TPS Content Research Articles

Preparation and Characterization of PBAT/OTPS Blend Films with Epoxidized Soybean Oil (ESO) for Eco-friendly Packaging Application

The application of starch-based films is limited by the poor water vapor barrier and mechanical properties. In this study, plasticized octenyl-succinated corn starch (OTPS) was mixed into Poly (butylene adipate-co-terephthalate) (PBAT) with various concentration (0/0.25/0.5/0.75 wt%) of epoxidized soybean oil (ESO) to enhance the mechanical properties and the hydrophobicity of blends. Tensile Strength and elongation at break of PBAT/OTPS film was slightly strengthened as the added ratio of ESO raised to 0.5 wt%, yet lessened again in 0.75 wt% sample. The yield strength and elastic modulus were highest in 0.25wt% of ESO added. In thermal properties, the melting temperature (Tm) and crystallization temperature (Tc) were highest at ESO 0.25 and the maximum degradation temperature (Tmax) of components of the films were developed as ESO added. Also, it has been proved that the addition of hydrophobic substances reduces the hydrophilicity of the film by contact angle. This suggests the use of epoxidized oil for preparing films based on high TPS content allows obtaining enhanced interfacial adhesion. This study confirmed that ESO acts as a compatibilizer between OTPS and PBAT to improve the mechanical properties and hydrophobicity of the sample. The sample containing 0.5wt% of ESO was the most suitable for packaging application.

Influence of PBS, PBAT and TPS content on tensile and processing properties of PLA-based polymeric blends at different temperatures

PLA-based blends were prepared with different ratios of PBS, PBAT and TPS additives to adjust their mechanical and processing properties in various temperatures ( − 20 °C, 0 °C, 20 °C, 40 °C). Biodegradable polymeric specimens were obtained by preliminary extrusion and subsequent injection molding. Tensile properties, e.g., tensile strength, elongation at break, Young’s modulus and yield strength were evaluated. Next, melt flow and melt volume ratios were established. Softening, glass transition, cold crystallization and crystallization temperatures were determined with the use of the DSC method. Heat Deflection Temperatures for 1.8 MPa (HDT A) and 8 MPa (HDT C), as well as Vicat Softening Temperatures at 10 N (VST A) and 50 N (VST B), were examined. The manufacturing method was intentionally simplified to eliminate the need for additional mixture’s modification with compatibilizers. Each of the ductile compounds enhanced the deformability of PLA—most significantly in the case of PBAT and TPS, while at the same time reducing its tensile strength. The effect of the test conditions (strain rate and temperature) on the specimens was evaluated in order to determine the stability of the manufactured blends in dependence on these parameters.

Investigation of sugar signaling behaviors involved in sucrose-induced senescence initiation and progression in N. tabacum

Sugar is involved in initiating leaf senescence. However, its regulatory role, especially as a signal in the senescence process, is unclear. Therefore, this study was designed to illustrate how sugar stimulates the onset of leaf senescence and controls sugar homeostasis through the T6P-SnRK (sucrose non-fermenting (SNF)-related kinase) and HXK (hexokinase) signaling pathways. We used a leaf disc system detached from fully expanded leaves of Nicotiana tabacum cv. K326 and designed a time-course study (days 3, 5, 7, and 9) with exogenously gradient concentrations (0, 30, 60, 90, 120, and 150 mM) of sucrose (Suc) treatment to identify how Suc application affects sugar metabolism and induces senescence. Our results revealed that early decreases of Fv/Fm and increases in electrolyte leakage responded to Suc on day 3. Furthermore, a substantial increase in lipid peroxidation and up-regulated expression of senescence marker genes (NtSAG12) (except 60 mM on day 3) responded sequentially by day 5. The glucose, G6P, and HXK contents were first induced by Suc on day 3 and then repressed from day 5 to day 7. However, exogenous Suc treatment significantly improved the TPS content and the subsequent precursor T6P from day 3 to day 7. Following exogenous Suc treatments, the transcript level of NtSnRK1 was markedly down-regulated from day 3 to day 7. On the other hand, a linear regression analysis demonstrated that the T6P-NtSnRK1 signaling pathway was strongly associated with senescence initiation, and was accompanied by membrane degradation and NtCP1/NtSAG12 up-regulation by day 3. The T6P-NtSnRK1 signaling pathway experienced membrane and chloroplast degradation by day 5. HXK functioned as a metabolic enzyme promoting Glc-G6P and as a Glc sensor, accelerating the initiation of senescence through the HXK-dependent pathway by repressing PSII by day 3 and the senescence process through the Glycolytic pathway by day 7. These physiological, biochemical, and molecular analyses demonstrate that exogenous Suc regulates T6P accumulation, inducing senescence through the NtSnRK signaling pathway. These results illustrate the role of Suc and the transition of the sugar signaling pathway during the progression of senescence initiation.

