TPI用量对TPI/NR并用胶微观结构的影响

研究反式1,4-聚异戊二烯(TPI)用量对TPI/NR并用胶微观结构的影响.试验结果表明,随着TPI用量的增大,TPI/NR并用胶中TPI球晶区域增大,当TPI用量为20份时结晶区由分散变为连续;TPI用量对TPI/NR混炼胶中TPI结晶度影响不大,TPI结晶破坏的主要因素是硫化;随着TPI用量增大,TPI/NR硫化胶中TPI微晶增多.     

交联对反式聚异戊二烯结晶及结晶速率的影响

测定了不同硫黄用量的反式－1,4－聚异戊二烯（TPI）硫化胶的溶胀比,平均交联点间的相对分了质量,室温下力学笥能发生突变时的临界平均交联点间的相对分子质量和临界结晶度,并研究了交联对TPI结晶的影响,测出了不同交联度TPI硫化胶的硬化的曲线和结晶曲线,结果表明,硫化明显阻碍了TPI的结晶,使TPI的结晶速率和硬化速率变慢,炭黑的另入相当于提高了硫用量,不利于TPI的结晶。     

拉伸疲劳过程中未填充丁苯橡胶/反式-1,4-聚异戊二烯共混硫化胶性能的变化

研究了反式-1,4-聚异戊二烯(TPI)用量不同的未填充丁苯橡胶(SBR)/TPI共混硫化胶的拉伸疲劳性能,考察了TPI用量为20份(质量,下同)的未填充SBR/TPI共混硫化胶在拉伸疲劳过程中动态性能及TPI结晶性能的变化。结果表明,TPI用量为20份或30份时SBR/TPI共混硫化胶的拉伸疲劳性能较好,随TPI用量增加其疲劳断裂表面的撕裂线逐渐增多。X射线衍射分析表明SBR/TPI(质量比为80/20)共混硫化胶的结晶衍射峰强度随着拉伸疲劳次数的增加而不断增强。动态力学分析表明SBR与TPI的相容性良好;随拉伸疲劳次数增加SBR硫化胶损耗因子的峰值不断降低,而TPI用量为20份的SBR/TPI共混硫化胶在拉伸疲劳过程中损耗因子峰值的变化不明显,但损耗因子在40～60℃有较大幅度的下降。     

反式-1,4-聚异戊二烯的结晶性对丁苯橡胶/反式-1,4-聚异戊二烯共混硫化胶拉伸性能的影响

用X射线衍射仪分析了反式-1,4-聚异戊二烯(TPI)的拉伸结晶性能,研究了其对丁苯橡胶(SBR)/TPI共混硫化胶拉伸性能的影响。结果表明,TPI具有明显的拉伸诱导结晶特性。未填充炭黑的SBR/TPI共混硫化胶及TPI硫化胶的结晶衍射峰强度从大到小依次为预拉伸试样、拉断试样和原始试样,并且TPI用量越多相应试样的结晶衍射峰强度越大;炭黑填充SBR/TPI共混硫化胶的结晶度比相应的未填充试样低得多。炭黑填充SBR/TPI共混硫化胶的拉伸强度比未填充胶料明显提高,硬度随TPI用量增加而提高的幅度低于未填充者;未填充胶料的扯断伸长率先降低后升高,而填充胶料整体上呈现下降的趋势;未填充及填充胶料的100%定伸应力都随着TPI用量的增加而升高;炭黑填充胶料在50 mm/min拉伸速率下的拉伸强度比500 mm/min拉伸速率下测得结果的增长幅度以及预拉伸试样比原始试样拉伸强度的增长幅度都小于未填充胶料。     

纳米导电纤维填充硅橡胶的性能

在乙烯基甲基硅橡胶（ＶＭＱ－１１０）中加入自制的纳米乙炔导电纤维（Ｎａｎｏ），可制备出性能良好的导电橡胶，实验表明，在ＶＭＱ－１１０中加入１０～３５份Ｎａｎｏ其混炼胶的导电性能接近导电乙炔炭黑混炼胶，且混炼胶柔软，加工性好，当Ｎａｎｏ用量大于３０份时，硫化胶的ρｓ小于１０＾３Ω，加入５０份ρＶ降至１０Ω．ｃｍ；随着Ｎａｎｏ用量增加，硫化胶的硬度，拉伸强度都增加，扯断伸长率呈线性下降。     

