Comparative Study on Properties of PBAT/PBSA Film Modified by a Multi-Functional Epoxide Chain Extender or Benzoyl Peroxide

Poly(butylene adipate-co-terephthalate)(PBAT)and poly(butylene succinate-co-adipate)(PBSA)blend films were prepared with different contents of a multifunctional epoxide chain extender Joncryl ADR-4468(ADR)or benzoyl peroxide(BPO).The long-chain-branching(LCB)introduced by ADR and branched/crosslinked entanglement induced by BPO increased melt elasticity,viscosity and compatibility,as indicated by thermal properties,rheological and morphological analyses.It was found that the elongation at break and the tensile strength were significantly improved,due to the enhancement of compatibility and the interfacial adhesion by the incorporation of ADR or BPO.The best mechanical properties were obtained in PBAT/PBSA/ADR(60/40/0.3)(A4T6A_(0.3))and PBAT/PBSA/BPO(60/40/0.9)(A4T6B_(0.9))films,respectively.With the rapid initiation of chain growth by BPO,it has significantly improved the transparency of the film.ADR and BPO can be used interchangeably in improving the comprehensive properties of PBAT/PBSA films,and it would provide more strategies for developing biodegradable materials for various applications.

Synthesis and characterization of yellow water-borne polyurethane using a diol colorant as extender

A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isophorone diisocyanate(IPDI), polycaprolactonediol(PCLD) and 2,2-dimethylol propionic acid(DMPA) using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline (HENA) as a chain extender.Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate,a series of stable yello...

Silicone Chain Extender for Recycled Polyethylene-terephthalate with Higher Flexibility

To decrease the modulus and increase the mechanical properties of recycled PET by introducing the flexible segments, the recycled polyethylene-terephthalate(PET) was modified by the chain extender produced with 2, 4, 6, 8-tetramethyl-2, 4, 6, 8-tetra(2, 3-epoxypropoxy) propylcyclotetrasiloxane by the hydrosilylation reaction. Different percentages of chain extender were used in order to investigate the effect of chain extender content on the modulus of PET. The dynamic mechanical analysis was performed on PET samples, which showed that Tg of PET was firstly raised by the addition of chain extender and then decreased. Small amplitude shearing test performed on PET samples confirmed that the addition of the flexible segments could remarkably decrease the modulus of PET, which would be helpful for the extrusion process. The entanglements from branches were also influenced by the addition of extender.

Effect of Semen Extender and Storage Temperature on Motility of Ram Spermatozoa

Cryopreservation of ram semen results in low post-thaw survival. Thus, studies were conducted to optimize liquid-storage of chilled semen. In Experiment 1, semen collected from rams (n = 5) was extended using either milk, TRIS (tris[Hydroxymethyl]aminomethane), TEST (N-Tris (hydroxymethyl)-methyl-2-aminoethane sulfonic acid), or CJ-2 (choline-based extender) and stored at either 4℃ and 15℃. All extenders were supplemented with 5% (v/v) egg yolk. In Experiment 2, semen collected from 9 rams was distributed across TRIS or milk extenders supplemented with 5% or 20% (v/v) egg yolk, and 0 or 1% ethylene glycol (EG), during storage for 72 hours at 4℃. The effect of penicillamine, hypotaurine, and epinephrine (PHE) on motility parameters was also evaluated following storage. In Experiment 1, most of the sperm motility parameters were higher after extension, and storage at 4℃ compared with 15℃ (P P in vivo sperm viability and conception rates when using extended, stored semen for artificial insemination of ewes.

Performance of Local Clay-Titanium Dioxide Core-Shell Extender Pigments in Alkyd Paints

The performance of local clay-titanium dioxide core-shell extender pigments in alkyd paints has been studied. The physico-mechanical properties of the prepared alkyd paints were evaluated according to ASTM measurements. The effects of various environmental and corrosive factors on the paints were also studied. The study showed that the alkyd paint samples formulated using the core-shell pigments generally had low specific gravity (1.30 – 1.38), an indication that more of the core-shell pigments can be incorporated into the alkyd paints with considerable cost savings. The dry film thicknesses of the paint samples falls within 0.24 - 0.39 mm, suggesting that the samples will perform well as anticorrosive coatings and their adhesion properties are generally good, showing that they can withstand abrasive and corrosive agents. The core-shell extender pigments formulated paint samples were observed to exhibit the best dust-free, tack-free, and through dry times compared to TiO2 paint formulation. The formulated paint samples generally performed well on exposure to rain and sunlight as well as in distilled water, 2% Na2CO3, and 2% H2SO4 with only TiO2 paint formulation exhibiting rust. The good paint performance characteristics obtainable with the core-shell extender pigments are enough evidence to justify their utilization in the surface coatings industry. The performances of these core-shell extender pigments in alkyd paints have shown that they combine the properties of both the clays and titanium dioxide, and have the potential to overcome their disadvantages.

