SBS改性沥青

介绍了沥青的特性，改性沥青的种类与性能，以及丁苯嵌段共聚物改性沥青的相容性，溶胀性，分散性等方面的研究进展，并提出了发展建议。     

Dynamic and static properties of SBS triblock copolymer and their blends

By using a dynamic testing method (Rheovibron), it has been established that for a pure triblock copolymer (styrene-butadiene-styrene, SBS), the morphology is composed of a continuous phase, a dispersed phase and an interphase. The predominance of the phase depends upon whether the polymer is cast from a good or poor solvent for each block. For the blends of SBS with PS and PBd, the interphase occupies a greater fraction as indicated by the fact that its corresponding molecular relaxation temperature range is much broader (10°–80°C) than that of pure SBS (60°–80°C). If the blends of SBS with its corresponding homopolymers are heated at 140°C for 45 min, the fraction of the interphase increases significantly and the onset of molecular relaxation is lowered to ?10°C. The viscosities of SBS and their blends are measured by both dynamic and static methods. Complex viscosities calculated from the dynamic method show transitions similar to those of storage moduli. Viscosities at different temperatures from these two methods are superimposed onto master curves.     

Preferential plasticization of SBS triblock copolymer

Thermoplastic rubbers made of triblock copolymers of styrene-butadiene-styrene in commercial formulations are commonly used in conjunction with petroleum extender oils, in order to reduce the melt viscosity of the rubber during its processing. These mineral oils contain known quantities of paraffinic-naphthenic and aromatic molecules, which in turn are preferably absorbed by the rubbery and glassy phases respectively, affecting selectively the copolymer domain structure and thus the rheological and mechanical properties. Using a plasticizer, the melt viscosity of the system is reduced due to the plasticization of the phases, as expected. The melt rheological transition temperature shown by the unplasticized block copolymer is still present in the oil extended formulations. The flow activation energy is affected by the temperature, type and content of plasticizer. For temperatures lower than the rheological transition temperature the aromatic oil gradually weakens and destroys the polystyrene aggregates and the paraffinic oil induces a greater segregation of the polystyrene aggregates. At temperatures above the rheological transition temperature the behaviour of the two is similar because the flow is homogeneous.     

Miscibility study of polycarbonate and SBS triblock copolymer blends

Polymer blends of Polycarbonate (PC) and Styrene-Butadiene-Styrene triblock (SBS) have been investigated. SBS copolymers have four different styrenic contents, three of which are linear SBS. PC and PS blends are partially miscible as revealed by dynamic mechanical analysis with two clear Tgs near 100–150°C. On the contrary, PC/SBS blends have only one Tg with a left shoulder. Based on the PS domain model of pure SBS, we suggest a micelle model based on the structure when the micelle and absorb PC in the PC/SBS blends. The micelle plays an important role in improving the miscibility. The proposed micelle model has been empolyed to interpret the testing results, such as toughness, impact strength, dynamic mechanical property and SEM morphologies. This proposed micelle model seems a worth-while method to explain the properties of partialtly miscible blends of PC and SBS.     

Preparation and characterization of 4-vinyl pyridine-grafted SBS triblock copolymer

Study on the graft of 4-vinyl pyridine to styrene-butadiene-styrene triblock copolymer by solution polymerization shows that the catalyst concentration, temperature, and reaction time are the major influencing factors. Graft efficiency increases with temperature and time but levels off when temperature is higher than 65°C. Increasing concentration of catalyst also promotes graft, but when it is higher than 1.0 × 10^?2 M, the reaction system begins to gel. A cast film of the graft copolymer was dried, cross-linked with S₂Cl₂ in nitromethane solution, sulfonated, and chloromethylated. The water content of the membrane is 13.5%. Its anionic and cationic exchange capacities are 0.066 mEq per dry gram and 0.273 mEq per dry gram, respectively. The anionic-cationic capacity ratio is thus 0.26. The nitrogen content of the graft copolymers was determined with a CHN elemental analyzer, and qualitative analysis was carried out with infrared spectroscopy. Transmitting electronic microscopy was used to study the morphology and feasibility of preparing a charged mosaic membrane for piezodialysis.     

