scholarly journals Processing and Properties of MDF Fibre-Reinforced Biopolyesters with Chain Extender Additives

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Armin Thumm ◽  
Damien Even ◽  
Pierre-Yves Gini ◽  
Mathias Sorieul
Keyword(s):  
Molecular Weight ◽  
Fibre Composite ◽  
Fibre Length ◽  
Natural Fibre ◽  
Chain Extender ◽  
Strength Increase ◽  
Green Composite ◽  
Pull Out ◽  
A Chain ◽  
Tensile Strength Increase

Biopolyesters are a way to improve natural fibre composite sustainability. This study explores, for the first time, the potential of using medium density fibreboard (MDF) fibres to reinforce four biobased and biodegradable polyester matrices to create a fully “green composite.” Added at 30 wt %, MDF fibres did not improve the strength of the injection moulded NFCs and this deficiency was investigated by measuring fibre length, viscosity, and molecular weight of the matrices. Compared to other lignocellulosic fibres, the use of MDF fibres led to a molecular weight reduction of biopolyesters during processing. This effect was particularly striking for PLA. The addition of a chain extender enhanced the molecular weight of PLA and improved its processability. The tensile strength increase was correlated to a reduction of fibre pull-out, enabling the MDF fibre to fulfil its expected reinforcement role within the biopolyester composite.

Potential of Sisal Reinforced Biodegradable Polylactic Acid and Polyvinyl Alcohol Composites

2010 ◽  
Vol 425 ◽  
pp. 167-178 ◽  
Author(s):  
Iman M. Taha ◽  
Gerhard Ziegmann
Keyword(s):  
Polyvinyl Alcohol ◽  
Polylactic Acid ◽  
Failure Modes ◽  
Single Fibre ◽  
Natural Fibre ◽  
Natural Fibres ◽  
Green Composite ◽  
Surrounding Matrix ◽  
Pull Out ◽  
Fibre Composites

The application of natural fibres as polymer reinforcement is of extreme interest, especially in combination with biodegradable polymers. Such “green” composite represent a step forward to eco-design and environmentally friendly applications. The use of biodegradable polylactic acid (PLA) on the basis of renewable resources in addition to the biodegradable polyvinyl alcohol (PVA) on petrochemical basis is compared in this study with the application of polypropylene (PP) as a surrounding matrix for sisal fibres. According to the law of similarities, the chemically similar structure of natural fibres and PVA and PLA provides stronger fibre-matrix bonding characteristics compared to PP. This was experimentally validated applying single-fibre pull-out tests, where the effect of improved bonding is further investigated in terms of tensile and impact composite behaviour. SEM investigation was further applied to describe failure modes of natural fibre composites.

The Preparation of Poly(lactic acid) via Chain Linked Hydroxy-Terminated Lactic Acid Prepolymer

2011 ◽  
Vol 410 ◽  
pp. 337-340
Author(s):  
Suek Songprateepkul ◽  
Suriyan Rakmae ◽  
C. Deeprasertkul ◽  
Nitinat Suppakarn ◽  
Pranee Chumsamrong
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Average Molecular Weight ◽  
Glass Tube ◽  
Acid Value ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Poly Lactic Acid ◽  
Weight Average Molecular Weight ◽  
A Chain

In this work, hydroxyl-terminated lactic acid prepolymer was firstly prepared by adding diethylene glycol in the condensation of lactic acid. Molecular weight, acid value and structure of prepolymer were characterized. The results showed that the prepolymer was hydroxyl-terminated with weight average molecular weight (MW) of 10,000 g/mol. After that, the chain linking polymerization of the prepolymer was carried out in a glass tube at 160 °C for 1 h employing 1,6-hexamethylene diisocyanate (HMDI) as a chain extender. By varying the hydroxyl/isocyanate ratio, it was found that the OH/NCO ratio of 1:2 seemed to be the most suitable ratio which gave PLA with the maximum MW of 93,000 g/mol.

scholarly journals Polypropylene Glycol-Polyoxytetramethylene Glycol Multiblock Copolymers with High Molecular Weight: Synthesis, Characterization, and Silanization

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4317
Author(s):  
Wei Hu ◽  
Lei Wang ◽  
Quanyong Wang ◽  
Anbo Luan ◽  
Yuliang Mai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Average Molecular Weight ◽  
Chain Extender ◽  
Chain Extension ◽  
Polypropylene Glycol ◽  
Multiblock Copolymers ◽  
Oh Groups ◽  
Potential Applications ◽  
A Chain

