Effects of ingredient proportions on the performance of α-Cellulose/PLA mixtures used for laser sintering

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5886-5898 ◽  
Author(s):  
Hui Zhang ◽  
Yanling Guo ◽  
David L. Bourell ◽  
Deyu Meng
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Cellulose Powder ◽  
Melt Temperature ◽  
Powder Feedstock ◽  
Biomass Materials ◽  
Sustainable Materials

A new powder feedstock composed of biocompatible and degradable biomass materials was introduced and evaluated for laser sintering in this research. The goal for the material is to facilitate high-value utilization of sustainable materials and expand the variety of feedstock that can be used for laser sintering. It was mechanically mixed with polylactic acid (PLA) powder and the filler of α-cellulose powder in the content of 5 wt%, 10 wt%, 15 wt%, and 20 wt%. The effects of the ingredient proportions were evaluated relative to laser sintering performance of α-cellulose/PLA mixtures. The results revealed that the increasing cellulose loading had almost no influence on the mixtures’ glass transition temperature, the melt temperature, and the crystallization temperature; thus, the mixtures would share the same processing parameters with neat PLA during the laser sintering fabrication. Although the cellulose loading reduced the materials’ melt fluidity and mechanical properties, it decreased the dimensional deformation of the laser-sintered parts and made the mixture more feasible as the feedstock of laser sintering compared to neat PLA.

Preliminary adhesive and composite properties of LARC™-CPI 2, a new semicrystalline polyimide

1993 ◽  
Vol 5 (3) ◽  
pp. 177-185 ◽  
Author(s):  
P M Hergenrothert ◽  
S J Havens
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
High Performance ◽  
Melt Temperature ◽  
High Molecular Weight Form ◽  
Aerospace Applications ◽  
Composite Properties ◽  
Molecular Weight Form

In continuation of an effort to develop processable high-performance structural resins for use in aerospace applications, a new polyimide. LARCTM-CPI 2, has been developed. This semicrystalline polyimide was prepared by the reaction of 4.4'-oxydiphthalic anhydride with 1,4-bis(4-aminophenoxy-4'-benzoyl)benzene. In high-molecular-weight form this material has a glass transition temperature of 223 C and a crystalline melt temperature of approximately 350 'C. Controlled-molecular-weight end-capped versions of LARCTM-CPI 2 were used to fabricate adhesive panels and composites that exhibited good mechanical properties at temperatures as high as 200 C.

scholarly journals Studies on the Modification of Commercial Bisphenol-A-Based Epoxy Resin Using Different Multifunctional Epoxy Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Tensile Fracture ◽  
Chemical Structures ◽  
Amino Phenol ◽  
Epoxy Systems

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.

scholarly journals Synthesis, Properties, and Biodegradability of Thermoplastic Elastomers Made from 2-Methyl-1,3-propanediol, Glutaric Acid and Lactide

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Lamya Zahir ◽  
Takumitsu Kida ◽  
Ryo Tanaka ◽  
Yuushou Nakayama ◽  
Takeshi Shiono ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glutaric Acid ◽  
Triblock Copolymers ◽  
Tensile Tests ◽  
Thermoplastic Elastomers ◽  
Proteinase K ◽  
Synthesis Properties

An innovative type of biodegradable thermoplastic elastomers with improved mechanical properties from very common and potentially renewable sources, poly(L-lactide)-b-poly(2-methyl-1,3-propylene glutarate)-b-poly(L-lactide) (PLA-b-PMPG-b-PLA)s, has been developed for the first time. PLA-b-PMPG-b-PLAs were synthesized by polycondensation of 2-methyl-1,3-propanediol and glutaric acid and successive ring-opening polymerization of L-lactide, where PMPG is an amorphous central block with low glass transition temperature and PLA is hard semicrystalline terminal blocks. The copolymers showed glass transition temperature at lower than −40 °C and melting temperature at 130–152 °C. The tensile tests of these copolymers were also performed to evaluate their mechanical properties. The degradation of the copolymers and PMPG by enzymes proteinase K and lipase PS were investigated. Microbial biodegradation in seawater was also performed at 27 °C. The triblock copolymers and PMPG homopolymer were found to show 9–15% biodegradation within 28 days, representing their relatively high biodegradability in seawater. The macromolecular structure of the triblock copolymers of PLA and PMPG can be controlled to tune their mechanical and biodegradation properties, demonstrating their potential use in various applications.

Glass transition temperature and thermal decomposition of cellulose powder

Cellulose ◽  
2007 ◽  
Vol 15 (3) ◽  
pp. 445-451 ◽  
Author(s):  
Ludwik Szcześniak ◽  
Adam Rachocki ◽  
Jadwiga Tritt-Goc
Keyword(s):  
Thermal Decomposition ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Cellulose Powder

Plasticization of poly(vinyl butyral) by water: Glass transition temperature and mechanical properties

2018 ◽  
Vol 136 (12) ◽  
pp. 47230 ◽  
Author(s):  
Marlène Desloir ◽  
Cyril Benoit ◽  
Amine Bendaoud ◽  
Pierre Alcouffe ◽  
Christian Carrot
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Water Glass ◽  
Vinyl Butyral

scholarly journals INFLUENCE OF ENVIRONMENTAL FACTORS ON PHYSICAL-MECHANICAL PROPERTIES OF POLYDIMETHYL ETHER OF NORBORENE -2;3-DICARBOXYLIC ACID

