ethylene Propylene Diene Monomer ◽  
Melt Flow ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Internal Mixer

In this article, we report three nanofillers filled polymer composite systems. Nanofillers composed of alumina, titania and organoclay were embedded separately in 50% polypropylene (PP) and 50% ethylene propylene diene monomer (EPDM) blends. The nanocomposites were prepared using an internal mixer and were molded using a compression mold to form test samples. Effect of filler loading (2, 4, 6, and 8 vol.%) on the tensile properties and melt flow index (MFI) were determined. The mechanical properties of alumina are the highest compared to titania and organoclay. Alumina and organoclay shows an ascending trend in tensile strength with the increase of nanofiller loading. In contrast, the increment of titania filler loading reduces the tensile strength of the nanocomposites. The Young's modulus of the nanocomposites increases with the addition of filler loading. Elongation at break of the nanocomposites shows a descending trend with the addition of filler loading. The addition of 8 vol. % titania and organoclay slightly changes the MFI of the PP/EPDM nanocomposites whereas the addition of 8 vol. % alumina drastically decreased the MFI values. Further addition of nanofillers up to 8 vol. % decreases the MFI values of the PP/EPDM nanocomposites.

Mechanical Properties of Superconcentrates Based on Ethylene-Vinyl Acetate Copolymer and Microcrystalline Cellulose

2020 ◽  
Vol 992 ◽  
pp. 306-310
Author(s):  
P.G. Shelenkov ◽  
P.V. Pantyukhov ◽  
A.A. Popov
Keyword(s):  
Mechanical Properties ◽  
Vinyl Acetate ◽  
Microcrystalline Cellulose ◽  
Melt Flow Index ◽  
Ethylene Vinyl Acetate ◽  
Flow Index ◽  
Rheological Characteristics ◽  
Elongation At Break ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

In the study, highly filled superconcentrates based on various grades of ethylene-vinylacetate copolymer (EVA) and microcrystalline cellulose (MCC) were studied. It is assumed that adding superconcentrates to various polyolefins will make them biodegradable in the environment. The influence of EVA rheological characteristics and the content of vinyl acetate (VA) groups on the properties of the superconcentrates were studied. It was shown that increasing the concentration of VA groups in EVA leads to an increase in the elongation at break of the composites; increase in EVA melt flow index (MFI) greatly reduces the basic mechanical properties of the composite.

Properties of Films Prepared as Packaging Plastics from Blends of Synthetic Polymer and Biopolymer

2019 ◽  
Vol 394 ◽  
pp. 85-89
Author(s):  
Kęstutis Beleška ◽  
Virgilijus Valeika ◽  
Virginija Jankauskaite ◽  
Violeta Valeikiene
Keyword(s):  
Tensile Strength ◽  
Tensile Test ◽  
Soybean Oil ◽  
Melt Flow Index ◽  
Synthetic Polymer ◽  
Flow Index ◽  
Melt Flow ◽  
Elongation At Break ◽  
Biopolymer Blends ◽  
Main Factor

Natural biopolymers were studied for their possible role as biodegradable fillers forlow-density polyethylene (LDPE) films. LDPE/biopolymer blends and films were prepared andcharacterized by the melt flow index (MFI) and tensile test. The addition of biopolymer to LDPEreduced the MFI values, the tensile strength and modulus, whereas the elongation at break increased.Interfacial interaction was better for LDPE/biopolymer blends containing soybean oil. Blendsprepared with oil showed the same behaviour as LDPE/biopolymer blends, indicating thatbiopolymer was the main factor that influenced the properties of blend.

scholarly journals PREPARATON OF MASTERBATCH CONTAINING ANTI-OXIDATION ADDITIVE: EFFECT OF CARRIER RESIN RATIO AND ADDITIVES CONTENT

2018 ◽  
Vol 56 (2A) ◽  
pp. 56-62
Author(s):  
Nguyen Van Khoi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Sem Images ◽  
Elongation At Break ◽  
Limit Value ◽  
Upper Limit ◽  
Anti Oxidant

In this article, we investigated effect of carrier resin ratio and anti-oxidation additives content on properties of anti-oxidant additives Masterbatchs (MBs). The characteristics were measured by: melt flow index (MFI), morphology (SEM), tensile strength and elongation at break. The results indicated that: increasing LLDPE content in carrier resin led to decreasing mechanical properties, MFI weren’t uniform in MBs. With 80/20 of LDPE/LLDPE ratio, the tensile strength and elongation at break values were highest (21.0 MPa, 680.5 %). In addition, when increased anti-oxidant additives content, mechanical properties increased to upper limit value, then decreased. With 25 wt.% of anti-oxidant additives, the tensile strength and elongation at break values were highest (21.0 MPa, 654.7 %), MFI were uniform in MBs (12 g/10 m). SEM images were evidence of greatly distribution in sample containing 25 wt.% additives. Consequently, the 90/10 of LDPE/LLDPE ratio, 25 wt.% anti-oxidant additives were selected to prepare MBs. 

Mechanical, Thermal and Rheological Properties of Reprocessable Poly(Butylene Succinate)

2018 ◽  
Vol 928 ◽  
pp. 3-8
Author(s):  
Natkrita Prasoetsopha ◽  
Jessada Didsabong ◽  
Kunlaya Sonthonglang ◽  
Patcharaporn Somdee ◽  
Witawat Singsang ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Melt Flow Index ◽  
Degree Of Crystallinity ◽  
Flow Index ◽  
Butylene Succinate ◽  
Cycle Number ◽  
Elongation At Break ◽  
Biodegradable Poly ◽  
Plastic Industry

In the plastic industry, recycling waste from production is normal practice for reducing waste and cost. When they were reproduced, their mechanical properties are changed. These changes may affect the quality of the end product. Hence, this work studied the mechanical, thermal and rheological properties of recycled biodegradable poly (butylene succinate) (PBS) with reproduction of 10 cycles. The results showed that tensile strength was slightly increased with increasing reproduction cycle until 6thcycles and reduced in the further cycles, respectively. The elongation at break was abruptly decreased with an increase of the cycle number. Moreover, the hardness was quite constant in the lower cycle number but it was slightly decreased in the higher one. Melt flow index (MFI) measurements indicated a significant change in the material after 2rdrecycles. The results on thermal properties measurement showed that degree of crystallinity decreased in the 6thcycles.

scholarly journals PHYSICOMECHANICAL PROPERTIES OF NANOCOMPOSITES BASED ON COPOLYMERS OF ETHYLENE WITH α-OLEFINS AND CLINOPTILOLITE

2020 ◽  
pp. 22-27
Author(s):  
N.T. Kakhramanov ◽  
◽  
I.V. Bayramova ◽  
V.S. Osipchik ◽  
A.D. Ismayilzade ◽  
...  
Keyword(s):  
Particle Size ◽  
Tensile Stress ◽  
Heat Resistance ◽  
Flexural Modulus ◽  
Melt Flow Index ◽  
Ultimate Tensile Stress ◽  
Physicomechanical Properties ◽  
Flow Index ◽  
Ethylene Copolymers ◽  
Elongation At Break

The results of studying the effect of clinoptilolite concentration on the properties of nanocomposites based on of ethylene with butylene and of ethylene with hexene copolymer are presented. The effect of clinoptilolite particle size on ultimate tensile stress, elongation at break, flexural modulus, heat resistance, and melt flow index of composites was studied. It is shown that nanocomposites based on ethylene copolymers are characterized by higher values of physicomechanical properties. The additional use of ingredients such as alizarin and calcium stearate contributes to a significant improvement in the complex of properties of nanocomposites based on ethylene copolymers and clinoptilolite

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