Safety evaluation and hypolipidemic effect of aqueous-ethanol and hot-water extracts from E Se tea in rats

E Se tea, processed by the fresh leaves of Malus toringoides (Rehd.) Hughes, is a traditional herbal tea with various human benefits. The present study was aimed to evaluate the toxicity and hypolipidemic effect of aqueous-ethanol extract (EE) and hot-water extract (WE) from E Se tea. Eight main chemical constituents in EE and WE were respectively identified and quantified by UHPLC-HRMS/MS. EE is rich in TPC and TFC, while WE had higher TPS content. Both EE and WE exhibited strong antioxidant activity with no significant difference. The acute toxicity study revealed that the LD50 values were higher than 5000 mg/kg, while both WE and EE had no significant adverse effect in rats by subacute toxicity assay. However, the triglyceride (TG) content in experiment groups (male) and highest doses groups (female) significantly decreased. Furthermore, the hypolipidemic effect of WE and EE were performed on high fat diet induced hyperlipidemic rats. The result exhibited that either WE or EE could effectively regulate lipid droplet accumulation in liver, and reduce the adipocyte size. These results demonstrated that these two extracts from E Se tea could be regarded as a potential functional dietary supplement in preventing and treating diet induced metabolic diseases.

Cellulose nanofibrils reinforced PBAT/TPS blends: Mechanical and rheological properties

Poly(butylene adipate-Co-terephthalate)/thermoplasticized starch PBAT/TPS blends are among the most produced biodegradable plastic for wide application packaging, sharing more than 20% of the global production capacity of bioplastics. However, this class of material suffers from poor mechanical strength in comparison of neat PBAT, especially when the TPS content exceeds 30 wt%. Aiming at enhancing the mechanical performance of PBAT/TPS blends while maintaining relatively high TPS content, cellulose nanofibrils (CNFs) was incorporated into the TPS phase using twin screw extrusion. The effects of CNFs content on the microstructure, mechanical properties, melt-rheology and humidity absorption were investigated. An enhancement in the tensile strength and modulus was noted with the inclusion of CNFs, with optimal performance attained at 8 wt% of CNFs. A narrowing in the distribution of the TPS nodules within the PBAT matrix was also observed with the addition of CNFs, which is expected to be on the origin of the main evolution in the mechanical, rheological and humidity observed. Because of the availability of CNFs, biodegradability and facile processability, the ternary PBAT-TPS-CNFs blends might contribute to improve the performance of this class of biodegradable bioplastic.

Synthesis of vinyl ester resin-carrying PVDF green nanofibers for self-healing applications

Self-healing on the engineering applications is smart, decisive research for prolonging the life span of the materials and the innovations have been mounting still smarter. Connecting to advancements in self-healing carriers, in altering the chemical structure by optimizing the brittleness for self-healing performance and introducing the bio-degradability, for the first time TPS was blended to PVDF for the synthesis of nanofibers, as carriers of a vinyl ester (VE) resin (medication), by the coaxial electrospinning technique. TPS was mechanically mixed with PVDF base polymer and optimized the TPS content (10 wt%) based on mechanical performance. The novel nanofibers were characterized via field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy, X-ray diffraction, thermal, moisture analysis, and a mechanical line with FESEM and energy-dispersive X-ray analysis studied the self-healing. The TPS/PVDF fibers having hydrogen bonding and increased the crystallinity (40.57 → 44.12%) and the diameter (115 → 184 nm) along with the surface roughness of the fibers with increasing the TPS content. Microanalysis presented the flow-out of the VE resin at the scratched parts in the pierced fibers; interestingly, after some time, the etched part was cured automatically by the curing of the spread resin. Mechanical stretching of the nanofibers in the tensile tests up in the plastic region showed a decrement in the elasticity (TPS/PVDF fibers) and an increment in the brittle nature (cured VE resin) with the increase in Young’s modulus at each stretching, clearly elucidating the healing performance.

