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Polymer blending is one of the most economical and effective techniques for achieving products with high comprehensive performances. However, the immiscibility between polymers results in a weak interface, which is typically the position where material failure starts when an external force is applied. Therefore, understanding and controlling the interfacial structure are important for controlling the failure behavior of polymer blends and achieving advanced materials. In this study, the related work was performed on a crystal/crystal blend of isotactic polybutene-1 and polyethylene (iPB-1/PE). The results indicated that iPB-1 and PE were partially miscible in a wide temperature window (140–220°C), and the phase separation of iPB-1/PE blends was retarded at 180°C, resulting in an increase in the interfacial thickness and interfacial adhesive strength when iPB-1/PE crystallized at a low temperature. In addition, the iPB-1/high-density PE (HDPE) samples exhibited higher interfacial adhesive strength than the iPB-1/linear low-density PE, which was attributed to the relative streamline chain structure and the wide molecular weight distribution of HDPE and improved the interpenetration, crystallization, and miscibility of iPB-1 and HDPE at the interface. During storage at room temperature, the interfacial adhesive strength of iPB-1/PE decreased because of the spontaneous crystal transition of iPB-1.

Uterine fluid RNA can be used as a test for endometrial receptivity, but there is still no noninvasive sampling method available. The polyvinyl alcohol (PVA) formaldehyde absorbent sponge, a medical bio-absorbent sponge with good water absorption and biophilic properties, can be used to develop a new noninvasive endometrial fluid sampler. This study aims to investigate the toxicity of PVA acetal absorbent sponges on endometrial epithelial cells and its effect on RNA sequencing (RNA-Seq).The experimental group using PVA formaldehyde absorbent sponge was prepared into 0.005%, 0.01% and 0.02% (w/v) suspension, and 0.01%, 0.05% and 0.1% (v/v) extract groups. The control group was only the complete culture medium. Nothing was added to the blank group. In vitro cytotoxicity assay was used to evaluate the survival rate of cells. Eight patients underwent in vitro fertilization treatment in the Reproductive Center of Xiangya Hospital, Central South University from November 2019 to January 2020. The uterine fluid of each patient was aspirated. The experimental group was inhaled with sterile PVA formaldehyde absorbent sponge and then immersed RNA-later solution. The control group was directly injected into the same amount of RNA-later solution. RNA-seq and data analysis was performed later.The vitro cytotoxicity assay showed that in suspension groups, there was no significance difference in cell survival between different co-culture time in 0.005% group (P=0.255). In the 0.01% and 0.02% group, there was no difference at each incubation time within 12 h (all P0.05), but the cell survival rate was decreased at 24 h compared with 0 h (P0.01, P0.05). At the same co-culture time, the cell survival of the 3 concentration gradient groups were significantly lower than that of the control group (all P0.05). The cell viability of the 0.005% concentration group was decreased less than 30% at 24 h, the 0.01% concentration group decreased more than 30% at 12 h, and the 0.02% concentration group was decreased more than 30% at 0 h. For extract groups, there was no significant difference in the survival rate within 6 h in 0.01% concentration group (all P0.05), and the survival rate of 12 h and 24 h was lower than that of 0 h group (both P0.01). In 0.05% group, there was no significant difference at each incubation time within 12 h (all P0.05), but the survival rate at 24 h was lower than that at 0 h (P0.05). There was no significant difference in survival rate at different culture time in 0.1% concentration group (P=0.082). At the same culture time, there was no significant difference in survival rate between 0.01% group and control group at 0, 3 and 24 h (all P0.05). Except for 3 h, the survival rate of 0.05% and 0.1% groups was lower than that of control group (all P0.05), and the decrease was all less than 30%. Uterine fluid RNA-seq showed that there was no significance difference in exonic rate, the detected genes and transcripts of RNA between the experiment groups and the control group (all P0.05).The in vitro cytotoxic of PVA formaldehyde absorbent sponge on human endometrial epithelial cell meet the national standard of the cytotoxic of medical materials. Sampling the uterine fluid with this material does not affect the RNA-Seq results. PVA formaldehyde absorbent sponge is safe and feasible when appling to the noninvasive uterine fluid sampling and RNA sequencing.

