Poly Propylene Carbonate Research Articles

Analysis of Crosstalk Effects for Ternary Logic MWCNT Bundled Through Silicon Vias

This article presents a technique to improve the crosstalk effects in ternary coupled through silicon vias (TSVs). The effects of crosstalk are investigated in TSVs using multi walled carbon nanotube (MWCNT) as metallic liner and polymers such as polyimide, polypropylene carbonate (PPC), benzocyclobutene (BCB) as dielectric liners. The circuit model for coupled TSVs driven by ternary inverter is utilized to analyze the various crosstalk issues. The HSPICE tool is utilized to develop the proposed TSVs. The crosstalk issues for the MWCNT TSVs are investigated and compared to single walled CNT (SWCNT) TSVs. Moreover, the power, power delay product (PDP) and energy delay product (EDP) are analyzed and compared to SWCNT TSVs. All the performances are also studied for different TSV pitches. The coupled TSVs with BCB show high performance for the large pitch values. Moreover, it is noticed that the coupled TSVs with BCB at 5000 μm TSV pitch improved the performance up to 40.03% over the SWCNT TSVs.

Incorporation of Modified Graphene Nanoplatelets for Development of Bio-based Shape Memory Polymer of Polypropylene Carbonate (PPC)/Polycaprolactone (PCL)

Incorporation of Modified Graphene Nanoplatelets for Development of Bio-based Shape Memory Polymer of Polypropylene Carbonate (PPC)/Polycaprolactone (PCL)

Sandwich-Structured Composite Polymer Electrolyte Based on PVDF-HFP/PPC/Al-Doped LLZO for High-Voltage Solid-State Lithium Batteries

High-performance solid-state lithium-metal batteries (SSLMBs) require solid electrolytes displaying outstanding electrochemical stability, excellent ionic conductivity, and high Li+ ion transference number. On top of these, it should also be compatible with the electrodes applied and functionable under room temperature. To achieve these, a solution-casting technique is proposed herein to prepare a flexible composite polymer electrolyte (CPE), which is equipped with a high ionic conductivity and Li+ ion transference number, concurrently applicable in the construction of high-voltage solid-state Li batteries. The proposed CPE, which is made up of poly(vinylidene difluoride-co-hexafluoropropylene) (PVDF-HFP)/polypropylene carbonate (PPC) blend with an Al-doped Li7La3Zr2O12 (Al-LLZO) filler, was sandwiched between PVDF-HFP/PPC–lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) skin layers with SN plasticizer added. This formulation of PVDF-HFP/PPC/Al-LLZO/LiTFSI/SN was abbreviated as sandwich-PPA in our study. Such configuration permits notable resistance reduction at the electrode–electrolyte interface while suppressing Li dendrite growth throughout the robust charging–discharging process. This can be attributed to the excellent performance of the sandwich composite electrolyte membrane, which promises high ionic conductivity (ca. 4.04 × 10–4 S cm–1) and a high Li+ ion transference number (ca. 0.583) at room temperature. A CR2032 coin cell, which is assembled with Al2O3-C@NCA/Sandwich-PPA/Li, delivered a high specific capacity (186.20 mAh g–1 at 0.1C at room temperature), along with its excellent rate performance and cycle stability (discharge capacity of 126.23 mAh g–1; capacity retention of 80.03% after 100 cycles at a rate of 0.5C at room temperature). This verified the potential of our novelty-formulated solid-state electrolyte to secure excellent performance of SSLMBs.

Biodegradable composites of poly(propylene carbonate) mixed with silicon nitride for osteogenic activity of adipose-derived stem cells and repair of bone defects.