胶粉稳定苯乙烯-丁二烯-苯乙烯三嵌段共聚物改性沥青的结构与性能

将苯乙烯-丁二烯-苯乙烯三嵌段共聚物（SBS）、废旧轮胎胶粉（GTR）和相容剂环氧天然橡胶（ENR）熔融共混,然后再分散到沥青中制备了SBS/GTR复合改性沥青,考察了ENR含量、SBS/GTR（质量比）对复合改性沥青热储存稳定性和基本性能的影响。结果表明,随着ENR含量的增加或SBS含量的减少,SBS/GTR复合改性沥青的热储存稳定性提高,当ENR质量分数为1.0%、SBS/GTR为50/50时,复合改性沥青的热储存稳定性最佳;随着ENR含量的增加,SBS/GTR复合改性沥青的软化点、针入度、延度和黏度变化不大,但当ENR质量分数为10.0%时,改性沥青的软化点明显升高,针入度下降,属于一种比较硬质的改性沥青,具有较好的施工和易性;随着SBS含量的减少,SBS/GTR复合改性沥青的软化点、黏度和延度均降低。     

Functionalization of styrene-butadiene-styrene (SBS) triblock copolymer with maleic anhydride

Summary The thermoplastic elastomers have been widely used in polymer blends to improve their mechanical properties. This work is about the study of chemical modification of styrene-butadiene-styrene (SBS) with maleic anhydride (MA) by radical reaction. The functionalization reaction was carried out in a mixer Haake Rheomix 600 and the torque variation was monitored during the process. The products were characterized by Infrared Spectroscopy (FTIR) and crosslinking was evaluated by extraction. A calibration curve was plotted to determine the functionality. The results showed that it is possible to accomplish the functionalization reaction avoiding the crosslinking. Received: 26 February 2001/Revised version: 25 June 2001/Accepted: 25 June 2001     

The mechanical properties of styrene-butadiene-styrene (SBS) triblock copolymer blends with polystyrene (PS) and styrene-butadiene copolymer (SBR)

Measurements were made of linear viscoelastic properties and nonlinear stress-strain properties of phase-separated styrene-butadiene-styrene (SBS) copolymers and their blends with several homopolymer polystyrenes (PS) and one random copolymer (SBR). Torsion pendulum testing yielded shear moduli G′, G″, and Rheovibron experiments produced tensile moduli E′, E″, over a 220°K range of temperature, both at low frequencies. For pure copolymers and their PS blends, G′ and E′ correlated quite well with the total PS content, but G″ and E″ were more sensitive to how the additive was distributed. Results suggest that a PS additive whose molecular weight (M) is less than that of the copolymer PS-block (M_s) causes expansion of both the interphase and the homogeneous PS-rich phase, while an additive with M > M_s mixes less well with these phases (probably forming separate domains of pure PS) and is less effective in enhancing the linear moduli. The blending with SBB produced reduction in G′ but a broad midrange peak in G″, suggesting that SBR was localized almost entirely within an expanded interphase. Tensile stress-strain data were obtained with an Material Testing System at room temperature. For PS blends, properties did not correlate well with the total PS content, the blends being always weaker than the SBS of the same overall composition. The amount of set also increased with PS content in the blends. Cyclic tests to increasing strain showed progressive structural alterations (as for the host SBS), with blend behavior resembling host properties more closely with each new cycle. When SBR was the additive, amounts as small as 1 percent reduced the curves by 15 percent. The yield stress was eliminated entirely with an addition of 10 percent SBR, but for all cases the set was the same. Results are discussed in terms of interphase force barriers to chain flow.     

Diamino telechelic polybutadienes for solventless styrene-butadiene-styrene (SBS) triblock copolymer formation

High molecular weight, high functionality diamino telechelic polybutadienes (TPBs) were synthesized by ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene (COD) in the presence of a chain transfer agent, 1,8-dicyano-4-octene, followed by lithium aluminum hydride reduction. Melt coupling of diamino TPB with anhydride-terminated polystyrene (PS-anh) resulted in the formation of styrene-butadiene-styrene (SBS) triblock copolymers; ca. 80% maximum conversion of PS-anh was achieved within 30 s. The results from SAXS, TEM, and rheological measurements of the coupling products confirmed the formation of SBS triblock copolymers having lamellar morphology. A fluorescent-labeled PS-anh was used to study the coupling kinetics by diluting the reactants by the addition of non-functional PS.     

二嵌段SB对SBS性能的影响

用GPC测定了苯乙烯类热塑性弹性体（SBS）合成过程中生成的二嵌段SB质量分数，讨论了其对SBS力学性能和加工性能的影响。结果表明，SB质量分数分别为21％和12％时，相应的线型和星形SBS的拉伸强度和300％定伸应力下降较大。随着SB质量分数的增加，线型SBS的扯断伸长率和永久变形增加，而星形SBS的变化不明显。适量的SB有利于加工，原因是二嵌段SB和SB进行相分离时，SB的两段进入SBS相应的微区，质量分数较小时不破坏网络结构，但却增大高温流动性。     

Study on poly(2,6-dimethyl-1,4-phenylene oxide)/SBS triblock copolymer blends

The relationship between the miscibility and the physical properties of polymer blends of poly(2,6-dimethyl-1,4-phenylene oxide) and polystyrene (PS), high-impact polystyrene (IPS) and poly(styrene-block-butadiene-block-styrene) (SBS), which are blended in different compositions by a twin-screw extruder is discussed. The three types of SBS that were used are SBS1, SBS2 and SBS3 having different styrene/butadiene ratios. Dynamic mechanical analysis and differential scanning calorimetry were used to study the miscibility. The morphology was examined by SEM. The miscibility of the blends decreases with decreasing PS content. The notch sensitivity is improved by blending. Finally, the micelle model was used to explain the testing phenomena.     