Understanding the nature of the active species of the TiCl4/MgCl2 Ziegler–Natta catalyst is special important and challenge. In this work, the pre-treated TiCl4/MgCl2 pre-catalyst by heptane washing (H-Cat) and AlR3 activation (Al-Cat) were prepared and analyzed and then used to conduct butadiene (Bd)-isoprene (Ip) copolymerizations. It was proved that the adsorbed Al compounds on the Al-Cat surfaces after suffering heptane washing increased with the increase in the concentration of alkylaluminium in the pre-catalyst activation process, indicating the stable absorption of Al compounds on the active species and then influencing the catalytic behavior of the active species. Correlated the titanium oxidation state and the catalytic activity, Ti3+ species were more likely the active species for Bd-Ip copolymerization. Ti3+with adsorption of AlR2Cl on Mg adjacent to the Ti species showed reduced activity and produced polymers with high trans-1,4-configuration and relatively high molecular weight (Mw). This study is anxious to provide further understanding on the mechanism of conjugated diene polymerization catalyzed by heterogeneous Ziegler–Natta catalysts. The increase in alkylaluminium concentration during the pre-catalyst activation process changed the chemical surroundings and oxidant state of Ti and then resulted in an obvious increase in adsorbed Al and Ti2+ amount on the catalyst surface, which influenced the activity and stereoregularity for diene polymerization.

A high-purity green-emitting Sr2(Mg,Mn)Al22O36 solid-solution phosphor and its partial doped compound (Sr2(Mg,Mn)Al22O36: Eu2+) were synthesized via solid-state reaction. This solid-solution phosphor shows a green band at 518 nm from Mn2+ instinct 4T1-6A1 transition with a narrow FWHM of 28 nm. This green emission is of high color purity (87.7%) and thermal stable (80% of original intensity at 473 K). However, the emission intensity requires further enhancement due to the limitation of Mn2+ 3d-3d forbidden transition. With a tiny amount of Eu2+ introduced into Sr2(Mg,Mn)Al22O36, the luminescence intensity enormously improved to 260% of that in blank sample due to high-efficient Eu2+-Mn2+ energy transfer, which is induced by a structural confinement effect with Eu2+-Mn2+ distance of 6.225 A. Thus, the EQE of optimal phosphor Sr2Mg0.2Mn0.8Al22O36: 0.01Eu2+ is boosted to 42%. The above results hint that Sr2(Mg,Mn)Al22O36: Eu2+ has promising application potential as a green phosphor for backlighting LEDs in wide-color-gamut display, and this sensitized strategy could be applied for the development of high-performance phosphors.

The composition and structure of polymer largely determine the properties of its final products. As a novel polymer material, the composition, structure, and properties of the isotactic polypropylene/polybutene-1 in-reactor alloy (iPP/iPB alloy) synthesized by sequential two-stage polymerization with Ziegler-Natta catalyst were correlated for the first time in this work. The iPP/iPB alloy was fractionated by temperature rising elution fractionation (TREF) in a broad temperature ranged from −30 °C to 140 °C, and the chain microstructures and sequence distributions of isolated fractions were analyzed by DSC, GPC, 13C-NMR, and FTIR. The iPP/iPB alloy was composed of five components, namely high isotactic PB (iPB, 85.8 wt%), medium isotactic PB (mPB, 5.1 wt%), poly((butene-1)-block-propylene) copolymers (PB-b-PP, 4.1 wt%) which contained PB and PP blocks with different lengths according to the isolation temperature, isotactic PP (iPP, 2.7 wt%), and atactic PB (aPB, 2.3 wt%). Compared to other commercial pipe materials, the iPP/iPB alloy presented outstanding thermal creep resistance and gas permeability resistance, high strength and low deformation at high temperature, and appropriate flexural strength. The roles of PP and PB-b-PP components in the alloy were interpreted. This work is expected to elucidate the potential application of iPP/iPB alloy as pipe materials and provide solutions for the design and synthesis of high performance pipe materials.