Absorbable polymers have attracted increasing attention in the field of bone regeneration in recent years for their degradation. Compared with other degradable polymers, polypropylene carbonate (PPC) has several advantages such as biodegradation and relatively cheap raw materials. Most importantly, PPC can degrade into water and carbon dioxide totally which does not give rise to local inflammation and bone resorption in vivo. However, pure PPC has not presented excellent osteoinductivity properties. In order to enhance the osteoinductivity of PPC, silicon nitride (SiN) was employed due to its excellent mechanical properties, biocompatibility and osteogenesis compared with the other common materials such as hydroxyapatite and calcium phosphate ceramics. In this study, composites of PPC mixed with different contents of SiN were prepared successfully (PSN10 with 10 wt% SiN content, and PSN20 with 20 wt% SiN content). The characterization of the composites suggested that PPC mixed with SiN evenly and PSN composites presented stable properties. The results in vitro revealed that the PSN20 composite possessed satisfactory biocompatibility and exerted better osteogenic differentiation effects on adipose-derived stem cells (ADSCs). In particular, the PSN20 composite accelerated the healing of bone defects better and degraded with the process of bone healing in vivo. Overall, the PSN20 composite exhibited better biocompatibility, induced osteogenic differentiation of ADSCs and promoted healing of bone defects, due to which the PSN composite is considered as a potential candidate for treating bone defects in the field of bone tissue engineering.

An automated software development for analysis of the morphological-tensile property relationship in egg shell bio-based particulate composites using machine learning algorithms

This work explored the importance of quantitative observation through imaging methods of optical and electron microscopies on the mechanical properties of particulate polymeric composites. Egg shell powder (ESP) reinforced polypropylene carbonate (PPC) polymeric composites with different filler weight percentage (wt.%) from 1 to 5 wt.% were considered. A cost-effective Image Analysis Software (IAS) was developed to extract black particles from the original optical images. During this process, the optimal image can be reproduced based on its originality by controlling the threshold values from 0.1 to 0.6 in real time situation. Using one-dimensional (1D) Gaussian distribution analysis, the authentication of the particle distribution data was studied and linked to the tensile strength of the composites. The mean value of the particle area collected from the left and right side of the scattered curves has a significant effect on the tensile strength of the composites. The proposed model was validated by comparing the predicted statistical results with the measured tensile strength for different wt.% of ESP composites. From the results obtained, a close agreement of 99% accuracy was observed between the experimental results and the proposed model for the tensile strength of the composites. The innovative study provides more practical and quantitative knowledge on improved particulate polymeric composites, in addition to the detection of failure processes through optical/electron microscopic examination of images. Evidently, the proposed cost effective, accurate and less stressful model can be employed by several composite-based industries to correlate the tensile strengths of particulate polymeric composites with their morphological properties.

Synthesis of environmental-curable CO2-based polyurethane and its enhancement on properties of asphalt binder

The polyurethane (PU) modified asphalt prepared by melting method has poor thermal storage stability and the PU used is normally synthesized from non-renewable petrochemical resources. This paper aims to explore the feasibility of preparing environment-friendly PU and using it to enhance asphalt properties. Environmental-curable CO2-based PPC-PU and ordinary BDO-PU was prepared with poly propylene carbonate diol (PPC) and Butanediol (BDO), respectively. Fourier transform infrared spectroscopy and thermogravimetric analysis were used to examine their chemical compositions and thermal characteristics. Then, these two types of PU were used to modified asphalt and the chemical functional groups, microstructure, storage stability, viscosity, low temperature, and high temperature properties of various modified asphalts were tested. The findings revealed that the prepared PPC-PU and BDO-PU had good thermal stability and the decomposition temperature was above 200 °C. PPC-PU modified asphalt can be gradually cured at natural environment to form a crosslinking network, and the curing rate can reach 86.23% in 15 days. In addition to the low temperature performance, other properties of PPC-PU modified asphalt were gradually improved with the extension of curing time. Compared with BDO-PU modified asphalt, PPC-PU modified asphalt has superior storage stability, low temperature, and high temperature properties. It is concluded that the environmental-curable PPC-PU can improve performance of asphalt while consuming CO2. This research offers a fresh concept for producing of green PU modified asphalt.