Preservability of rabbit semen after chilled storage in tris based extender enriched with different concentrations of Propolis ethanolic extract (PEE)

Objective:To maintain semen quality of male rabbits during chilled storage by enrichment the tris based diluent with different concentrations of propolis ethanolic extracts.Methods: Total phenolic and total flavonoid contents, as well as antioxidant activity was determined in propolis ethanolic extract (PEE). The extract was analysed by HPLC for separation and identification of target metabolites. Semen was collected from 10 rabbit bucks, pooled, then divided into five aliquots (each of 500 μL) and diluted each in 5 mL Tris-citric acid-glucose-egg yolk extender (TCGY). The 1st aliquot served as control while PEE was added at concentration of 0.8, 1.2, 1.6 and 2.0 mg/5 mL tris extender in the aliquot 2, 3, 4 and 5 respectively. Diluted semen samples were subjected to cooling at 4℃ for 72 h. Sperm motility, sperm viability, sperm abnormality, sperm membrane integrity and acrosome integrity were evaluated in chilled semen allover the chilling period.Results:The resluts revealed presence of a considerable amount of total phenolic compounds (98.67 mg GAE/g extract) and total flavonoids (70.16 mg CE/g extract) which were parallel to an antioxidant activity assessed as ABTS, DPPH and FRAP (198.65, 180.18 and 306.17 mM TE/g extract respectively). The dominant phenolic acid was chlorogenic acids (3.959 mg/g extract). Other compounds were found in less amounts rosmarinic acid (3.959 mg/g extract), myrcetin (1.946 mg/g extract), kaempferol (1.089 mg/g extract) and apeginin-7-glucoside (1.113 mg/g extract). Obtained results clearly demonstrated that the addition of (1.2-1.6) mg PEE in the chilled extended rabbit semen proved to be beneficial for maintaining semen characteristics compared to control and the addition of 0.8 and 2 mg PEE.Conclusions: The enrichment of rabbit semen tris-basic extender with (1.2-1.6) mg PEE/5 mL tris-extender (as the best and safe concentrations) maintain the sperm characteristics in good condition all over 72 h of chilling.

Dietary selenium supplementation, clarified egg yolk extender and slow cooling improve cryopreserved sperm characteristics of Saanen buck

Objective:To evaluate the effect of cooling rates,selenium supplementation,and three semen extenders on cooled and frozen-thawed Saanen buck sperm.Methods:Twenty Saanen bucks were divided into two groups:the selenium supplemented group and the control group.Ejaculates were collected once weekly by artificial vagina.The first experiment examined the effects of cooling rates and selenium supplementation on semen characteristics of Saanen bucks.Pooled semen was diluted with triladyl extender and split into two aliquots for slow and fast cooling.The second experiment explored the effect of selenium supplementation and semen extenders on post-cryopreserved sperm quality.Ejaculates from each group were divided into three aliquots and diluted with three extenders(i.e.clarified egg-yolk,whole egg yolk,Tris without egg-yolk extenders).All samples were cooled for 2 h at 4℃and frozen at-196℃for 24 h.The sperm characteristics such as sperm motility,acrosome integrity,normal morphology,and viability were evaluated by using a phase-contrast microscope.Results:In the first experiment,all sperm characteristics were significantly increased in selenium supplemented samples when slow cooling was used(P<0.05).In the second experiment,in cooled semen,sperm motility and viability were significantly increased in both clarified egg yolk and Tris without egg yolk extenders in selenium supplemented samples as compared with whole egg yolk extender,respectively(P<0.05).After freezing-thawing,all sperm parameters of selenium supplemented samples in clarified egg yolk extender were significantly greater than those in Tris without egg yolk extender(P<0.05).However,normal morphology and acrosome integrity of selenium supplemented samples in whole egg yolk extender were similar to those of selenium supplemented samples in clarified egg yolk extender.Conclusions:The characteristics of cooled and post-cryopreserved sperm are greater when clarified egg yolk extender is used in semen from selenium supplemented bucks.

