Effect of interfacial modification on the thermo-mechanical properties of flax reinforced polylactide stereocomplex composites

2020 ◽  
Vol 40 (5) ◽  
pp. 403-408
Author(s):  
Huihui Zhang ◽  
Yuzeng Li ◽  
Gesheng Yang ◽  
Minmin Yu ◽  
Huili Shao
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Hexamethylene Diisocyanate ◽  
Coupling Agents ◽  
Structure And Properties ◽  
Interfacial Modification ◽  
Interfacial Compatibility ◽  
Injection Molded ◽  
Initial Storage ◽  
The Impact

AbstractThe flax and equivalent proportion of poly(L-lactic acid)/poly(d-lactic acid) (PLLA/PDLA) were melt compounded and injection molded to prepare flax reinforced polylactide stereocomplex (sc-PLA) bio-composite, and two different coupling agents, hexamethylene diisocyanate (HMDI) and maleic anhydride grafted polypropylene (MAPP), were used to modify the interface of composite, then the influence of different interfacial modification on the structure and properties of composite was investigated. The results showed HMDI modification decreased the total crystallinity of composite but promoted the formation of stereocomplex crystallites (sc), whereas MAPP modification could improve both the total crystallinity and sc crystallinity. HMDI modification significantly improved the interfacial compatibility of composite, and thereby effectively improved the tensile strength and initial storage modulus of composite. By contrast, the interfacial compatibility of flax/sc-PLA composite was weakened by MAPP modification. Although the tensile properties of flax/sc-PLA/MAPP composite decreased, the impact strength of composite was increased by 12.1% than the unmodified composite. Therefore, the tailored flax/sc-PLA composite with varying properties could be prepared by different interfacial modification.

Effects of Processing Parameters and Nanofillers on Mechanical and Thermal Properties and Morphology of Impact Modified Poly (lactic acid)

2013 ◽  
Vol 1499 ◽  
Author(s):  
Eda Acik ◽  
Ulku Yilmazer
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Impact Strength ◽  
Random Copolymer ◽  
Processing Parameters ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Injection Molded ◽  
The Impact

ABSTRACTTernary nanocomposites of poly (lactic acid) (PLA) were produced by melt blending with two types of elastomers and five types of organoclays to obtain improved mechanical properties such as tensile strength, modulus and impact strength. One of the elastomers is a random copolymer of ethylene and glycidyl methacrylate (E-GMA) and the other one is a random terpolymer of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH). Organically modified montmorillonites (OMMT) were utilized as nanofillers. XRD, DSC, tensile and impact tests were done on the injection molded samples. FTIR, SEM and TEM analyses are still in progress. As preliminary results, thermal analysis showed that the addition of compatibilizers and organoclays does not have a distinct effect on the thermal properties of the composites, and no evidence of nucleation activity of compatibilizers or organoclays was found. For all types of organoclays, the nanocomposites produced with E-GMA exhibited better mechanical properties in comparison to nanocomposites containing E-BA-MAH, especially for the impact strength.

scholarly journals Poly(Lactic Acid)–Poly(Butylene Succinate)–Sugar Beet Pulp Composites; Part I: Mechanics of Composites with Fine and Coarse Sugar Beet Pulp Particles

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2531
Author(s):  
Rodion Kopitzky
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Sugar Beet ◽  
Cell Structure ◽  
Sugar Beet Pulp ◽  
Poly Lactic Acid ◽  
Butylene Succinate ◽  
Fracture Patterns ◽  
Beet Pulp ◽  
The Impact

Sugar beet pulp (SBP) is a residue available in large quantities from the sugar industry, and can serve as a cost-effective bio-based and biodegradable filler for fully bio-based compounds based on bio-based polyesters. The heterogeneous cell structure of sugar beet suggests that the processing of SBP can affect the properties of the composite. An “Ultra-Rotor” type air turbulence mill was used to produce SBP particles of different sizes. These particles were processed in a twin-screw extruder with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) and fillers to granules for possible marketable formulations. Different screw designs, compatibilizers and the use of glycerol as a thermoplasticization agent for SBP were also tested. The spherical, cubic, or ellipsoidal-like shaped particles of SBP are not suitable for usage as a fiber-like reinforcement. In addition, the fineness of ground SBP affects the mechanical properties because (i) a high proportion of polar surfaces leads to poor compatibility, and (ii) due to the inner structure of the particulate matter, the strength of the composite is limited to the cohesive strength of compressed sugar-cell compartments of the SBP. The compatibilization of the polymer–matrix–particle interface can be achieved by using compatibilizers of different types. Scanning electron microscopy (SEM) fracture patterns show that the compatibilization can lead to both well-bonded particles and cohesive fracture patterns in the matrix. Nevertheless, the mechanical properties are limited by the impact and elongation behavior. Therefore, the applications of SBP-based composites must be well considered.