Cold Sintering–a New Approach to Reprocess Composite Electrolytes in All-Solid-State Lithium-Ion Battery

As all-solid-state lithium-ion batteries (ASSBs) start to dominate the electronic market, studies regarding to recycling spent batteries remain limited and uncomprehensive. The primary factor causing the failure of batteries is the loss of structural integrity in solid-state electrolytes (SSEs) with limited degradation in the active properties. A promising reprocessing strategy is to repair the fragmented structure. Herein, solid-state composite electrolytes, Li7La3Zr2O12 with polypropylene carbonate (PPC) and lithium perchlorate (LLZO–PPC–LiClO4), are reprocessed by cold sintering process. The low sintering temperature allows co-sintering ceramics with polymers and salts, thereby enabling densifying composite structures. Reprocessed LLZO–PPC–LiClO4 show densified microstructures with ionic conductivities above 10−4 Scm−1 at room temperature and good long-term stability at 0.1 mA h cm−2 over 2000 hours. The cold sintered full-cell, Li4Ti5O12/ reprocessed LLZO–PPC–LiClO4/LiFePO4, exhibits impressive electrochemical performance.

Effect of Different Comonomers Added to Graft Copolymers on the Properties of PLA/PPC/PLA-g-GMA Blends

The melt-free radical grafting of glycidyl methacrylate (GMA) onto poly (lactic acid) (PLA) with styrene (St), α-methylstyrene (AMS), and epoxy resin (EP) as comonomers in a twin-screw extruder was used to prepare PLA-g-GMA graft copolymers. The prepared graft copolymers were then used as compatibilizers to prepare PLA/PPC/PLA-g-GMA blends by melt blending with PLA and polypropylene carbonate (PPC), respectively. The effects of different comonomers in the PLA-g-GMA graft copolymers on the thermal, rheological, optical, and mechanical properties and microstructure of the blends were studied. It was found that the grafting degree of PLA-g-GMA graft copolymers was increased to varying degrees after the introduction of comonomers in the PLA-g-GMA grafting reaction system. When St was used as the comonomer, the grafting degree of the PLA-g-GMA graft copolymer increased most significantly, from 0.8 to 1.6 phr. St as a comonomer also most improved the compatibility between PLA and PPC, and the haze of the blends was reduced while maintaining high transmittance. In addition, the PLA-g-GMA graft copolymer with the introduction of St as a comonomer significantly improved the impact toughness of the blends, while the thermal stability and tensile strength of the blends remained largely unchanged.

Biodegradable microplastics impact the uptake of Cd in rice: The roles of niche breadth and assembly process

Biodegradable microplastics (MPs) can impact the accumulation of cadmium (Cd) by plants, however, its mechanisms have not been fully understood. In this study, two biodegradable MPs, polypropylene carbonate (PPC) and polylactic acid (PLA), were used to examine their influences on the uptake of Cd in rice plants. Results showed that PPC significantly reduced the accumulation of Cd in rice root and aerial part, whereas PLA increased the Cd concentrations in rice root. The random forest analysis revealed that the bacterial biomarkers enriched by two MPs were different at genus level. Niche breadths were significantly reduced under Cd stress, and PPC alleviated this environmental pressure for entire bacterial community, whereas PLA reduced the niche breadth for whole community and abundant taxa, which was further verified by co-occurrence network and normalized stochasticity ratio model. The abundant taxa of group PPC were primarily governed by deterministic process while rare taxa were more driven by stochastic process. Structural equation model and Mantel analysis identified that the niche breadth imposed a strong selection on Cd accumulation after co-exposure. This study reveals the underlying mechanism of assembly process and niche breadth of rice rhizosphere microbiome on Cd accumulation by rice plants.

Preparation of carbon dioxide, propylene oxide, and norbornene dianhydride terpolymers catalyzed via dinuclear cobalt complexes: Effective improvement of thermal, mechanical, and degradation properties

Dinuclear cobalt complex salen[Co(III)TFA]2 (salen = 3,5-di-tert-butyl- salicylaldehyde-3,3ˊ-diaminobiphenylamine, TFA = trifluoroacetic acid) was synthesized and used to catalyze the preparation of novel polycarbonate terpolymers (PPCEA) of carbon dioxide, propylene oxide and norbornene dianhydride. The results showed high catalyst reactivity under mild conditions, generating a polymer with maximum Mn of 2.3 × 105 g/mol and a narrow molecular weight distribution PDI of 1.01. The 5% thermal weight loss temperature (Td,-5%) of PPCEA can reach 310 °C, which is 150 °C higher than conventional polypropylene carbonate. In addition, its mechanical properties were also improved. The tensile strength increased from10.8 MPa to 22.8 MPa, and elongation at break decreased from 430% to 106%. The polymer has good degradability as well. Furthermore, based on the polymerization results, the corresponding polymerization mechanism is proposed in this paper.