Anti-wrinkle Finishing of Cotton Fabrics with Pyromellitic Acid Enhanced by Polyol Extenders

Pyromellitic acid(PMA)has been employed for formaldehyde-free anti-wrinkle finishing on cotton fabrics for its low damage to fibers and absence of phosphorus-containing catalysts.However,the wrinkle resistance performance of fabrics failed to meet the application expectation.In this work,the polyol extenders were introduced into PMA cross-linked cellulose for further improving fabric resilience by a two-step dipping-squeezing-curing method.Eleven polyols were employed as the chain extenders for PMA anti-wrinkle finishing on fabrics,among which sorbitol presented the best chain-spreading effect on wrinkle resistance.After screening the process parameters,the optimum process was obtained as follows.The dosage ratio of PMA to sorbitol was 1∶1,the curing condition was 150-160℃ for 2-3 min.Scanning electron microscopy(SEM),thermogravimetric analysis(TGA)and Fourier transform infrared(FTIR)spectroscopy were employed to characterize the fiber changes during the process.The results showed that the sorbitol incorporation could facilitate the remelting and redissolution of PMA on fiber surface.During the curing process,sorbitol could form ester linkages between PMA molecules and improve the fiber resilience.The treated samples presented excellent washing durability,and the wrinkle recovery angle A_(w)was still 265.1°after 10 washes,which was close to that of 1,2,3,4-butane tetracarboxylic acid(BTCA)but with lower tearing load loss.The results provide new insights for the application of PMA in formaldehyde-free anti-wrinkle finishing on cotton fabrics.

Characterization and Utilization of Eziulo Clay as an Extender in Emulsion Paint Formulations

A series of emulsion paint samples were prepared using Eziulo clay as an extender, commercial whiting, and titanium dioxide (TiO2). The clay that was calcined at 850oC and sieved to three particle sizes (0.075, 0.100 and 0.150 mm) was incorporated into emulsion paints at varying amounts ranging from 5% - 32% of the total extender and pigment in the paints. Poly (vinyl acetate) was used as the binder while distilled water served as the solvent. The Eziulo clay which consisted mostly of silica (63.30%), alumina (19.40%), and iron (III) oxide (2.10%) had the following properties: pH (6.67), specific gravity (2.47) and oil absorption (34.30 g/100 g clay). The colour and solubility of the clay in dilute hydrochloric acid, acetic acid, sodium chloride solution, methanol and distilled water were generally unaffected either in the cold or when heated expect for the slight solubility observed in methanol. The clay formulated paint samples exhibited higher viscosity (7.0 - 7.80 poise) than the paint sample without Eziulo clay (6.60 poise). Conversely, the pH and specific gravity of the paint sample without Eziulo clay were higher than those of paint sample containing the clay. The surface and hard dry times of the formulated paint samples were greater than that of the paint sample without Eziulo clay. The determined surface dry times were within the range, 16 - 18 min, irrespective of clay content and particle size. The hard dry times of the formulated paint samples were found to reverse with increases in clay content. The paint dry film flexibility was unaffected by the incorporation of clay, irrespective of the amount and clay particle size. The emulsion paint dry films exhibited decreases in film adhesion to substrates with increases in clay content, and increases in film adhesion with increases in clay particle size. The paint dry films did not exhibit any chalking tendency, were resistant to fungal attack, and passed the water drop test. The present study has demonstrated the utility of Eziulo clay in emulsion paint formulations which should justify its use in the surface coatings industry.

Effects of Bifunctional Chain Extender on the Crystallinity and Thermal Stability of PET

Effects of bifunctional chain extender on the crystallinity and the thermal stability of PET were studied in this work. Results of Infrared substractive spectrum indicated that one oxazoline ring of 2,2’-bis(2-oxazoline) (BOZ) reacted with one carboxyl in PET to generate a blocked PET chain with an oxazoline ring, which then reacted with one carboxyl in second PET to form an extended chain. The intrinsic viscosity (IV) of extended PET would increase from 0.61 of initial PET to 0.80 when the addition of BOZ was 0.52 wt%. Furthermore, when BOZ was used with hydroxyl-addition-type chain extender 2,2’-(1,4-phenyl)bis(4H-3,1-benzoxazin-4-one) (BNZ) or chain end modifier phthalic anhydride (PA), IV of chain extended PET would be 0.83 and 0.97 respectively. DSC results showed that chain extending would result in a decrease in crystallinity of PET. Comparing with initial PET, the intrinsic viscosity loss of the chain extended products would be smaller after multi-melting processing.