硫黄用量对反式1，4-聚异戊二烯结晶及硫化胶性能的影响

研究了硫黄用量对反应１,４－聚异戊二烯（ＴＰＩ）由塑性高聚物转变为弹性高聚物后性能的影响。结果表明,硫黄用量５份是ＴＰＩ硫化胶物理性能和动态力学性能随硫黄用量变化的转折点,并且此时ＴＰＩ硫化胶具有较好的综合性能,其内部的结晶破坏程度可达８８．９％,在实用配方中,由于其它胶种和填料的加入,使ＴＰＩ的结晶度可下降约９９％,为ＴＰＩ在轮胎中应用提供了理论依据。     

低相对分子质量反式-1,4-聚异戊二烯蜡在NR/TPI并用胶中的应用

将低相对分子质量反式-1，4-聚异戊二烯蜡（LMTPIW）代替芳烃油用于天然橡胶（NR）和反式-1，4-聚异戊二烯（TPI）并用胶中．研究其对并用胶性能的影响。结果表明，用LMTPIW代替芳烃油用于NR／TPI并用胶中，操作方便，可改善混炼胶的加工性能，混炼胶的焦烧时间延长；提高了硫化胶的拉断伸长率、撕裂强度、屈挠性能；改善了炭黑的分散性；热空气老化性能略有下降。LMTPIW用量在10～15份时，与加入5份芳烃油后的增塑效果相当．屈挠性能可提高2～4倍，胶料的综合性能最佳。     

促进剂对氯丁胶/反式-1,4-聚异戊二烯并用胶性能的影响

将促进剂TMTD、NA-22和DM用于氯丁橡胶（CR）和反式-1，4-聚异戍二烯（TPI）并用胶中，研究其对并用胶性能的影响。结果表明，与促进剂NA-22和DM相比，促进剂TMTD可以降低混炼胶的门尼粘度，提高胶料的流动性；缩短正硫化时间，有利于改善加工工艺，提高硫化效率。加入促进剂DM的胶料焦烧时间比较长，加工安全性提高，但正硫化时间过长，硫化效率低。加入促进剂TMTD的胶料拉伸强度、拉断伸长率、撕裂强度等物理机械性能优异，屈挠性能提高显著；耐老化性能略有下降。当促进剂TMTD的用量在1．0～1．3份时胶料的综合性能最好。     

反式-1，4-聚异戊二烯及其混炼胶的流变特性

采用孟山都加工性能试验仪研究了反式－1，4－聚异戊二烯（TPI）及其混炼胶的演变特性。结果表明，TPI表观粘度ηa高于NR，SBR和BR，并随着剪切速率的增大或温度的升高而减小；TPI的粘流活化能ΔEη与NR相近，比BR和SBR高；在TPI与NR，SBR和BR并用胶料中加入加工助剂可使加工性能得以改善。     

热膨胀物理微球发泡剂在形状记忆材料中的应用研究

研究了热膨胀物理微球发泡剂Expancel920DU40在反式聚异戊二烯(TPI)形状记忆材料中的应用,考察了发泡剂用量对TPI混炼胶硫化特性、力学性能和形状记忆性能的影响。结果表明,加入热膨胀物理微球发泡剂会破坏材料结晶,材料力学性能下降;由于可逆相结晶区被破坏,材料形状回复率Rr降低;发泡剂用量为1份时,材料力学性能和形状记忆性能均最优。     

The strength of particulate polymer composite: A new insight on crystallinity and structural morphology

We have demonstrated the significant impact of high density polyethylene (HDPE) crystallinity and structural morphology on the tensile strength of 60/40 NR/HDPE polymer blend composites. Introducing nanoscale Boron Carbide (B4C-type compounds) fillers noticeably changed the crystallinity and morphology of HDPE, leading to the formation of fine spherulites. Conversely, microscale fillers mainly impacted the crystallinity while preserving a coarse architecture. Although both composites experienced a reduction in crystallinity, the nanocomposites outperformed microcomposites and even the pristine polymer blend in terms of strength, implying the effect of a fine structure. The nanocomposite with a filler loading of 2 wt% exhibited the highest strength. This investigation provides novel insights into the interplay between crystallinity, HDPE structure, and the size of fillers, which heavily influence the strength of polymer blend composites.     