The catalytic activity and stereospecificity of olefin polymerization by using heterogeneous TiCl4/MgCl2 Ziegler-Natta (Z-N) catalysts are determined by the structure and nature of active centers, which are mysterious and fairly controversial. In this work, the propylene polymerization kinetics under different polymerization temperatures by using Z-N catalysts were investigated through monitoring the concentration of active centers [C*] with different tacticity. SEM was applied to characterize the catalyst morphologies and growing polypropylene (PP) particles. The lamellar thickness and crystallizability of PP obtained under different polymerization conditions were analyzed by DSC and SAXS. The PP fractions and active centers with different tacticity were obtained with solvent extraction fractionation method. The catalytic activity, active centers with different tacticity and propagation rate constant kp, fragmentation of the catalyst, crystalline structure of PP are correlated with temperature and time for propylene polymerizations. The polymerization temperature and time show complex influences on the propylene polymerization. The higher polymerization temperature (60 °C) resulted higher activity, kp and lower [C*], and the isotactic active centers Ci* as the majority ones producing the highest isotactic polypropylene (iPP) components showed much higher kp when compared with the active centers with lower stereoselectivity. Appropriate polymerization time provided full fragmentation of the catalyst and minimum diffusion limitation. This work aims to elucidate the formation and evolution of active centers with different tacticity under different polymerization temperature and time and its relations with the fragmentation of the PP/catalyst particles, and provide the solutions to the improvement of catalyst activity and isotacticity of PP.

For the solid-solid transformation from form II to form I of isotactic polybutene-1 (iPB), the temperature dependence of form I nucleation and growth was deemed to control the transformation process. However, the relationship between form I formation and form II disappearance in the transformation process is not clear. In this work, the spontaneous crystal transformation from form II to I of iPB with 81 mol% mmmm sequence concentration is studied firstly by tracking the two processes, the decay of form II and the yielding of form I in a wide range of temperature spanning from 0 °C to 50 °C and in a long transformation time ranging from 5 min to 65 days with in situ FTIR and WAXD. Unlike the literature reports, the decay rate of form II is firstly found to be lower than the yielding rate of form I at all studied temperatures, especially at low transition temperature. This is attributed to the amorphous chains which locate near crystal lamella participating into the nucleation of form II. The regular chain folding and growth of iPB form I from amorphous chains containing short isotactic sequences also lead to an increase in crystallinity of form I compared with that of initial form II crystallized at 60 °C. An increase in the annealing temperature results in decrease in crystallinity and increase in lamellae thickness of iPB form I.

Toughening polypropylene (PP) with the good balance of toughness and stiffness was achieved via dynamic vulcanization technology by blending with trans-1,4-poly(isoprene-co-butadiene) rubber (TBIR), a novel copolymer containing trans-polyisoprene blocks with glass transition temperature (Tg) around −70 °C and melting temperature (Tm) around 25–45 °C. Dynamically vulcanized PP/TBIR blends (PP/TBIR DV blends) using sulfur as crosslinking agent was prepared and the phase morphology, glass transition temperature (Tg), crystalline behaviors and mechanical properties of the PP/TBIR DV blends were investigated in details. The PP/TBIR DV blends with 20–25phr TBIR incorporation presented outstanding notched Izod impact strength (12 times higher than that of pure PP) and a high-level tensile strength (about 24 MPa). The TBIR rubber phase was dispersed uniformly in the PP/TBIR DV blends with domain size around 500 nm, and was showed little change with an increase of TBIR content. DMA results demonstrated that the dynamic vulcanization crosslinking enhanced the interface compatibility between PP and TBIR through the increased Tg of both TBIR and PP domains, in which TBIR domains presented more influence. WAXD results showed that the crystallinity of PP decreased slightly, while the crystallinity of TBIR was reduced by 50%. The evolution of morphology and compatibility of the PP/TBIR DV blends were investigated and discussed in detail. Dynamic vulcanization under the optimum curing reaction time definitely hindered the coalescent of the TBIR particle due to the decreased particle adhesion. The co-crosslinking of TBIR and PP caused by dynamic vulcanization improved the compatibility between PP and TBIR obviously.