Extender Properties of Some Nigerian Clays

The extender properties of some Nigeria clays have been studied. The local clays were characterized using X-ray fluorescence and scanning electron microscope. The physico-chemical properties of the clays were evaluated using ASTM standards. The physico-chemical characterization of the local clays gave the following results: specific gravity (2.54 and 2.49), oil absorption (51.0 and 59.0 g/100g), refractive index (1.7 and 2.0) and pH (5.1 and 4.8) for Nsu and Ihitte-Uboma clays respectively. Compositional analysis showed that the clays consisted predominantly of silica (SiO2) and aluminium oxide (Al2O3) in high proportions with the other constituents present in very small proportions. The clays were stable to heat and insoluble in toluene, methanol, ethanol, 2-propanol, chloroform and hydrochloric acidexcept for their slight solubility in acetic acid. The colour of the clays was not affected in cold or when heated except for slight colour change observed in the presence of hydrochloric acid when heated. The particle morphology of the clays indicated the presence of sub-angular platelet of varying sizes. The optimum calcination temperature of the clays was determined to be 850°C for use in oil-based paints. The clays can be used in gloss paints, rubber and plastic composites and as an adsorbent with improved properties.

Laboratory Evaluation of Asphalt Containing Recycled Plastic as a Bitumen Extender and Modifier

Recent interest in recycling and reuse of waste plastic has resulted in a dramatic increase in the evaluation of waste plastic as an extender and/or modifier of bituminous binder for asphalt production. Although significant field trials of waste plastic modified asphalt have been reported in Australia since 2017, no laboratory evaluation of the effects of these products on the engineering properties of binder and asphalt has been published. In this research, two commercially available recycled waste plastic products were evaluated in the laboratory. One product is intended to be plastomeric while the other is intended to be elastomeric in nature. Compared to unmodified viscosity grade bitumen and acid modified multigrade, the recycled plastic products increased the viscosity and softening temperature of the binder and introduced significant elastic recovery. Following dry-mixing into asphalt, the recycled plastic products were associated with improved mixture deformation resistance and increased mixture stiffness. However, the mixtures containing recycled plastic were also associated with an increase in moisture susceptibility and their fatigue lives were not significantly different to those of the control mixtures. Further research is recommended to better understand the modest reduction in moisture damage resistance associated with recycled plastic, as well as the digestion of recycled plastic via the dry-mixing process.

电脑操作超级助手——Filebox Extender

在电脑的各种操作中，我们用得比较频繁的是“另存为”和“打开”这两个操作。但Windows的设计不够人性化，使用这两个操作时，我们常常会展转于硬盘的各级目录。难道就不能让操作更为简洁吗？有了Filebox Extender就可以让你的操作一步到位！

A Corpus-Based Study on General Extenders in Different Genres in American English

This article investigates general extenders in American English,using a more than one-billion-word corpus(COCA)classified by different genres.In this study,the differences and frequencies of general extenders in different genres are displayed.The study also illustrates the tendency of the use of general extenders in American English from 1990 to 2020.Moreover,the salient features of general extenders used in different genres are observed.The study can provide some practical implications for the use of general extenders for second language learners.

Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(CE) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of CE affects the hydrogen bonding organization within PCUs and their mechanical properties.To investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1,4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the CE chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different CEs was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of CE can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

带Range-Extender纯电动汽车动力系统设计

引入Range-Extender概念,阐述纯电动汽车前期开发过程中动力系统参数的设计过程,旨在为纯电动汽车动力系统参数开发提供参考。

Extending homogeneous fluidization flow regime of Geldart-A particles by exerting axial uniform and steady magnetic field