Remarkable enhancement in thermal performance of polypropylene carbonate by using exfoliated boron nitride nanosheets

Biodegradable polymers are expected to replace traditional petroleum-derived polymers to meet environmental needs. However, its poor heat resistance limits its wide use. Intensive efforts have been taken to enhance the heat resistance, but the results are less than satisfactory and involve complicated steps. In this work, a facile carboxymethylcellulose-boron nitride nanosheets (CMC-BNNS) are used to realize the heat resistance enhancement modification of biodegradable poly (propylene carbonate) (PPC). Sodium carboxymethylcellulose (CMC-Na) is used to exfoliate and functionalize hexagonal boron nitride (h-BN) for the first time. The obtained CMC-BNNS with a uniform size after differential centrifugation can be stably dispersed in water and organic solvents. Benefit from the surface multifunctional group and 2D splinting effect of CMC-BNNS, the resultant PPC/CMC-BNNS composites not only possess superior heat resistance, but also display better thermal conductivity and dynamic mechanical properties compared with PPC/BN composites. The glass transition temperature (Tg) of the of PPC/CMC-BNNS composites with 2.5 wt% CMC-BNNS loading content greatly increases to 39.19 °C from 27.39 °C of neat PPC. This work provides a novel route for exfoliating 2D materials and heat resistance modification of biodegradable polymers.

Unzipping polymers significantly enhance energy flux of aluminized composites

This paper describes a new approach to enhancing the energy delivery rate of pyrotechnics by employing an unzipping polymer. The basic strategy is to localize the heat feedback to just near the reaction front by driving the endothermic chemistry of unzipping. This should then liberate gas near the flame front and propel particles away from the burning surface, to minimize agglomeration and sintering. In this study, polypropylene carbonate (PPC) is employed to load 90 wt% Al and CuO nanoparticles (NPs) via direct ink-writing. The results show a >1500% faster energy release rate from the aluminothermic reaction compared to a conventional polymer binder. Through in-operando microscopy, we observed a 6X thinner flame front and smaller combustion products, revealing significantly lower agglomeration of Al NPs with the unzipping polymer. Fast-heating Time-of-Flight Mass Spectrometry confirms that the unzipping polymer decomposes to low-molecular-weight gasses at a relatively low temperature, which significantly reduces the sintering of Al NPs. The thinner flame implies that heat feedback to the unreacted materials is more localized and drives the endothermic unzipping reaction for gas generation. This study provides a new approach to substantially increasing the energy release rate of nanoscale metallic fuels.

Degradation characteristics of biodegradable film and its effects on soil nutrients in tillage layer, growth and development of taro and yield formation

This study investigated the degradation characteristics of different biodegradable film and its effects on soil nutrients in tillage layer, growth and development of taro and yield formation. Field experiment with biodegradable films, including poly-(butylene adipate-co-butylene terephthalate) PBAT, (poly-carbon dioxide) PCO2, (poly propylene carbonate) PPC, as well as common mulch film (CK1) and uncovered mulch film (CK2) were conducted on Longxiang taro in 2020 and 2021 respectively. The degradation rate of the three biodegradable films was PBAT > PPC > PCO2. Compared with CK1, the alkali-hydrolyzed N of PBAT at the growth stage and fruiting stage significantly increased in 2020 and 2021, respectively (both, P < 0.05). The average content of available P of PPC at seedling stage was higher than that in PCO2, and CK1 was significantly decreased compared with that in CK2 (all, P < 0.05). The content of soil available K and organic matter in different growth stages of taro in all film mulching treatments were decreased in comparison to CK2. Moreover, compared with CK2, PCO2 biodegradable film significantly increased plant height at seedling and growth stage, stem diameter at growth stage, and leaf area index at fruiting stage (all, P < 0.05). Similarly, the yield of mother and filial bulbs of PPC, PCO2 and PBAT were significantly higher than those of CK2 in 2020 and 2021, respectively (all, P < 0.05). However, no significant differences were found in starch, polysaccharide and protein contents among different treatments. The three biodegradable films, especially PCO2, can significantly affect soil nutrient content, promote plant growth and improve taro yield.