Heterogeneous TiCl4/MgCl2 type Ziegler-Natta catalysts (supported type Ziegler-Natta catalysts) have been the most important industrial catalysts in polyolefin field due to the high polymerization activity, high stereoselectivity and low preparation cost. This paper reviewed the recent progress on the coordination polymerization mechanism of α-olefins (ethylene, propylene) and conjugated dienes (isoprene, butadiene) including the absorption of TiCl4 on MgCl2 surface, the alkylation and reduction of Ti, the number, valence, structure, model of active centers, the effect of electron donor and alkylaluminum on catalytic mechanism etc. The opportunities and challenges of olefins polymerization catalysed by supported type Ziegler-Natta catalysts were proposed.

Alkylaluminums as one of the most important components of the heterogeneous MgCl2-supported (TiCl4/MgCl2) type Ziegler-Natta catalysts, play significant roles in yielding active species with varied regio- and stereoselectivity. Studying the contribution of alkylaluminums on the conjugated diene isoprene (Ip) and butadiene (Bd) copolymerizations with TiCl4/MgCl2 - alkylaluminum catalysts system is little reported. In this work, effects of various alkylaluminums including triethylaluminium (TEA), triisobutylaluminium (TiBA), diisobutylaluminium hydride (DiBAH) and diethylaluminum chloride (DEAC) on the copolymerization behaviors of Ip and Bd using the TiCl4/MgCl2 - alkylaluminum catalysts system, such as catalytic activity, active center numbers, butadiene incorporation, trans-1,4 stereoselectivity, molecular weight Mw as well as molecular weight distribution Mw/Mn of copolymers were first investigated. TEA with smaller size ethyl groups showed higher copolymerization activity, higher reducing ability and then yielding more active center numbers ([C*]/[Ti]) when compared with TiBA, DiBAH and DEAC. Microstructure of copolymers gradually transformed from the cis-1,4/trans-1,4 mixed structure in the initial polymerization period to the finally high trans-1,4 structure, indicating a transformation of the active center nature during the early polymerization stage, which can be accelerated effectively through the addition of DEAC into the TiCl4/MgCl2-TEA catalyst system. TEA with smaller size ethyl group showed higher transformation rate from the mixed structures of trans-1,4 and cis-1,4 to highly trans-1,4 structure. The active center numbers of the copolymerization systems increased gradually with increasing time until reaching a stable level. The Mw/Mn of copolymers showed interesting evolution with increasing polymerization time from broad distribution with low to medium molecular weight fractions in the initial polymerization stage to relatively narrow distribution with high molecular weight fractions. The contribution of alkylaluminium compounds on the structure of active species which determining the regio- and stereoselectivity of Ip and Bd copolymerization using heterogeneous TiCl4/MgCl2 type catalysts were discussed in details

Higher performance tire tread stocks with lower rolling resistance, higher abrasion, and fatigue resistance are urgent needs considering environmental protection, resource saving, and personal safe...