scholarly journals Impact Toughness and Ductility Enhancement of Biodegradable Poly(lactic acid)/Poly(ε-caprolactone) Blends via Addition of Glycidyl Methacrylate

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Kit Chee ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Mohd Faizal Abd Rahman ◽  
Buong Woei Chieng
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Glycidyl Methacrylate ◽  
Interfacial Adhesion ◽  
Tensile Modulus ◽  
Sem Analysis ◽  
Poly Lactic Acid ◽  
Biodegradable Poly ◽  
Interfacial Compatibility ◽  
The Impact

Poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL) blends were prepared via melt blending technique. Glycidyl methacrylate (GMA) was added as reactive compatibilizer to improve the interfacial adhesion between immiscible phases of PLA and PCL matrices. Tensile test revealed that optimum in elongation at break of approximately 327% achieved when GMA loading was up to 3wt%. Slight drop in tensile strength and tensile modulus at optimum ratio suggested that the blends were tuned to be deformable. Flexural studies showed slight drop in flexural strength and modulus when GMA wt% increases as a result of improved flexibility by finer dispersion of PCL in PLA matrix. Besides, incorporation of GMA in the blends remarkably improved the impact strength. Highest impact strength was achieved (160% compared to pure PLA/PCL blend) when GMA loading was up to 3 wt%. SEM analysis revealed improved interfacial adhesion between PLA/PCL blends in the presence of GMA. Finer dispersion and smooth surface of the specimens were noted as GMA loading increases, indicating that addition of GMA eventually improved the interfacial compatibility of the nonmiscible blend.

Structure and properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(L-lactic acid) quasi core/sheath melt-electrospun microfibers

2018 ◽  
Vol 89 (9) ◽  
pp. 1770-1781 ◽  
Author(s):  
Huaizhong Xu ◽  
Benedict Bauer ◽  
Masaki Yamamoto ◽  
Hideki Yamane
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Tensile Tests ◽  
Processing Parameters ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Diffraction Patterns

A facile route was proposed to fabricate core–sheath microfibers, and the relationships among processing parameters, crystalline structures and the mechanical properties were investigated. The compression molded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/poly(L-lactic acid) (PLLA) strip enhanced the spinnability of PHBH and the mechanical properties of PLLA as well. The core–sheath ratio of the fibers was determined by the prefab strip, while the PLLA sheath component did not completely cover the PHBH core component due to the weak interfacial tension between the melts of PHBH and PLLA. A rotational target was applied to collect aligned fibers, which were further drawn in a water bath. The tensile strength and the modulus of as-spun and drawn fibers increased with increasing the take-up velocities. When the take-up velocity was above 500 m/min, the jet became unstable and started to break up at the tip of the Taylor cone, decreasing the mechanical properties of the fibers. The drawing process facilitated the crystallization of PLLA and PHBH, and the tensile strength and the modulus increased linearly with the increasing the draw ratio. The crystal information displayed from wide-angle X-ray diffraction patterns and differential scanning calorimetry heating curves supported the results of the tensile tests.

Mechanical properties of wood flour/poly (lactic acid) composites coupled with waterborne silane-polyacrylate copolymer emulsion

Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 439-447 ◽  
Author(s):  
Ru Liu ◽  
Shupin Luo ◽  
Jinzhen Cao ◽  
Yu Chen
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
High Performance ◽  
Coupling Effect ◽  
Wood Flour ◽  
Flexural Modulus ◽  
Coupling Agents ◽  
Poly Lactic Acid ◽  
Effective Coupling ◽  
Methacryloxypropyl Trimethoxysilane