PLLA and cassava thermoplastic starch blends: crystalinity, mechanical properties, and UV degradation

The effect of the addition of cassava thermoplastic starch on the general properties and the photodegradation behavior of poly(L-lactic acid) (PLLA) was evaluated by blending PLLA with TPS in different weight percentages (5, 10, 15, 20 and 25 wt%). The blends were studied through differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical properties. All the studies were performed before and after the photo-degradation in a climatic chamber. It was found that TPS was immiscible with PLLA and reduced Tg, Tm, and Tcc and influence Xc of PLLA, indicating an interaction of the TPS phase with the PLLA matrix, probably due to plasticizer migration. The tension test showed a decrease in the mechanical resistance of the blends, especially at the lowest TPS content; however, an increase in TPS lead to an increase in ductility. On the other hand, the UV degradation resistance was higher for the blends than for L100, possibly due to the protective effect of glycerol. It was concluded that the films obtained were fully biobased and biodegradable with higher UV resistance than the PLLA and with similar ductility.

Study on the performance of new TPS high viscosity modifier on its modified asphalt

In order to study the effect of a new TPS high viscosity modifier on the performance of its modified asphalt, a new type of TPS high viscosity modified asphalt with 3%, 8%, 13% and 18% content will be prepared, SBS modified asphalt and Japanese TPS modified asphalt were selected for comparison, high temperature and low temperature indexes were tested respectively, and the modification effect of the new TPS high viscosity modifier was verified through comparative analysis, and the more suitable dosage was determined. The results show that with the increase of the new TPS content, the performance of asphalt has been improved. When the content of the new TPS reaches 13%, the indicators of high-viscosity asphalt have fully met the requirements of the specification; By comparing the performance of each high-viscosity asphalt, and combining the requirements of high-viscosity asphalt and Japanese TPS. For the comparison between high-viscosity modifiers, the recommended dosage of this new TPS is between 13% and 18%.

Rheological, mechanical and morphological properties of poly(butylene adipate-co-terephthalate)/thermoplastic starch blends and its biocomposite with babassu mesocarp

Poly (butylene adipate-co-terephthalate)/thermoplastic starch (PBAT/TPS) blends and a PBAT/TPS/babassu mesocarp biocomposite were prepared by melt mixing in a torque rheometer at different processing temperatures (150, 170, 190 °C). Tensile test specimens were obtained by hot pressing. Torque rheometry indicated that molecular weight decreased with increasing processing temperature and TPS content in the blend, and this decrease was more intense with babassu mesocarp addition. PBAT mechanical properties were hardly affected by processing temperature while those of the blends decreased with thermoplastic starch content. Overall, increasing processing temperature led to lower mechanical properties, particularly at 190 °C. Fiber addition led to higher modulus and lower strength and elongation at break than the corresponding blend at all processing temperatures investigated. The differences observed on blend morphology as a function of processing temperature were minor. Some adhesion between TPS and PBAT is observed but adhesion between polymer matrix and babassu fibers is essentially non-existent.

Mechanical and thermal properties of wood fibers reinforced poly(lactic acid)/thermoplasticized starch composites

ABSTRACTThermoplasticized starch (TPS) filled poly(lactic acid) (PLA) blends are usually found to have low mechanical properties due to poor properties of TPS and inadequate adhesion between the TPS and PLA. The purpose of this study was to investigate the reinforcing effect of wood fibers (WF) on the mechanical properties of TPS/PLA blends. In order to improve the compatibility of wood with TPS/PLA blends, maleic anhydride grafted PLA (MA‐g‐PLA) copolymer was synthesized and used. TPS, TPS/PLA blends, and WF reinforced TPS/PLA composites were prepared by twin‐screw extrusion and injection molded. Scanning electron microscope and crystallinity studies indicated thermoplasticity in starch. WF at two different weight proportions, that is, 20% and 40% with respect to TPS content were taken and MA‐g‐PLA at 10% to the total weight was chosen to study the effect on mechanical properties. At 20% WF and 10% MA‐g‐PLA, the tensile strength exhibited 86% improvement and flexural strength exhibited about 106% improvement over TPS/PLA blends. Increasing WF content to 40% further enhanced tensile strength by 128% and flexural strength by 180% with respect to TPS/PLA blends. Thermal behavior of blends and composites was analyzed using dynamic mechanical analysis and thermogravimetric analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46118.

Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

Abstract In this work, low density polyethylene (LDPE)/plasticized starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young’s modulus and tensile strength) improved ostensibly. The Young’ modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior.