The molecular weight of a polymer is of prime importance and greatly influences the processing and mechanical properties of the polymer. Trans-1,4-poly(butadiene-co-isoprene) multi-block copolymer rubbers (TBIR) exhibit outstanding fatigue resistance, low heat build-up and good abrasion resistance, and are expected to be desirable candidate for high performance tire. Study on the influence of TBIR with different molecular weights on the structure and properties of TBIR and natural rubber (NR)/TBIR blends is essential to understand its contribution to the greatly improved dynamic properties of the rubber vulcanizates. TBIR with different molecular weights characterized by 1H-NMR, 13C-NMR, GPC, and DSC were highly trans-1,4-copolymers with similar chain sequence distribution and crystalline trans-1,4-polyisoprene (TPI) blocks. The green strength and modulus of TBIR increased with the increasing molecular weight. The NR/TBIR compounds filled with 40 phr carbon black were chemically cured by sulfur for the preparation of NR/TBIR vulcanizates. The compatibility between NR and TBIR, filler distribution, crosslinking bond and density, and properties of NR/TBIR vulcanizates were studied. The NR/TBIR vulcanizates showed increasing tensile strength, hardness, modulus, rebound, abrasion resistance, and flexural fatigue properties with increasing molecular weight of TBIR. Furthermore, they presented significant improvement in flexural fatigue resistance when compared with that of NR vulcanizate. The contribution mechanism of TBIR on the NR/TBIR blends was discussed. The TBIR with a wide range of molecular weight are ideal rubbers for high performance tires.

Research question Does the endometrial aspiration (EA) of ultrasound-invisible fluid immediately preceding embryo transfer affect in vitro fertilization/frozen-thawed embryo transfer (IVF/FET) outcomes? Design A prospective matched cohort study was conducted in 96 women and 96 controls to assess the effect of endometrial aspiration performed immediately before embryo transfer on pregnancy outcomes. This study was carried out at a university-affiliated assisted reproductive medical center between January 2019 and December 2019. Patients were divided into two groups: EA group: cycles with EA of ultrasound-invisible fluid performed before embryo transfer and non-EA group featuring cycles without endometrial aspiration. The EA group was matched by propensity score (PS) with the non-EA group at a ratio of 1:1. The EA group consisted of 99 participants before PS matching and 96 participants after matching. The numbers of subjects in the non-EA group before and after PS matching were 203 and 96, respectively. Results No significant differences were detected in the baseline characteristics and cycle characteristics of the EA and non-EA groups. No significant between-group differences were found in reproductive outcomes in the overall population. Subgroup analysis of blastocyst transfer cycles showed the implantation rate was significantly higher in the EA group (61 women per group; 57.1% vs 40.8%; RR: 1.40; 95%CI: 1.04, 1.88; P=0.022). Live birth rate, clinical pregnancy rate, ongoing pregnancy rate, and multiple pregnancy rate were not different among the groups (P>0.05). Conclusion The endometrial aspiration immediately preceding embryo transfer does not affect IVF/FET outcomes. Interestingly, it could improve the frozen-thawed blastocyst implantation rate. Randomized controlled trials are needed to confirm this result. Study funding This study was funded by the National Key Research and Developmental Program of China (grant number 2018YFC1004800) and the National Natural Science Foundation of China (grant number 8187061497).

BackgroundThe synchrony between the embryo and the receptive endometrium is essential for successful implantation. Therefore, a reliable non-invasive ER prediction method is highly demanded. We aimed to establish a method that could be used to predict endometrium receptivity non-invasively and to evaluate its clinical application potential in patients undergoing IVF.MethodsThe non-invasive RNA-seq based endometrial receptivity test (nirsERT) was established by sequencing and analyzing the RNA of uterine fluid from 48 IVF patients with normal ER. Subsequently, 22 IVF patients were recruited and analyzed the correlation between the predicted results of nirsERT and pregnancy outcomes.Results87 marker genes and 3 hub genes were selected to establish the nirsERT. 10-fold cross-validation resulted in a mean accuracy of 93.0%. A small cohort retrospective observation showed that 77.8% (14/18) of IVF patients predicted with normal WOI had successful intrauterine pregnancies, while none of the 3 patients with displaced WOI had successful pregnancy.ConclusionsnirsERT is potential for a non-invasive, accurate and same cycle testing for ER in reproductive clinic.FundingFunded by the National Natural Science Foundation of China (grant no. 8187061497) and the National Key Research and Developmental Program of China (grant no. 2018YFC1004800).Clinical trial numberChiCTR-DDD-17013375.