The high crystallization at room temperature and high cost of polyoxytetramethylene glycol (PTMG) have become obstacles to its application. To overcome these problems, a segment of PTMG can be incorporated into a block copolymer. In this work, polypropylene (PPO) glycol-polyoxytetramethylene (PPO-PTMG) multiblock copolymers were designed and synthesized through a chain extension between hydroxyl (OH)-terminated PPO and PTMG oligomers. The chain extenders, feed ratios of the catalyst/chain extender/OH groups, reaction temperature, and time were optimized several times to obtain a PPO-PTMG with low crystallization and high molecular weight. Multiblock copolymers with low crystallization and high average molecular weight (Mn = 1.0–1.4 × 104 Dalton) were harvested using m-phthaloyl chloride as the chain extender. The OH-terminated PPO-PTMG multiblock copolymer with high Mn and a functionality near two was further siliconized by 3-isocyanatopropyltrimethoxysilane to synthesize a novel silyl-terminated polyether. This polyether has an appropriate vulcanizing property and potential applications in sealants/adhesive fields.

Processing and characterization of poly(lactic acid) blended with polycarbonate and chain extender

2014 ◽  
Vol 34 (7) ◽  
pp. 665-672 ◽  
Author(s):  
Yottha Srithep ◽  
Wuttipong Rungseesantivanon ◽  
Bongkot Hararak ◽  
Krisda Suchiva
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Gel Permeation Chromatography ◽  
Chain Extender ◽  
Chain Extension ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Commercial Applications ◽  
A Chain

Abstract Currently, use of poly(lactic acid) (PLA) is limited for commercial applications because it has a low heat resistance. In this research, an increase of over 40°C heat distortion temperature (HDT) of PLA alloy was obtained by blending PLA with polycarbonate (PC) and a chain extender (CE). Molecular weight, thermal, mechanical and morphological properties of PLA and PC blend with different CE contents were investigated. Gel permeation chromatography (GPC) results showed that some PLA-PC copolymers were produced and the compatibility of the PLA phase and in the PC phase was improved via the chain extension reaction. In addition, the reaction induced by CE also affected the crystallization behaviors of PLA, as observed from differential scanning calorimetry (DSC) results and the enthalpy of melting of PLA decreased with increasing CE content. The combined effects of the CE increasing molecular weight, improving compatibility and limiting the crystallization behavior of PLA/PC alloy greatly improved the HDT.

The Use of Controlled Dissolution Glass for the Consolidation of a High Porosity Chalk

2021 ◽  
Author(s):  
Max Olsen ◽  
Ragni Hatlebakk ◽  
Chris Holcroft ◽  
Roar Egil Flatebø ◽  
Asif Hoq ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Colloidal Silica ◽  
Strength Increase ◽  
High Porosity ◽  
Hydrocarbon Recovery ◽  
Filter Screen ◽  
The Matrix ◽  
Core Flood ◽  
Fractured Well ◽  
Tensile Strength Increase

Abstract This paper reports the development and testing, of a Phosphate controlled dissolution glass composition used to strengthen the matrix of chalk whilst retaining the permeability of the rock, facilitating improved hydrocarbon recovery in unstable wells. Multiple versions of the glass solutions and different types of colloidal silica were extensively tested in the laboratory to determine injectability and reactivity with calcium carbonate rocks. The goal of the testing was to determine the best performing solution for use in a field trial in the Norwegian North Sea. The laboratory testing included filtration and core flood tests to determine the injectability of the solutions and post treatment permeability, and Brazilian strength tests to determine the tensile strength of the treated chalk cores. The filterability was tested through filter screen sizes ranging from 5 to 0.6 µm. Core flood testing was performed on 10 cm long chalk cores with 1.5 mD permeability. The glass solutions showed the best results in the filtration and core flood testing, achieving significantly greater invasion depth than any of the colloidal silica samples. The phosphate glass treated chalk cores maintained 70 to 100% of the original permeability while delivering a 3 to 5 fold tensile strength increase. The lab tests demonstrated the potential of a glass based treatment to strengthen chalk formations without impeding permeability.Based on the promising results from the lab tests, it was decided to trial the selected glass solution in a mature vertical proppant fractured well. The test confirmed that the glass solution could be pumped into the well, but the test failed pre-maturely after two months of varied production, and the trial will not be covered in this paper.However, due to the high value in being able to stabilize chalk in the field, the Operator is evaluating a new trial in a horizontal well, and learnings from the first trial will be used to inform further lab tests in the next phase. The glass solution used in this trial is being further developed to be used in other formation types, such as sand and non-calcium containing reservoirs.