Effect of single‐mineral filler and hybrid‐mineral filler additives on the properties of polypropylene composites

The present study was carried out to determine the filler characteristics and to investigate the effects of three types of mineral fillers (CaCO₃, silica, and mica) and filler loadings (10–40 wt%) on the properties of polypropylene (PP) composites. The characteristics of the particulate fillers, such as mean particle size, particle size distribution, aspect ratio, shape, and degree of crystallinity were identified. In terms of mechanical properties, for all of the filled PP composites, Young's modulus increased, whereas tensile strength and strain at break decreased as the filler loading increased. However, 10 wt% of mica in a PP composite showed a tensile strength comparable with that of unfilled PP. Greater tensile strength of mica/PP composites compared to that of the other composites was observed because of lower percentages of voids and a higher aspect ratio of the filler. Mica/PP also exhibited a lower coefficient of thermal expansion (CTE) compared to that of the other composites. This difference was due to a lower degree of crystallinity of the filler and the CTE value of the mica filler. Scanning electron microscopy was used to examine the structure of fracture surfaces, and there was a gradual change in tensile fracture behavior from ductile to brittle as the filler loading increased. The nucleating ability of the fillers was studied with differential scanning calorimetry, and a drop in crystallinity of the composites was observed with the addition of mineral filler. Studies on the hybridization effect of different (silica and mica) filler ratios on the properties of PP hybrid composites showed that the addition of mica to silica‐PP composites enhanced their tensile strength and modulus. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

TPI结晶性对SBR/TPI并用胶物理机械性能的影响

研究了TPI结晶性对有效硫黄硫化体系（EV）硫化的SBR/TPI并用胶硫化特性和物理机械性能的影响。结果表明,随着TPI用量的增加,SBR/TPI并用胶的交联密度提高,t10和t90先增大后减小;在TPI用量为20份时,t10和t90均达到最大值;TPI冷冻结晶对SBR/TPI并用胶拉伸性能影响不大,拉伸诱导结晶能够提高SBR/TPI并用胶的拉伸强度和100%定伸应力,但降低了拉断伸长率;50mm/min拉伸速率下测得的拉伸强度比500mm/min下测得的数值偏高;TPI用量增大,SBR/TPI并用胶的压缩强度和压缩永久变形均增大。     

TPI结晶性对CV体系硫化SBR/TPI并用胶性能的影响

研究了反式-1,4-聚异戊二烯（TPI）结晶性对传统硫磺硫化（CV）体系硫化丁苯橡胶（SBR）/TPI并用胶硫化特性及物理性能的影响。结果表明,增大TPI的并用量,能够提高SBR/TPI并用胶的交联密度和硫化速度,延长焦烧时间;TPI冷冻结晶对SBR/TPI并用硫化胶的拉伸性能影响不大,拉伸诱导结晶能够提高SBR/TPI并用硫化胶的拉伸强度和100%定伸应力,降低SBR/TPI并用硫化胶扯断伸长率;随着TPI并用量的增大,SBR/TPI并用硫化胶的压缩强度和压缩永久变形增大。     

Injection molding of biodegradable polyester blends filled with mineral and sustainable fillers: Performance evaluation

This research focuses on the melt processing of biocomposites from a biodegradable polymer blend mixed with hybrid fillers through injection molding technique. An optimized blend ratio (60/40 wt%) poly(butylene succinate-co-butylene adipate) (PBSA) and poly(butylene adipate-co-terephthalate) (PBAT) demonstrated promising results after blending with a mixture of walnut shell powder (WSP), corn starch and talc in various proportions for use in rigid packaging. The addition of hybrid fillers (i) 10% WSP with 15% talc and (ii) 5% WSP with 5% starch and 15% talc to the polymer blend (60%PBSA/40%PBAT) improved tensile modulus (160% and 162%, respectively) and flexural modulus (147% and 153%, respectively) because of the dispersion of stiffer talc and WSP. Following the addition of fillers, tensile strength of the composites decreased. However, flexural strength improved significantly after filler introduction because of better stress transfer ability. Rheological analysis of filled composites with starch or WSP (25%) depicted similar characteristics of the polymer blend, indicating lower viscosity than hybrid composites. The abundant hydroxyl groups in starch explained the increased water absorption and decreased contact angle compared with other composites. This research's novelty encompasses utilizing low-cost biomasses with mineral filler into an under-researched biodegradable polymer blend suitable for single-use rigid packaging applications.     