With the globe warming, heat stress (HS) has frequently affected animal production. Selenium (Se) is an essential trace element for animals and exerts most of its biological functions through selenoproteins. We previously demonstrated that the damage to C2C12 cells by HS accompanied with the response of selenoprotein encoding genes and proteins. The objective of this study was to investigate whether selenium supplementation (sodium selenite, SS and selenomethionine, SeMet) could alleviate the negative effect of heat stress on the differentiation of C2C12 cells, and interpret the potential corresponding selenoproteins response. The differentiated cells were cultured for 4 and 8 days under different condition: at 37 °C, 41.5 °C and 41.5 °C with 0.5 μmol Se/L SS or SeMet, and the HSP70, cell apoptosis, selenoproteins and cell differentiation-related gene or protein were detected. The result showed that HS up-regulated (P

Most of natural water-soluble polymers are difficult to electrospin due to their specific chain conformation in aqueous solution, which limits their applications. This study investigated the effects of polyethylene oxide (PEO) on the electrospinning of hyaluronic acid (HA) in HA/PEO aqueous solutions. The rheological properties of HA/PEO aqueous solutions showed polymer chain entanglement in HA was the essential factor affecting its electrospinnability. Wide-angle X-ray scattering and differential scanning calorimetry analyses of a PEO crystal showed different crystallization behavior of the PEO chain with different molecular weight, which indicates different interaction with HA. A schematic molecular model has been proposed to explain the effect of PEO on the chain conformation of HA along with the relationship between electrospinnability and chain entanglement. PEO with a relatively high molecular weight with limited crystal formation formed extensive chain entanglements with HA, while PEO with relatively low molecular weight weakened the interactions among HA chains. The findings of this study provide a wide perspective to better understand the electrospinning mechanisms of natural polyelectrolytes and usage in tissue engineering.

Two MgCl2-supported Ziegler-Natta model catalysts were prepared by contacting activated MgCl2 with deficient or excess amount of TiCl4. Ethylene/1-hexene copolymerization with the catalysts was conducted under different 1-hexene feed, and active center concentration of the reaction system was determined by quench-labeling method using thiophene-2-carbonyl chloride as the quencher. The catalytic activity was only moderately enhanced (increment

Filled natural rubber (NR)/cis-1, 4-polybutadiene rubber (BR) blends are commonly used as tire sidewall stocks. However, the incompatibility and mismatched curing rate between NR and BR and selective distribution of fillers in BR phase result in unsatisfied dynamical properties of NR/BR blends. Herein, we have proposed a facile approach to modulate multi-scale structures in NR/BR blends including the polymer and filler network structures by introducing trans-1,4-poly (butadiene-co-isoprene) copolymer (TBIR) with multi trans-1, 4-polyisoprene (TPI) blocks as novel reactive multifunctional compatibilizer. Both DMA and TEM results prove that the incorporation of crystalline TBIR not only improve the compatibility between NR and BR with greatly reduced domain size, but also enhance filler dispersion with reduced filler segregation in BR phase. In addition, the co-vulcanization between NR and BR is enhanced with the incorporation of TBIR which could participate in curing reaction. As a result, NR/BR/TBIR vulcanizates show excellent comprehensive dynamical performances.