Morphology and rheological properties of compatibilized low‐density polyethylene/linear low‐density polyethylene/thermoplastic starch blends

ABSTRACTMorphology and rheological properties of low‐density polyethylene/linear low‐density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) blends are experimentally investigated and theoretically analyzed using rheological models. Blending of LDPE/LLDPE (70/30 wt/wt) with 5–20 wt % of TPS and 3 wt % of PE‐grafted maleic anhydride (PE‐g‐MA) as a compatibilizer is performed in a twin‐screw extruder. Scanning electron micrographs show a fairly good dispersion of TPS in PE matrices in the presence of PE‐g‐MA. However, as the TPS content increases, the starch particle size increases. X‐ray diffraction patterns exhibit that with increase in TPS content, the intensity of the crystallization peaks slightly decreases and consequently crystal sizes of the blends decrease. The rheological analyses indicate that TPS can increase the elasticity and viscosity of the blends. With increasing the amount of TPS, starch particles interactions intensify and as a result the blend interface become weaker which are confirmed by relaxation time spectra and the prediction results of emulsion Palierne and Gramespacher‐Meissner models. It is demonstrated that there is a better agreement between experimental rheological data and Coran model than the emulsion models. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44719.

Effect of PHB on the properties of biodegradable PLA blends

AbstractBlends of biodegradable polymers polylactic acid/thermoplastic starch/polyhydroxybutyrate (PLA/TPS/PHB) were prepared using a twin-screw extruder. The TPS content was constant (50 %) and the PHB content in the blends was gradually changed from 0 mass % to 20 mass %. TPS was prepared by melting, where a mixture of native starch, water and glycerol was fed into the twin-screw extruder. Average temperature of extrusion was 180 °C and the concentration of glycerol was 40 mass %. Influence of the PHB concentration in the blend and that of the processing technology on the mechanical and rheological properties of the PLA/PHB composition containing TPS were studied. Mechanical properties were measured 24 h after the film and monofilament preparation and also after the specific storage time to study the effect of storage on the properties. The results indicate that differences in morphology strongly influence the mechanical properties of the studied materials with identical material composition.

Study on ternary low density polyethylene/linear low density polyethylene/thermoplastic starch blend films.

In this work, low-density polyethylene/linear low-density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) films are prepared with the aim of obtaining environmentally friendly materials containing high TPS content with required packaging properties. Blending of LDPE/LLDPE (70/30 wt/wt) with 5-20 wt% of TPS and 3 wt% of PE-grafted maleic anhydride (PE-g-MA) is performed in a twin-screw extruder, followed by the blowing process. Differential scanning calorimetric results indicate starch has more pronounced effect on crystallization of LLDPE than LDPE. Scanning electron micrograph shows a fairly good dispersion of TPS in PE matrices. Fourier transfer infrared spectra confirm compatibility between polymers using PE-g-MA as the compatibilizer. Storage modulus, loss modulus and complex viscosity increase with incorporation of starch. Tensile strength and elongation-at-break decrease from 18 to 10.5 MPa and 340 to 200%, respectively when TPS increases from 5 to 20%. However, the required mechanical properties for packaging applications are attained when 15 wt% starch is added, as specified in ASTM D4635. Finally 12% increase in water uptake is achieved with inclusion of 15 wt% starch.

The Effect of Citric Acid on the Mechanical Properties of Thermoplastic Tapioca Starch/High Density Polyethylene/Natural Rubber Blends

Effects of citric acid on the mechanical properties of thermoplastic tapioca starch/high density polyethylene/natural rubber (HDPE/NR/TPS) blends were investigated. The ratio between HDPE/NR was fixed at 70/30 and used as a matrix system. TPS loadings with and without modification with citric acid (CA) were varied from 0% to 30wt%. Mechanical and physical properties of blends were evaluated as a function of TPS loadings modified with and without CA. The tensile strength, Young’s modulus and elongation at break were found to decrease with increasing TPS content. However an improvement in the tensile strength for TPS modified with CA at 5%, 10% and 20% TPS loadings was observed. The degree of TPS adhesion and dispersion in HDPE/NR blends were determined by scanning electron microscope (SEM).Keywords; HDPE/NR/TPS, citric acid, tensile properties, morphology.

Preparation and Properties of Compatibilized Poly(Butylenesadipate-Co-Terephalate)/Thermoplastic Starch Blends

Poly (butylenesadipate-co-terephalate) (PBAT) was modified by melt grafting glycidyl methacrylate (GMA) in the presence of benzoyl peroxide (BPO) in a Haake mixer; and the various properties of blends of PBAT/thermoplastic starch (TPS) using GMA-grafted PBAT (PBAT-g-GMA) as compatibilizer were investigated. The blends comprising TPS content ranged from 20wt% to 50wt%. Thermal properties and thermal stability were characterized with DSC and TGA, respectively. The morphologic results indicated that the interfacial adhesion of PBAT/TPS blends was improved by PBAT-g-GMA. In comparison with the uncompatibilized blends, the tensile properties of compatibilized blends were significantly enhanced, particularly at a high content of TPS (i.e., 40wt% and 50wt%).

