聚1-丁烯热塑性弹性体的基础加工性能

通过测试力学性能及采用差示扫描量热、红外光谱等手段分析了加工条件对聚1-丁烯热塑性弹性体力学性能、结晶行为和结构的影响。结果表明,聚1-丁烯热塑性弹性体的力学性能与试样成型后的停放时间有关,试样需在室温下放置不少于10 d其力学性能才能达到稳定状态,才可进行力学性能的测试;适宜的模压温度为140～160℃;重复加工4次以上聚1-丁烯的力学性能基本不变,说明其是一种可以再利用的热塑性弹性体;采用模压成型方式更容易获得性能稳定的聚1-丁烯热塑性弹性体制品。     

聚1-丁烯热塑性弹性体的应用及制备方法

综述了聚1-丁烯热塑性弹性体的主要应用领域,包括防水卷材、电气绝缘材料、耐酸碱胶板和普通工业胶板、聚丙烯增韧改性;介绍了聚1-丁烯热塑性弹性体的3种制备方法,即溶液聚合法、本体聚合法和反应挤出法,并分析了各种方法的优缺点。     

聚1-丁烯热塑性弹性体的老化与防护

以拉伸性能为主要检测指标，考察了聚1-丁烯[P(1-Bt)]热塑性弹性体的热氧老化、紫外光老化和耐酸碱老化性能，制备了P(1-Bt)和三元乙丙胶(EPDM)防水卷材试样并进行对比：结果表明：单独使用抗氧剂1010，其用量在0．1～0．2质量份时具有较好的防热氧效果；1010与DLTP配合使用效果更佳，最佳配比为m(1010)：n(DLTP)=1：3(1010为0．2份)。热氧防老剂与紫外光吸收剂并用明显优于热氧防老剂或紫外光吸收剂单用时的防紫外光效果；ZnO对热氧老化和紫外光老化也具有很好的防护作用。P(1-Bt)制备的防水卷材的耐紫外光老化性能接近EPDM防水卷材，耐酸碱性能优于后者。     

负载钛体系催化合成聚1-丁烯热塑性弹性体

研究了采用TiCl4/MgCl2 Al(i Bu)3负载钛催化体系合成聚1 丁烯(PBt)热塑性弹性体的规律。结果表明:最佳聚合条件是:Bt质量分数25%,n(Ti)∶n(Bt)=1×10-5∶1,n(Al)∶n(Ti)=(200～300)∶1,温度30℃。与聚合瓶小试条件相比,由于有良好的搅拌增加了传热传质效果,因此可获得更高的聚合速率和产率,且所合成的PBt的Mw和不溶物含量均较相同聚合条件下聚合瓶中的有所降低;氢气可有效调节PBt相对分子质量。     

不同聚合方法合成聚1-丁烯热塑性弹性体的结构与性能

比较了分别通过溶液聚合和本体聚合所得聚1-丁烯热塑性弹性体的物理机械性能.结果表明,用溶液法制得的聚1-丁烯的物理机械性能要优于本体法,也更接近于热塑性弹性体.核磁共振和差示扫描量热分析表明,在相同的聚合条件下,用溶液法所得聚1-丁烯分子链的规整度要高于本体法聚合产物,其结晶程度也更高.     

聚合条件对合成聚1-丁烯热塑性弹性体的影响

以1-丁烯(B t)为原料,负载钛(简称Ti)-三异丁基铝(简称Al)为催化体系,用本体聚合法合成了聚1-丁烯(PBt)热塑性弹性体(TPE)。考察了聚合条件对PBt TPE的影响,并用差示扫描量热法对聚合物进行了分析。结果表明,随着氢气压力的升高,单体转化率、催化效率呈下降趋势;随着Al/Ti(摩尔比)的增加,转化率和催化效率先升高后降低;随着Ti/Bt(摩尔比)的增加,转化率和催化效率逐渐升高;随着聚合温度的升高,转化率和催化效率先升高后降低;在氢气压力为0.2 MPa、Al/Ti为300、Ti/Bt为2×10-5、反应温度为30℃的聚合条件下,合成出转化率为80.0%的PBt TPE。随着氢气压力的升高,聚合物的特性黏数([η])和全同立构质量分数都呈下降趋势,氢气压力能较好地调节聚合物的相对分子质量;随着Al/Ti的增加,[η]逐渐下降,全同立构质量分数变化不明显;随着Ti/Bt的增加,[η]先升高后降低,最后趋于平稳,而全同立构质量分数略有降低后趋于平稳;随着聚合温度的升高,[η]和全同立构质量分数都呈下降趋势。反应温度为40℃时,PBt TPE的结晶度最高,为20.3%。     

聚1-丁烯的制备

采用自制的TiCl4/MgCl2-Al(i-Bu)3负载钛催化体系,合成了聚1-丁烯热塑性弹性体,考察了聚合温度对单体转化率、聚合物结构及其性能的影响。结果表明:当聚合温度为30℃时,单体转化率最高,达83％;聚合物的玻璃化转变温度最高,为-16．2℃;聚合物的回弹率最大,为25．9％;聚合物的拉伸强度最大,为15．7 MPa。     

聚1-丁烯弹性体及1-丁烯与1-己烯共聚弹性体的流变性能

采用恒速双筒毛细管流变仪研究了自制的聚1-丁烯热塑性弹性体(PB-TPE)及1-丁烯与1-己烯共聚弹性体(B-co-H)的流变性能.结果表明,相同条件下PB-TPE和B-co-H均为假塑性流体,B-co-H的非牛顿性更强,PB-TPE比B-co-H的黏流活化能高.随着1-己烯含量的增大,共聚物分子链柔顺性增加,加工性能...     