Amphiphilic Janus nanosheets with reactive rubber brushes (PBd-silica-PI) were fabricated by using silica nanosheets as templates and by attaching polyisoprene (PI) and polybutadiene (PBd) brushes onto opposite sides. The compatibility between the attached polymer brushes and the rubber matrix accounted for reduced phase domains, revealing as a bicontinuous structure within the PBd-silica-PI Janus nanosheet filled solution styrene–butadiene rubber/natural rubber (SSBR/NR) blends. Although the silica nanosheet templates themselves could act as a reinforcing agent for the rubber materials, as with most silica, in this case, the amphipathy and the co-vulcanization of the reactive polymer brushes with the native polymer matrix enabled the synchronous strengthening and toughening of the rubber blends. When 3 parts per hundred rubber (phr) of Janus nanosheets were incorporated, the tensile strength of the composites was 3-times higher than that of the SSBR/NR blend on its own, and 2 times higher than that of silica nanosheet filled rubber blends. Additionally, the elongation at break of the composites reached a maximum of 470% compared to the original 320% of the SSBR/NR blends on their own.

Multi-block stereoregular copolymer of styrene and isoprene was realized by stereospecific copolymerization with supported titanium Ziegler-Natta catalyst [TiCl4/MgCl2-Al(i-Bu)3] successfully. Effects of initial monomer ratio (Ip/St) on catalyst efficiency (CE) and composition and sequence structure of the as-obtained copolymers were studied. Apparent reactivity ratios, which represent the apparent relative reaction rate of Ip and St, were calculated based on the Kelen-Tudos method. The activity of isoprene (raIp = 11.12) was much higher than that of styrene (raSt = 0.14) under this catalyst system. The copolymers were fractionated by the n-hexane extraction. The nascent copolymers and the fractions were characterized by FT-IR, NMR, DSC and GPC. The soluble fraction of n-hexane extraction were multi-block copolymers with long trans-polyisoprene (trans-PI) segments and single/short isotactic polystyrene(iPS) segments. The insoluble ones were copolymers with long iPS segmets and short trans-PI segments. DSC analysis showed two glass transition temperatures close to each other by adjusting the amount of St in copolymers. The whole copolymers were composed of crystallizable copolymers with different segment length of trans-PI blocks and iPS blocks. This work offers a novel way for stereospecific copolymerization of alpha-olefin and conjugated diene by using traditional supported titanium Ziegler-Natta catalyst.

Aiming at the problem that the influence degree of static and dynamic accuracy of EMA pitch servo mechanism is not clear, this paper analyzes the influence degree of static and dynamic error of EMA pitch servo mechanism based on high-precision pointing system. In terms of static error, based on the static error kinematics model, by establishing the static error probability model and solving the static error model, it is pointed out that the geometric error is the largest factor affecting the static kinematics error. In terms of the influence degree of dynamic error, based on the dynamic error kinematics model, through the establishment of the dynamic error separation process, and based on the test and mechanical experiment platform, it is pointed out that the general trend error is the largest factor affecting the dynamic kinematics error. Through the analysis of the influence degree of static and dynamic kinematic errors, the accuracy improvement direction of the EMA pitch servo mechanism is defined.

Solution-polymerized styrene–butadiene rubber (SSBR) is commonly used as rubber tread stock for high wet-skid resistance, but SSBR suffers from shortcomings including high rolling resistance, unsatisfied abrasion resistance, and fatigue resistance, which triggers great research efforts in pursuing tread stock with balanced performances. Herein, a facile strategy was proposed through introducing novel trans-1,4-poly(butadiene-co-isoprene) rubber (TBIR) into silica-filled SSBR composites. The filler networks and rubber phase structures of SSBR/TBIR blends were investigated in detail. It was found out that TBIR was responsible for the depression of filler flocculation during annealing and vulcanization processes, which will contribute to the improvements of filler dispersion status in SSBR/TBIR vulcanizates. The covulcanization and compatibility of the two domains in SSBR/TBIR blends were also investigated. Consequently, the resultant SSBR/TBIR vulcanizates exhibit excellent integrated properties. Furthermor...