Formulation-properties versatility of wood fiber biocomposites based on polylactide and polylactide/thermoplastic starch blends

This article discusses the interrelation between formulation, processing, and properties of biocomposites composed of a bioplastic reinforced with wood fibers. Polylactide (PLA) and polylactide/thermoplastic starch blends (PLA/TPS) were used as polymeric matrices. Two grades of PLA, an amorphous and a semicrystalline one, were studied. TPS content in the PLA/TPS blends was set at 30, 50, and 70 wt%. Two types of wood fiber were selected, a hardwood (HW) and a softwood (SW), to investigate the effect of the fiber type on the biocomposite properties. Finally, the impact of different additives on biocomposite properties was studied with the purpose to enhance the bioplastic/wood fiber adhesion and, therefore, the final mechanical performance. The biocomposites containing 30 wt% of wood fibers were obtained by twin-screw extrusion. The properties of the biocomposites are described in terms of morphology, thermal, rheological, and mechanical properties. Furthermore, the biocomposites were tested for humidity and water absorption and biodegradability. An almost 100% increase in elastic modulus and 25% in tensile strength were observed for PLA/wood fiber biocomposite with the best compatibilization strategy used. The presence of the TPS in the biocomposites at 30 and 50 wt% maintained the tensile strength higher or at least equal as for the virgin PLA. These superior tensile results were due to the inherent affinity between the matrices and wood fibers improved by the addition of a combination of coupling and a branching agent. In addition to their outstanding mechanical performance, the biocomposites showed high biodegradation within 60 days. POLYM. ENG. SCI., 54:1325–1340, 2014. © Her Majesty the Queen in Right of Canada 20131

Effects of polyethylene‐grafted maleic anhydride as a compatibilizer on the morphology and tensile properties of (thermoplastic tapioca starch)/ (high‐density polyethylene)/(natural rubber) blends

AbstractEffects of polyethylene‐grafted maleic anhydride as a compatibilizer on the tensile properties of (high‐density polyethylene)/(natural rubber)/(thermoplastic tapioca starch) (HDPE/NR/TPS) blends were investigated. The ratio of HDPE/NR was fixed at 70/30, and these materials were blended with TPS in concentrations varying from 5 to 30% by using a Haake Rheomix 600 mixer. Two series of HDPE/NR/TPS blends were prepared, i.e., with and without compatibilizer. Morphology and tensile properties of the HDPE/NR/TPS blends were evaluated as a function of TPS loading. The tensile strength and elongation at break decreased with the increase of TPS content. However, an improvement in the tensile strength was obtained for compatibilized blends as compared to uncompatibilized blends. The degrees of TPS adhesion and dispersion in HDPE/NR blends were revealed by scanning electron microscopy (SEM). Results showed that a smaller‐sized dispersed phase was achieved for compatibilized blends as compared to that for their uncompatibilized counterparts. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers

Preparation and Properties of Modified Starch with Dimethyl Sulfoxide/Soy Protein Isolates Composites

Dimethyl sulfoxide (DMSO) was added to the starch by melting processing. It was studied respectively that DMSO content effected on mechanical properties, flowabilities, water resistance properties, scanning electron micrographs (SEM) of DMSO-starch (TPS)/DMCS-soy protein isolates (DMCSSPI) materials. SEM results indicated that the crystalline of starch is destructed and the starch granules transferred to a continuous amorphous phase. It was found that the DMSO could more effectively restrain the retrogradation than the plasticizers, due to the stronger hydrogen bonds. For TPS/DMCSSPI composites, the increase of TPS content could make its water resistance properties worse. However, with DMSO content increase, its elongation at break and toughness could be enhanced.

Comparison of sorbitol and glycerol as plasticizers for thermoplastic starch in TPS/PLA blends

AbstractThis article investigates the structure and properties of thermoplastic starch/PLA blends where the TPS phase is plasticized by sorbitol, glycerol, and glycerol/sorbitol mixtures. The blends were prepared using a twin‐screw extruder where starch gelatinization, water removal, and dispersion of TPS into a PLA matrix were carried out sequentially. The plasticizers were added to starch in the first stage of the extruder to allow complete starch gelatinization. The PLA was added at mid‐extruder and thoroughly mixed with the TPS. The plasticizer concentration was varied from 30 to 42% and the TPS content was varied from 27 to 60% on a weight basis. In all investigated blends, the PLA formed the continuous phase and the TPS was the dispersed phase. The viscosity, blend morphology, tensile mechanical properties as well as the thermal properties of the materials were measured. It was found that the glycerol/sorbitol ratio has an important effect on the blend properties. Finer blend morphologies, higher tensile strength and modulus but lower crystallization rate were found for the sorbitol plasticized blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011