Abstract Wood flour/polylactic acid (WF/PLA) composites were produced with a WF content of 50% based on three types of waterborne polyacrylate (PA) emulsions including a PA homopolymer emulsion and two types of silane-PA copolymer emulsions as coupling agents. Two silanes were in focus, namely, γ-methacryloxypropyl- trimethoxysilane (silane-1) and vinyltrimethoxysilane (silane-2). The emulsions and the modified WFs were characterized, and the effects were investigated in terms of emulsion type and their loading levels on the mechanical properties of WF/PLA composites. (1) Both types of silanes could be successfully copolymerized with PA to form stable emulsions. (2) With increasing PA loading, the mechanical properties (except for flexural modulus) of the composites increased at first before reaching the maximum values at 4% PA loading and then the properties worsened. However, these values were larger than those of pure composites, especially in cases when PA-silane emulsions were applied. (3) PA modified with silane-1 showed the best coupling effect among all the three PA emulsions. The results can be interpreted that PA emulsions are effective coupling agents for the preparation of high-performance WPCs.

Functionalized Cellulose Nanocrystals for Improving the Mechanical Properties of Poly(Lactic Acid)

2018 ◽  
Author(s):  
Jamileh Shojaeiarani ◽  
Dilpreet Bajwa
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Cellulose Nanocrystals ◽  
Mechanical Test ◽  
Poly Lactic Acid ◽  
Injection Molding Process ◽  
Molding Process ◽  
Dynamic Mechanical ◽  
Uniform Dispersion ◽  
The Impact

Biopolymers are emerging materials with numerous capabilities of minimizing the environmental hazards caused by synthetic materials. The competitive mechanical properties of bio-based poly(lactic acid) (PLA) reinforced with cellulose nanocrystals (CNCs) have attracted a huge interest in improving the mechanical properties of the corresponding nanocomposites. To obtain optimal properties of PLA-CNC nanocomposites, the compatibility between PLA and CNCs needs to be improved through uniform dispersion of CNCs into PLA. The application of chemical surface functionalization technique is an essential step to improve the interaction between hydrophobic PLA and hydrophilic CNCs. In this study, a combination of a time-efficient esterification technique and masterbatch approach was used to improve the CNCs dispersibility in PLA. Nanocomposites reinforced by 1, 3, and 5 wt% functionalized CNCs were prepared using twin screw extrusion followed by injection molding process. The mechanical and dynamic mechanical properties of pure PLA and nanocomposites were studied through tensile, impact and dynamic mechanical analysis. The impact fractured surfaces were characterized using scanning electron microscopy. The mechanical test results exhibited that tensile strength and modulus of elasticity of nanocomposites improved by 70% and 11% upon addition of functionalized CNCs into pure PLA. The elongation at break and impact strength of nanocomposites exhibited 43% and 35% increase as compared to pure PLA. The rough and irregular fracture surface in nanocomposites confirmed the higher ductility in PLA nanocomposites as compared to pure PLA. The incorporation of functionalized CNCs into PLA resulted in an increase in storage modulus and a decrease in tan δ intensity which was more profound in nanocomposites reinforced with 3 wt% functionalized CNCs.

Effects of Coupling Agents on the Mechanical Properties of the Calcium Carbonate-Plastic Composite Packaging Materials

2012 ◽  
Vol 200 ◽  
pp. 321-324 ◽  
Author(s):  
Zhao Xia Wang ◽  
De Gao ◽  
Wen Cai Xu
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Great Influence ◽  
Coupling Agents ◽  
Packaging Materials ◽  
Plastic Composite ◽  
Silane Coupling ◽  
The Impact

Mechanical properties of the calcium-plastic composite have a great influence on the containers. The main factors affecting the mechanical properties are the process and material formulations. This paper mainly describes its impact of the addition of coupling agent. Under the usage of analysis of variance on single factor experiment, the mechanical properties of the calcium carbonate-plastic composite with three different coupling agents (silane, titanate and aluminate) were studied in the same test conditions. The results show that: The type and quantity of the coupling agent effect a lot on the mechanical properties of the composite. The silane coupling agent is the most suitable for calcium carbonate-plastic composite packaging materials, and the compatibility of calcium carbonate and polyethylene can be improved. When the silane coupling agent was at a 2.25 wt. % concentration, the tensile and flexural strength were improved obviously, especially the tensile strength increased by 23.24%, but the impact strength improved slightly.