Novel Polyaspartic Ester Polyureas Based on Flexible Polyaspartic Ester

2011 ◽  
Vol 197-198 ◽  
pp. 1294-1298
Author(s):  
Ping Lu ◽  
Wei Bo Huang ◽  
Xue Qiang Ma ◽  
Xu Dong Liu
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Hydrogen Bonding ◽  
Molecular Weight Distribution ◽  
Michael Addition ◽  
Weight Distribution ◽  
Addition Reaction ◽  
Chain Extender ◽  
Michael Addition Reaction ◽  
Ft Ir

New polyaspartic ester (PAE) chain extender named PAE-f was prepared via two steps of Michael addition reactions:(1) Michael addition reaction between 4,4’-methylenebis(2-methyl cyclohexyl amine) (Laromin C260) and excessive dialkyl maleates（DEF）; (2) The Michael addition reaction of the residual dialkyl maleates of step (1) with polyester polyamine Jeffamine D230. The two-steps method proposed could reduce the reaction time in comparison with the current one step Michael addition reaction method, thus satisfying the industrialized production. New PAE based polyureas were synthesized by reacting the PAE-f chain extender with aliphatic polyisocyanates 4,4’-diisocyanato dicyclohexylmethane (H12MDI) / polyester polyamine Jeffamine D2000 prepolymer at room temperature. FT-IR and GPC were employed to characterize the new PAE prepared, and the morphology, molecular weight distribution and mechanical properties of the prepared PAE based polyureas were investigated by means of FT-IR and GPC. The FT-IR results indicated that the hydrogen bonding degree of amidogen groups in hard segments of the prepared polyureas were high, the length of hydrogen bonding were 0.305nm～0.306nm. The GPC experimental results show that the weight average molecular weight of the PAE-f based polyureas were 4.95×104～6.05×104,Mw/Mn were 1.65～1.97, the molecular weight distribution were relatively narrow. The mechanical properties demonstrated that the tensile strength were 14.7～22.5MPa, Elongation at break were 306～511%, Yang’s modulus were 67～127MPa, Shore A hardness were 64～83. The mechanical properties confirmed that the polyureas based on PAE-f were kinds of elastomeric materials with satisfied flexibility, strength, module and hardness.

Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites

2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Weihua Fan ◽  
Yue Zhao ◽  
Aijing Zhang ◽  
Yukun Liu ◽  
Yanxia Cao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Lactic Acid ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
A Chain

scholarly journals Synthesis of polylactic acid-diol (PLA-diol) from lactic acid and 1,4-butanediol

2016 ◽  
Vol 19 (4) ◽  
pp. 58-65
Author(s):  
Ha Thi Thai La
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
1H Nmr ◽  
Biodegradable Polymer ◽  
Average Molecular Weight ◽  
Chain Extension ◽  
Structure And Properties ◽  
Chain Reaction ◽  
A Chain

In this research, the PLA-diol were synthesized from lactic acid (LA) and 1.4 butanediols (BD) with a tin octoate Sn(Oct)2 catalyst at a temperature of 180 °C and the pressure 5 mmHg. The structure and properties of PLA-diol are analyzed by the following methods: GPC, 1H-NMR and DSC. As a result, with the change in the content of Sn (Oct)2 from 0.1 to 1.0%, the molecular weight Mn of PLA - diol increased gradually from 4.119,2 to 7.359,6 g / mol . In addition, the BD content increased from 2.0% to 5.0%, the average molecular weight of the product decreased gradually from 7.536,9 g / mol to 4.735 g / mol, respectively. This change will affect the ability to use PLA-diol in the next denaturation research to apply in the field of biodegradable polymer such as copolymer with polyurethane, copolymer with polyethylene glycol diacid, or chain extension with other polymer in a chain reaction,...

scholarly journals Better Wettability of Pandanus Utilis Alkaline Treated Fibres Tead to Higher Tensile Strengths of Composites.

2021 ◽  
Author(s):  
Laurent L'Entete ◽  
Hareenanden Ramasawmy
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Carbon Footprint ◽  
Fibre Length ◽  
Natural Fibre ◽  
Engineering Properties ◽  
Aggressive Treatment ◽  
High Carbon ◽  
Reinforcing Agent ◽  
Internal Angle

Abstract Composite materials made with synthetic fibres like E-glass, Kevlar or carbon have helped to provide a wide array of products to society with specific engineering properties. However, these materials have a high carbon footprint as well as being non-biodegradable. The use of natural fibre, as a substitution to these man-made fibres, has been studied and encouraging results are being obtained.In this study, the use of ‘Pandanus utilis’ fibre as a reinforcing agent in plastic was investigated with the aim of exploring specific properties such as the tensile strength of the fibre, its wettability and the effect of fibre length after treating the fibre with two different NaOH solutions. Results have shown that better reinforcement was obtained for the composites (11.10 ± 2.53MPa) with fibres subjected to a more aggressive treatment (2.5%NaOH for 2h) compared to the composite made with fibres having maximum tensile strength (168 ± 12MPa at 0.5% NaOH for 14h), due to a better hydrophilicity of the alkaline treated fibre (87.37° internal angle). Within the range of short chopped fibre length tested (6 to 15 mm), it was shown that there was a general decrease in the tensile strength of the composite.

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