SBS改性沥青的结构与性能

通过动态黏弹性能、结构分析和沥青基本性能测试研究了SBS和沥青之间的相容性,以及SBS用量对改性沥青的结构与性能的影响。结果表明,SBS与沥青有一定的相容性,沥青中的某些组分可进入SBS的聚丁二烯(PB)链段区域。使PB的玻璃化转变温度升高,在高剪切力作用下也可进入聚苯乙烯(PS)链段,降低了PS的玻璃化转变温度,但不会使PS物理交联点发生严重解体。当SBS质量分数为5％时,SBS在沥青中呈彼此分离的球状颗粒;当SBS质量分数达到7％或以上时,则形成连续相。随着SBS质量分数的增加。改性沥青的软化点和低温延度升高,针入度和高温贮存稳定性下降。     

Formation of a polyetheramide triblock copolymer by reactive extrusion; process and properties

The synthesis of polyetheramide, containing poly(tetramethylene ether) (PTMEG) as the soft segment phase and polylactams as the hard phase was carried out in a Leistritz modular intermeshing counter‐rotating twin‐screw extruder in a one‐step, solvent‐free process. No by‐product such as carbon dioxide or H²O is formed during the reaction procedure. Isocyanate‐terminated telechelic PTMEG was premixed with caprolactam, and these were fed into the twin‐screw extruder to form the polyetheramide triblock copolymer. This triblock copolymer has not been previously polymerized in a twin‐screw extruder or continuous mixer. Subsequent to polymerization, the copolymer and PA6 homopolymer were also melt‐spun into fibers. Molecular weights and molecular weight distributions were determined by GPC on trifluroacetylated samples. Thermal, rheological, mechanical, and structural properties were investigated. It appears that phase separation (arising from immiscibility between the polyether segment and the polyamide segment as the reaction proceeds) did not hinder the chemical reaction between the two reactants because of the intense mixing in the twin‐screw extruder. The new triblock copolymer should have application as a rubber‐toughened thermoplastic or thermoplastic elastomer depending upon the elastomer content.     

The influence of molecular weight on the large deformation behavior of SBS triblock copolymer elastomers

Engineering stress–strain properties were determined for two polystyrene–polybutadiene–polystyrene (SBS) triblock copolymer elastomers, one consisting of blocks of molecular weight 7000/43000/7000 and the other, 16000/85000/17000. In addition, various blends of these two materials were prepared in order to vary the number-average molecular weight of the blocks in a systematic way while maintaining polystyrene content in the range of 25–28 wt %. Samples were solvent cast from benzene or benzene/heptane mixtures and annealed before testing. Ring specimens were extended to rupture at varying strain rates on an Instron tensile tester. Results indicate that number-average molecular weight has a marked influence on stress–strain behavior over the range of molecular weights and testing conditions employed. The observed behavior is consistent with a systematic increase in the proportion of a mixed interfacial region between the pure polystyrene and polybutadiene domain as molecular weight decreases. The interfacial region contributes to mechanical hystersis, rate sensitivity, and toughness in the SBS materials. Scanning electron photomicrographs of fracture surfaces also showed systematic changes with molecular weight.     

丙烯腈接枝SBS共聚胶粘剂的研究

以丙烯腈单体在溶剂中对ＳＢＳ进行接枝共聚,并添加增粘树脂等助剂,研制成的接枝改性ＳＢＳ胶粘剂,具有较高的粘结强度,同时还探讨了单体的含量、引发剂的用量、反应温度和时间以及增粘树脂的用量对胶液性能的影响。     