A method to improve dimensional accuracy and mechanical properties of injection molded polypropylene parts

2017 ◽  
Vol 37 (4) ◽  
pp. 323-334 ◽  
Author(s):  
Shuai Li ◽  
Guoqun Zhao ◽  
Jiachang Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Injection Molding ◽  
Weld Line ◽  
Dimensional Accuracy ◽  
Holding Time ◽  
Dimensional Shrinkage ◽  
Injection Molded ◽  
The Impact

Abstract Gas counter pressure (GCP) technology can impose a reverse pressure to melt and thereby effectively increase the pressure acting on the melt at flow front. Theoretically, it has a potential to solve some defects often occurring in conventional injection molding (CIM) process. This paper designed and manufactured a GCP injection mold. GCP injection molding experiments were conducted. Effects of GCP process on melt flow and density, dimensional accuracy, and mechanical properties of molded samples were investigated. The results showed that GCP process can effectively inhibit the “fountain effect” in melt filling process, decrease the dimensional shrinkage of molded samples, increase dimensional accuracy of samples, and effectively improve impact property of samples. For the samples without weld line, tensile strength and flexural strength of GCP injection molded samples are slightly increased in comparison with those of CIM samples, but for the samples with weld line, GCP process can greatly improve the tensile strength and flexural strength of molded samples. When GCP is 9 MPa and GCP holding time is 10 s, the dimensional accuracy of molded samples without weld line, the tensile strength and flexural strength of the molded samples with weld line all increase up to maximum values. In comparison with CIM samples, the dimensional shrinkage of samples without weld line decreases by 17.2%, the tensile strength and flexural strength of samples with weld line increase by 30.51% and 23.69%, respectively. The impact value of the samples molded by process parameter combination of GCP 9 MPa and GCP holding time 20 s is the highest, and the impact value increases by 18.65%.

Structure and Properties Enhancement in High-Speed Steels upon Primary Solidification of a Melt

2008 ◽  
Vol 144 ◽  
pp. 267-272
Author(s):  
Alexander S. Chaus
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Chemical Elements ◽  
Structural Parameters ◽  
Structure Refinement ◽  
Structure And Properties ◽  
Theoretical Evaluation ◽  
Surface Active ◽  
The Impact ◽  
Toughness Enhancement

In order to exhibit good all-round performance the impact toughness enhancement of cast high-speed steels (HSS) is obligatorily needed. In general, different methods are used commercially to achieve cast structure refinement and, as a consequence, their properties are improved. Introduction into the melt of inoculants particles or surface-active additions is among most beneficial. However, the effect of modifying additions in cast HSS has been studied insufficiently. For this reason the theoretical evaluation and experimental confirmation of the modifying and refining effects of 23 chemical elements in HSS have been carried out. The relationships between the structural parameters and mechanical properties in the M2 and T30 HSS have been established.

scholarly journals The structure and properties of eucalyptus fiber/phenolic foam composites under N-β(aminoethyl)-γ-aminopropyl trimethoxy silane pretreatments

2017 ◽  
Vol 19 (4) ◽  
pp. 116-121 ◽  
Author(s):  
Yufeng Ma ◽  
Chunpeng Wang ◽  
Fuxiang Chu
Keyword(s):  
Mechanical Properties ◽  
Phenolic Resin ◽  
Fiber Composite ◽  
Fiber Surface ◽  
Comprehensive Analysis ◽  
Structure And Properties ◽  
Flame Resistance ◽  
Interfacial Compatibility ◽  
Limited Oxygen ◽  
Trimethoxy Silane

Abstract Eucalyptus fibers were modified with N-β(aminoethyl)-γ-aminopropyl trimethoxy silane to research the fiber surface’s changes and the influence of the treatment on the mechanical properties, flame resistance, thermal conductivity and microstructure of eucalyptus fiber composite phenolic foams (EFCPFs). The results showed that the partial of hemicelluloses, waxes, lignin and impurities from the fiber surface were dissolved and removed. Compared with untreated EFCPFs, the mechanical properties of treated EFCPFs were increased dramatically; The size of cells was smaller and the distribution was more uniform; The thermal conductivities were basically reduced; Especially the ratio of mass loss decreased obviously. However limited oxygen indexs (LOIs) reduced. And the mechanical properties and LOIs of EFCPFs were basically decreased with the increase of eucalyptus fibers. By comprehensive analysis, the results showed that the interfacial compatibility has been significantly improved between eucalyptus fibers and phenolic resin. And the suitable dosage of eucalyptus fibers was about 5%.

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