Quantitative assessment of particle dispersion in polymeric composites and its effect on mechanical properties

In this work, an automated image analysis tool is developed to establish quantitative correlations between the particle/cluster size distribution and the mechanical properties of particle reinforced polymer composites (PRPC).This automated image analysis tool is developed within python programming software to process and analyze the microstructural images of the polymer-based composite materials. The spent coffee bean powder (SCBP) reinforced poly-propylene carbonate (PPC) polymer composite with differing wt.% of the filler is selected for the analysis. Detailed statistical analysis of the microstructural images reveals that ‘clustering of clusters’ is also presented in addition to the most commonly reported ‘clustering of particles’, and the distribution of particle/clusters is bimodal. Based on these findings, an effective volume fraction for the filler material is proposed to mainly capture the agglomeration effect. With this effective volume fraction, the standard rule-of-mixture model correctly captures the experimentally measured tensile strength and modulus as a function of filler wt.%. Further, the applicability of this effective volume fraction for other theoretical models is also analyzed. The detailed statistical analysis of the microstructure and the proposed effective volume fraction helps to develop a deeper quantitative understanding of the PRPC than the conventional qualitative correlation of microstructural features with the properties and failure processes.

Research and Application of Polypropylene Carbonate Composite Materials: A Review.

The greenhouse effect and plastic pollution caused by the accumulation of plastics have led to a global concern for environmental protection, as well as the development and application of biodegradable materials. Polypropylene carbonate (PPC) is a biodegradable polymer with the function of “carbon sequestration”, which has the potential to mitigate the greenhouse effect and the plastic crisis. It has the advantages of good ductility, oxygen barrier and biocompatibility. However, the mechanical and thermal properties of PPC are poor, especially the low thermal degradation temperature, which limits its industrial use. In order to overcome this problem, PPC can be modified using environmentally friendly materials, which can also reduce the cost of PPC-based products to a certain extent and enhance their competitiveness in terms of improving their mechanical and thermal properties. In this paper, we present different perspectives on the synthesis, properties, degradation, modification and post-modification applications of PPC. The modification part mainly introduces the influence of inorganic materials, natural polymer materials and degradable polymers on the performance of PPC. It is hoped that this work will serve as a reference for the early promotion of PPC.

Preliminary Findings of Polypropylene Carbonate (PPC) Plastic Film Mulching Effects on the Soil Microbial Community

The farmland residual film pollution caused by traditional PE film has an adverse impact on crops and the environment. Polypropylene carbonate (PPC) film is a fully biodegradable film that can alleviate “white pollution”. In this study, the soil physicochemical properties and the composition and function of the soil community of FM (PPC film mulching) and CK (no film) treatments were determined to explore the effect of PPC film mulching on soil and the soil microbial community. Furthermore, the microorganisms at different time periods during the degradation of PPC mulch film were also analyzed. The results showed that film mulching increased soil pH but decreased the contents of EC and SOC, and there was no significant difference in the contents of AP and AK. The relative abundance of the phyla Acidobacteria was increased with film mulching, and the relative abundance of the genera MB_A2_108 also increased in the film mulched soil. Among the soil physicochemical properties, pH and SOC were the most important factors leading to changes in the composition of the bacterial and fungal communities. PPC film mulching had no significant effect on soil microbial community abundance and diversity. In addition, Pseudomonas, Flavobacterium, and Rhizobacter were dominant in the degradation of PPC film. Our research results provide a scientific theoretical basis for soil safety and the large-scale use of PPC biodegradable mulching films and a research foundation for the degradation of PPC plastics.