The homogeneous/particulate fluidization flow regime is particularly suitable for handling the various gas–solid contact processes encountered in the chemical and energy industry.This work aimed to extend such a regime of Geldart-A particles by exerting the axial uniform and steady magnetic field.Under the action of the magnetic field,the overall homogeneous fluidization regime of Geldart-A magnetizable particles became composed of two parts:inherent homogeneous fluidization and newly-created magnetic stabilization.Since the former remained almost unchanged whereas the latter became broader as the magnetic field intensity increased,the overall homogeneous fluidization regime could be extended remarkably.As for Geldart-A nonmagnetizable particles,certain amount of magnetizable particles had to be premixed to transmit the magnetic stabilization.Among others,the mere addition of magnetizable particles could broaden the homogeneous fluidization regime.The added content of magnetizable particles had an optimal value with smaller/lighter ones working better.The added magnetizable particles might raise the ratio between the interparticle force and the particle gravity.After the magnetic field was exerted,the homogeneous fluidization regime was further expanded due to the formation of magnetic stabilization flow regime.The more the added magnetizable particles,the better the magnetic performance and the broader the overall homogeneous fluidization regime.Smaller/lighter magnetizable particles were preferred to maximize the magnetic performance and extend the overall homogeneous fluidization regime.This phenomenon could be ascribed to that the added magnetizable particles themselves became more Geldart-A than-B type as their density or size decreased.

A guidance and control design with reduced information for a dual-spin stabilized projectile

In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constraint of an actuator,uncertainties in aerodynamic parameters and measurements,and control system complexity.Owing to the fairly high rotation speed,the dynamic model of this missile is strongly nonlinear,uncertain and coupled in pitch,yaw and roll channels.A theoretical equivalent resultant force and uncertainty compensation method are comprehensively used to realize decoupling of pitch and yaw.In response to the strong nonlinear and time-varying characteristics of the dynamic system,the quasi-linear model whose parameters are obtained by interpolation of points selected as the segmentation points in the trajectory envelope,is used for calculation in each step.To cope with the system uncertainty caused by model approximation,parameter uncertainty and ballistic interference,an extended state estimator is used to compensate the output feedback according to the test ballistic angle.In order to improve the tracking efficiency and ensure the tracking error convergence with only translational motion information,the virtual guide point,whose derivative is deduced according to the Lyapunov principle,is calculated in real time according to the projection relationship between the real-time position and the reference trajectory,and a virtual line-of-sight angle and the backstepping method are used for the design of the guidance and control system.In order to avoid the influence of control input saturation on the guidance and control performance due to the actuator limitation and improve the robustness of the system,an anti-saturation compensator is designed according to the two-step method.The feasibility and effectiveness of the path-following controller is verified through closed-loop flight simulations with measurement,control,and condition uncertainties.The results indicate that the designed controller can converge to the reference path and evidently decrease the distance between the impact point and target under different uncertainties.

2D DOA Estimation of Coherent Signals with a Separated Linear Acoustic Vector-Sensor Array

In this paper, a two-dimensional(2D) DOA estimation algorithm of coherent signals with a separated linear acoustic vector-sensor(AVS) array consisting of two sparse AVS arrays is proposed. Firstly,the partitioned spatial smoothing(PSS) technique is used to construct a block covariance matrix, so as to decorrelate the coherency of signals. Then a signal subspace can be obtained by singular value decomposition(SVD) of the covariance matrix. Using the signal subspace, two extended signal subspaces are constructed to compensate aperture loss caused by PSS.The elevation angles can be estimated by estimation of signal parameter via rotational invariance techniques(ESPRIT) algorithm. At last, the estimated elevation angles can be used to estimate automatically paired azimuth angles. Compared with some other ESPRIT algorithms, the proposed algorithm shows higher estimation accuracy, which can be proved through the simulation results.

Occurrence of K1 and K2 serotypes and genotypic characteristics of extended spectrumβ-lactamases-producing Klebsiella pneumoniae isolated from selected hospitals in Malaysia

Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia.Methods:A total of 192 K.pneumoniae isolates were collected and subjected to antibiotic susceptibility,hypermucoviscosity test and multiplex PCR to detect the presence of K1-and K2-serotype associated genes.Multilocus sequence typing(MLST)was performed on ESBL-producing K.pneumoniae isolates presented with K1 and K2 serotypes,followed by phylogenetic analysis.Results:A total of 87 out of 192(45.3%)of the K.pneumoniae isolates collected were ESBL producers.However,only 8.3%(16/192)and 10.9%(21/192)of the total isolates were detected to carry K1-and K2-serotype associated genes,respectively.Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype(P=0.196).However,they were significantly associated with hypervirulent,as demonstrated by the positive string test(P<0.001).MLST analysis revealed that ST23 as the predominant sequence type(ST)in the K1 serotype,while the ST in the K2 serotype is more diverse.Conclusions:Although the occurrence of ESBL-producing isolates among the hypervirulent strains was low,their coexistence warrants the need for continuous surveillance.MLST showed that these isolates were genetically heterogeneous.