Linear dynamic mechanical properties of an SBS block copolymer

Dynamic viscosity and elastic modulus for a low molecular weight styrene-butadiene-styrene (SBS) block copolymer ate measured as a function of temperature (80-170°C) and frequency using the eccentric rotating disc geometry. These linear properties are superimposed to yield master curves each of which exhibits two branches below different (critical) reduced frequencies. At lower temperatures, the non-Newtonian behavior characteristic of SBS block copolymers is observed. In contrast, Newtonian response occurs at higher temperatures. As a consequence, plots of the viscoelastic properties vs temperature exhibit discontinuities below the critical frequencies, reflecting a narrow transition at about 142°C. Above this temperature, it is inferred, consistent with the equality of dynamic and steady state viscosities, that the polystyrene (S) blocks, existent in dispersed domains at low temperatures, exceed a critical degree of compatibility with the continuous polybutadiene phase. The activation energies indicate that the S blocks affect the temperature dependence of the dynamic properties in proportion to their presence in an interphase which is assumed to continuously grow in size as temperature is raised to the transition temperature. Below the critical reduced frequencies, it is inferred that S domain disruption may increasingly occur in conjunction with the observed property enhancement due to these domains, relative to the miscible blocks, as reduced frequency is lowered. However, above these frequencies, the presence of frequency-temperature superposition implies that the S domains and the miscible blocks are equivalent in their effects on properties. At still higher reduced frequencies, the domains present at the low temperatures studied are assumed to remain intact, but plateau behavior similar to the response characteristic of homopolymers is observed.     

苯乙烯-乙烯/丁烯-苯乙烯三嵌段共聚物用填充油的制备及性能

采用增塑剂N 4006与不同黏度的石蜡基基础油进行调配,并加入不同种类及用量的光、热稳定剂,制备了2种苯乙烯-乙烯/丁烯-苯乙烯三嵌段共聚物(SEBS)用填充油(填充油A和填充油B),并对其光安定性及热安定性进行了研究。结果表明,紫外吸收剂G-1与酚胺类复合热稳定剂R-2有显著协同作用,可有效改善油品的光、热安定性。SEBS填充油B在加入光稳定剂G-1和热稳定剂R-2后,可达到较高的光、热安定性,光热稳定剂的最佳质量分数均为0.03%。     

Sensor properties of SBS block copolymer and carbon composite film structures

Abstract

Carbon composite thin films were prepared from a styrene butadiene styrene (SBS) block copolymer matrix with dispersed graphitic carbon as the second phase. Precursor solutions in the viscosity range of 150–200 cps were developed from codispersion of SBS–carbon in toluene as solvent base. Film coatings were prepared by spin coat onto glass, alumina or silicon substrates at 2000 rev min^?1 followed by drying and vacuum heat treatment at ～80°C. Characterisation of the films was carried out using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and SEM techniques. Degree of crystallinity in the composite film structures was correlated with the strong positive temperature coefficient (PTC) effect. These composite thin films also showed high resistance sensitivity to temperature in the range from 2 90 to ?90 to +90°C. A unique feature of the resistance/temperature response was the observed negative temperature coefficient (NTC) behaviour below ～0°C combined with a strong PTC response above ～0°C. When exposed to various organic vapours, the composite films showed high selectivity, indicated by sensitive change in resistivity values.     

SBS和MMA—丙烯酸丁酯接枝聚合物的溶解性和溶度参数的订定

研究了接枝最为２１．９２％的接枝聚合物ＳＢＳ－ｇ－Ｐ（ＭＭＡ－ＢＡ）在４１种溶剂中的溶解性,表明该聚合物能完全溶解在氯仿、四氯化碳、苯、甲苯、乙酸乙酯、二氧化己环等溶剂中。用浊度滴定法测定该接枝聚合物的溶度参数为９．０３（ｃａｌ／ｃｍ＾３）＾１／２,用特性粘数法测定的溶度参数为９．００（ｃａｌ／ｃｍ＾３）＾１／２。     

Viscoelastic properties of a styrene-isoprene-styrene triblock copolymer and its blends with polyisoprene homopolymer and styrene-isoprene diblock copolymer

The effects of added polyisoprene homopolymer (PI) and polyisoprene-blockstyrene diblock copolymer (SI) on the viscoelastic properties of a polystyrene-block-polyisoprene-block-polystyrene triblock copolymer (SIS) having a spherical domain morphology have been examined. The former two species are used to model the effects of imperfections in structures that result from triblock copolymers missing, respectively, two or one polystyrene end blocks. The results indicate that the loss modulus and tangent delta in the plateau region can be dominated by imperfections in the copolymer structure. The interpretation of viscoelastic data in the rubbery plateau region as an indication of interface structure in block copolymers is therefore greatly complicated. Small angle X-ray scattering (SAXS) and rheological tests were also used to determine the order-disorder transition temperature for an SIS triblock copolymer and its blend with an SI diblock. The SAXS data are consistent with Han's rheological criteria for determining the order-disorder transition temperature. However, the complex viscosity does exhibit Newtonian behavior for low rates at the highest temperatures, even though the domain morphology persists. Stress relaxation and dynamic modulus data at high temperatures clearly show a secondary “rubbery” plateau at long times, and we offer a qualitative explanation for this feature based on a proposed relaxation mechanism.