Investigation of Crosstalk Issues for MWCNT Bundled TSVs in Ternary Logic

The investigation of crosstalk issues for coupled through silicon vias (TSVs) in ternary logic is presented in this study. The crosstalk issues are analyzed for coupled TSVs utilizing multi-walled carbon nanotube (MWCNT) as conductive filler, and polymer liners such as polyimide, polypropylene carbonate (PPC), benzocyclobutene (BCB) as insulating materials. For the coupled TSVs, the electrical equivalent circuit model is used to investigate the crosstalk which is driven by the ternary inverter. Based on the Hewlett simulation program with integrated circuit emphasis (HSPICE) simulations, the effects of crosstalk such as functional and dynamic crosstalk for proposed TSVs are compared with single-walled CNT (SWCNT) TSVs. Furthermore, the other performance parameters such as power dissipation, power delay product (PDP), and energy delay product (EDP) are investigated. The crosstalk effects of the proposed model are also examined for various TSV heights. It is noticed that the BCB based coupled MWCNT TSVs provide a significant improvement in crosstalk at reduced TSV height. It is also noticed that the proposed TSVs improved the overall performance up to 30.21% compared to the SWCNT based TSVs. Hence, the MWCNT based TSVs with BCB liner are most suitable for ternary logic integrated circuits (ICs) over the conventional TSVs.

Facile synthesis, high fluorescence and flame retardancy of carbon dots

• New synthesis of carbon dots (CDs) with high quantum yield of 86% is demonstrated. • Integration of CDs and polymers forms highly fluorescent supraballs and patterns. • CDs show superior flame retardancy for highly flammable polymeric foams and fibers. • Molecular dynamics simulation is conducted for flame retardancy behavior of CDs. Facile strategy enabling the fabrication of carbon dots (CDs) with favorable performance useful for various applications is highly desirable. Here, we report the fabrication of highly fluorescent carbon dots (CDs) towards sensitive metal ion detection, brightly fluorescent printing pattern, as well as green flame retardants for synthetic polymeric materials. CDs are synthesized by solvothermal treatment of polypropylene carbonate (PPC) with ethylenediamine, and the quantum yield of CDs could increase from 30% to 86% by further adding trace of citric acid. The abundant functional groups on the surface of CDs allow CDs well incorporated into polymers to form CD-loaded polystyrene (PS) microspheres, which are employed to construct fluorescent supraballs via triphase microfluidic technique and used as “inks” for uniform fluorescent patterns. Interestingly, the resultant CDs show good flame retardancy for highly flammable polymeric foams and fibers. The CDs surpass previously reported flame-retardant additives, to show excellent combustion resistance that the addition of 20 wt% CDs causes 75% decrease in the peak of heat release rate (P-HRR) for polyurethane (PU) foams. Significantly, a molecular dynamics simulation process for PU/CDs combustion is constructed. This work may spur the preparation and application of high-performance carbon-based nanomaterials.

Laser-Induced Interdigital Structured Graphene Electrodes Based Flexible Micro-Supercapacitor for Efficient Peak Energy Storage.

The rapidly developing demand for lightweight portable electronics has accelerated advanced research on self-powered microsystems (SPMs) for peak power energy storage (ESs). In recent years, there has been, in this regard, a huge research interest in micro-supercapacitors for microelectronics application over micro-batteries due to their advantages of fast charge–discharge rate, high power density and long cycle-life. In this work, the optimization and fabrication of micro-supercapacitors (MSCs) by means of laser-induced interdigital structured graphene electrodes (LIG) has been reported. The flexible and scalable MSCs are fabricated by CO2-laser structuring of polyimide-based Kapton ® HN foils at ambient temperature yielding interdigital LIG-electrodes and using polymer gel electrolyte (PGE) produced by polypropylene carbonate (PPC) embedded ionic liquid of 1-ethyl-3-methyl-imidazolium-trifluoromethansulphonate [EMIM][OTf]. This MSC exhibits a wide stable potential window up to 2.0 V, offering an areal capacitance of 1.75 mF/cm2 at a scan rate of 5.0 mV/s resulting in an energy density (Ea) of 0.256 µWh/cm2 @ 0.03 mA/cm2 and power density (Pa) of 0.11 mW/cm2 @0.1 mA/cm2. Overall electrochemical performance of this LIG/PGE-MSC is rounded with a good cyclic stability up to 10,000 cycles demonstrating its potential in terms of peak energy storage ability compared to the current thin film micro-supercapacitors.

Remarkable Enhancement in Thermal Performance of Polypropylene Carbonate by Using Exfoliated Boron Nitride Nanosheets

Remarkable Enhancement in Thermal Performance of Polypropylene Carbonate by Using Exfoliated Boron Nitride Nanosheets