Mechanical properties and morphologies of PP/mPE/filler composites

Because of the poor impact behavior of polypropylene (PP) at low temperatures, the blending of PP with metallocene‐polymerized polyethylene (mPE) elastomers was investigated in this study. However, a reduced modulus of the overall blend was inevitable because of the addition to elastomers. To obtain a balance of the properties, we introduced rigid inorganic fillers to PP/mPE blends. The performance of the composites was characterized with tensile and Charpy notched impact tests, and the fracture morphology was examined with scanning electron microscopy. The results showed that the effects of fillers in a brittle matrix and in a ductile matrix were quantitatively different. For PP/mPE/filler ternary composites, the dependence of Young's modulus and yield strength on CaCO₃ content was not significant compared with that of PP/filler binary composites, whereas the elongation at break and tensile toughness at room temperature for PP/mPE/filler systems were more improved. The impact strength of the PP/mPE blends filled with untreated glass beads and CaCO₃ at a low temperature was lowered because of the weak interfacial bond. However, the values of the impact strength of the PP/mPE/filler composites at a low temperature remained at a high level compared with that of pure PP. In particular, a PP/mPE blend filled with surface‐treated kaolin had a higher low‐temperature impact toughness than the unfilled blend. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3029–3035, 2002; DOI 10.1002/app.2333     

TPI结晶性对DCP硫化TPI胶料性能的影响

研究了反式-1,4-聚异戊二烯（TPI）结晶性对不同用量过氧化二异丙苯（DCP）硫化的TPI性能的影响。结果表明,拉伸前后TPI试样的XRD曲线上结晶峰有明显不同。TPI预拉伸冷冻试样的拉伸性能与冷冻前后原始试样的差异明显。随着DCP用量的增加,500mm/min和50mm/min拉伸速率下测得的拉伸强度之间的差异变得越来越小;同一压缩率时,试样的压缩强度不断降低。在tanδ-温度曲线上,随着交联密度的提高,TPI低温损耗峰的tanδ值不断增大,而其高温损耗峰的tanδ值呈下降趋势。     

MWCNT/Hectorite hybrid filled acrylonitrile butadiene rubber/ ethylene-co-vinyl acetate blend nanocomposites: preparation and properties

Multiwalled carbon nanotube/hectorite hybrid filler (HMH) was prepared by simple dry grinding method. It was subsequently used for the reinforcement of technologically compatible acrylonitrile butadiene rubber (NBR)/ ethylene-co-vinyl acetate (EVA) blend through solution intercalation method. Analysis of the prepared blend nanocomposites confirms homogeneous dispersion of the constituent fillers in the polymer matrix and significant interaction between two types of constituent fillers. Mechanical properties of NBR/EVA blend are significantly improved with HMH content up to 4 wt.% followed by reversion. Maximum improvement observed in tensile strength, elongation at break and toughness are 106%, 37% and 171% respectively without significant rise in Young’s modulus. Results also show best dynamic mechanical and dielectric response at 4 wt.% and 3 wt.% HMH content respectively. Enhanced mechanical, dynamic mechanical and dielectric properties of the blend nanocomposites attained may be attributed to fair degree of compatibility between the two polymer matrices, homogeneous dispersion of fillers and improved polymer-filler interaction.     

填料改性充油SEBS力学性能的研究

采用熔融共混方法研究了碳酸钙填充充油SEBS复合材料的力学性能的影响。力学性能测试表明:填料的种类不同对SEBS复合材料的性能有一定的影响,随着填料的用量增加,共混物的拉伸强度下降,100%拉伸永久变形、扯断永久变形和断裂伸长率都逐渐增大。     

环氧树脂/氧化锌晶须/氮化硼导热绝缘复合材料的研究

以环氧树(脂EP)为基体,分别以氧化锌晶(须ZnOw)和ZnOw/氮化硼(BN)混合物为导热填料,制备了EP导热绝缘复合材料。研究了填料含量对复合材料导热性能、电绝缘性能及力学性能的影响,并利用扫描电镜对复合材料的断面形貌进行了观察。结果表明:随着导热填料含量的增大,复合材料的导热系数和介电常数增大,体积电阻率下降,而拉伸强度呈先增大后减小的趋势;在填料含量相同的情况下,EP/ZnOw/BN复合材料比EP/ZnOw复合材料具有更好的导热性能;当填料体积分数为15%时,EP/ZnOw/BN复合材料的热导率为1.06W/(mK)而,EP/ZnOw复合材料的热导率仅为0.98W/(mK)。