2017 ◽  
Vol 60 (5) ◽  
pp. 68 ◽  
Author(s):  
Galina S. Bozhenkova ◽  
Alexandra N. Tarakanovskaya ◽  
Oksana D. Tarnovskaya ◽  
Roman V. Ashirov
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Hydrochloric Acid ◽  
Environmental Factors ◽  
Dicarboxylic Acid ◽  
Uv Radiation ◽  
Accelerated Aging ◽  
The Impact

The article is devoted to the production of polymer by metathesis ring-opening polymerization under the influence of ruthenium initiator of type of Hoveyda-Grubbs II generation. The monomer used the mixture of dimethyl ether norbornene-2;3-dicarboxylic acid. The monomer was prepared by the Diels-Alder reaction of dicyclopentadiene and dimethyl maleate. The polymer was prepared in bulk of the monomer mixture. In this paper we have studied the physical and mechanical properties polydimethyl ether of norbornene-2;3-dicarboxylic acid; and assessed the impact of environmental factors on the change in properties of the polymer. As environmental factors; light; UV radiation; water; 0.1 M hydrochloric acid were applied; and accelerated aging conditions; which were held in a climate chamber. During performance we found that maintaining the polymer samples in the UV light chamber led to the slight increase in flexural modulus. In contrast; the polymer storage in water and in a hydrochloric acid solution for two months resulted in a slight decrease in the modulus of elasticity in bending index. These factors did not affect the change in the glass transition temperature of the polymer. Under the conditions of accelerated aging conducted for 1; 2 and 6 days after two cycles we observed the drop in modulus for bending of 8.5%; after 6 cycles of 13%. The glass transition temperature of polydimethyl ether of norbornene-2;3-dicarboxylic acid after 6 cycles decreased by only 3.4% in the climatic chamber. Studies have shown that the resulting polymer is resistant to water; hydrochloric acid; light and UV radiation; as well as it saves properties at a sufficient level for operation at conditions of accelerated aging. It should be noted that the tested polymer was prepared without additives; stabilizers and antioxidants. The proposed polymer can be used as a structural material for machine parts; including bulky.For citation:Bozhenkova G.S.; Tarakanovskaya A.N.; Tarnovskaya O.D.; Ashirov R.V. Influence of environmental factors on physical-mechanical properties of polydimethyl ether of norborene -2;3-dicarboxylic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 68-73

scholarly journals SiO2 particles effect on the mechanical properties of the starch/PVA blends

2018 ◽  
Vol 16 (36) ◽  
pp. 153-171
Author(s):  
Nahida J. H.
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ultimate Strength ◽  
Thermo Gravimetric Analysis ◽  
Polymer System ◽  
Optical Microscope ◽  
Gravimetric Analysis ◽  
Ratio Increase

The present work studies the mechanical properties of SiO2 μPs, and NPs in St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends at different concentrations (30, 40, 50, and 60 %). DSC and TGA tests were carried out to the samples evolved. The result showed a single glass transition temperature (Tg) for all St /PVA blends that was attributed to the good miscibility of the blends involved. It was found that (Tg) decrease with starch ratio increase. It was seen that (PVA) of (Tg=105 oC); The glass transition temperature which was decrease with starch ratio that was attributed to glass transition relaxation process due to micro-Brownian motion of the main chain back bond. The endothermic peak at 200 oC was attributed to melting point of (PVA). Thermal properties of PVA; and St /PVA blends at different concentration (30, 40, 50, and 60 %) were evaluated by thermo gravimetric analysis (TGA). The analyses were carried out from 20 to 600 oC at 10 oC)/min heating rate in air oxygen atmosphere. The weight loss stages depended on polymer system. The starch addition causing shifting in the second degradation temperature to the higher temperature; which result in overlapping between the two main degradation steps, these result was attributed to the St/ PVA blend compatibility. The mechanical properties results showed a decrease in ultimate strength with starch ratio increase. The ultimate strength of (PVA) was (47 MPa), whereas the ultimate strength of 60 %St/PVA was (11 MPa) and for 30 %St/PVA was the highest ultimate strength of blends involved (26 MPa). SiO2μPs (753.7 nm), and NPs (263.1 nm) were added at different concentrations (1.5, 2, and 2.5 %). 1.5% SiO2μPs, and NPs of the best ultimate strength (69 MPa), (86 MPa) respectively then it was decreased by SiO2μPs, and NPs increase. Optical microscope of the samples involved was investigated. It was concluded the prepared samples were suggested to be used as packaging materials for agriculture application and its ultimate strength could be controlled by SiO2μPs, and NPs addition.

Contribution of Electrostriction in Polyurethane/Polyaniline Blends

2014 ◽  
Vol 1025-1026 ◽  
pp. 697-702
Author(s):  
Darika Jaaoh ◽  
Chatchai Putson ◽  
Nantakan Muensit
Keyword(s):  
Mechanical Properties ◽  
Dielectric Constant ◽  
Glass Transition ◽  
Transition Temperature ◽  
Polymer Blend ◽  
Hard Segment ◽  
Filler Content ◽  
Domain Formation ◽  
Space Charges ◽  
Electrostrictive Polymer

In this work, we present a series of electrostrictive polymer blend that can potentially be used as actuators for a variety of applications. This polymer blend combines an electrostrictive polyurethane with a conductivity polyaniline polymer. The effect of filler content has been investigated. The structures of the blends, the electrical and mechanical properties which affect electrostrictive behavior were studied. The results showed that both dielectric constant and glass transition temperature of the blends increase with increasing polyaniline contents. Moreover, it was noted that space charges distribution and hard-segment domain formation significantly related with electrostrictive coefficient of polymer blend. Therefore, electrostriction behavior in the polymer blends has been demonstrated, and optimal microstructure for electrostriction enhancement has been identified.

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