反应挤出法聚1-丁烯热塑性弹性体的合成及表征

采用负载钛催化体系[TiCl4/MgCl2-Al(i-Bu)3],在反应挤出机上合成了聚1-丁烯热塑性弹性体(PB-TPE),与聚合釜本体聚合法合成的PB-TPE的力学性能、热性能、元素组成以及催化剂的催化效率进行了比较。结果表明,利用反应挤出法合成PB-TPE是可行的;与聚合釜本体聚合法合成的PB-TPE相比,其力学性能还不理想,在热性能和元素组成上也有一定差异,且催化剂的催化效率较低。     

单茂钛催化1-丁烯合成聚1-丁烯

以单茂钛化合物／ＭＡＯ为催化剂催化１－丁烯聚合。产物以＾１３Ｃ－ＮＭＲ,ＧＰＣ,ＤＳＣ,ＤＭＡ表征,结果表明该聚合物是一种立体嵌段的高相对分子质量的热塑性弹性体。     

硬段对热塑性聚氨酯弹性体结构及性能的影响

以实验室自制聚己二酸乙二醇酯二醇PEA为软段,二苯基甲烷-4,4’二异氰酸酯(MDI)为硬段,分别采用乙二醇(EG、1,4-丁二醇)、BOD和1,6-己二醇、HG为扩链剂,经预聚体法合成了硬段不同的聚氨酯弹性体。研究了硬段结构和硬段含量对弹性体硬度及力学性能的影响。采用旋转流变仪研究了弹性体在降温条件下的非等温结晶过程。结果表明,当硬段含量相同时,BDO-TPU结晶性能最好,拉伸强度最大;HG-TPU断裂伸长率最好。在BDO-TPU体系中,随硬段含量增加,材料硬度和强度增加,伸长率减小;结晶起始温度逐渐增大,结晶性能增强。     

Effect of structure development on the rheological properties of PVDF/HNBR-based thermoplastic elastomer and its vulcanizates

The present work demonstrates the structure-rheology relationship of novel polyvinylidene fluoride/hydrogenated nitrile rubber blends with special reference to the effect of mixing time, which has not been amply discussed in the literature. In between 50 and 70 wt% rubber content, a yield in complex viscosity and secondary plateau in storage modulus were discerned due to interconnected droplets-matrix morphology manifesting the thermoplastic elastomeric nature of the blends (TPEs). Such network-like structure altered the rheological properties like relaxation time, capillary viscosity, die swell, elastic responses of the TPE with respect to the trend as expected according to the rule of mixing. Interestingly, in the early stages of mixing, when the dispersed size was bigger, the effect of physical network on the rheological properties was suppressed. During dynamic vulcanization (TPV), both lower and higher frequency responses in oscillatory shear flow, steady shear rheological properties, recoverable strain etc. have changed notably with mixing time. For example, although the complex viscosity of the TPV was higher at a lower frequency as compared to its TPE, it was significantly lower at a higher frequency at the beginning of dynamic curing; however, viscosity increased appreciably with time. Temperature-dependendent rheological properties were also influenced with mixing time of the compositions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48758.     

Effect of the processing molding temperature on the crystalline structure and properties of acrylonitrile‐butadiene rubber/trinylon thermoplastic vulcanizates

The effect of the processing molding temperature on the properties and crystalline structure of acrylonitile‐butadiene rubber (NBR)/nylon 6,66,1010 (trinylon) thermoplastic vulcanizates (TPV) was studied. With decreasing molding temperature, the stress at 100% and elongation at break of TPV changed slightly, and the solvent resistance of TPV improved. The best conditions for processing molding were 170°C and 12 min. The crystalline structure of the nylon continuous phase in TPV was investigated by X‐ray diffraction, polarized optical microscopy, and differential scanning calorimetry. The results show that the crystalline structure of the nylon phase in TPV was more perfect/orderly and formed α‐crystalline structure at a processing molding temperature of 170°C. Therefore, the oil resistance of NBR/trinylon TPV clearly improved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1374–1379, 2006     

Effect of clay on properties of ionic thermoplastic elastomer based on EPDM

Incorporation of hard clay causes improvement in most of the physical properties of zinc-sulfonated EPDM of high ethylene content. Zinc stearate reduces the melt viscosity of the clay-filled zinc-sulfonated EPDM during high-temperature processing, but does not adversely affect the physical properties at ambient temperatures. Studies include the measurement of physical properties, scanning electron microscopy (SEM), processability studies in a Monsanto processability tester (MPT), and dynamic mechanical analyses (DMA). © 1996 John Wiley & Sons, Inc.     

Low temperature impact properties of long fiber thermoplastic composite molding materials

Four long fiber thermoplastic resin matrices, nylon 6, polypropylene, polyethylene terephthalate, and styrene maleic anhydride, containing differing amounts of long fiber glass reinforcement, were tested for notched Izod impact strength over the temperature range of 22 to −32°C. The notched impact properties of the long fiber thermoplastic composite molding materials are substantially greater than literature values for short fiber analogues. The fiber dominant performance of the long fiber materials is evidenced by increasing impact values with corresponding increases in weight percent fiber content. No apparent ductile/brittle transition in the fracture mode was observed for the long fiber materials that were tested.     

聚烯烃弹性体/聚丙烯热塑性弹性体的制备及力学性能

以过氧化物为硫化剂,用动态硫化法制备了聚烯烃弹性体(POE)/聚丙烯(PP)热塑性弹性体,研究了硫化剂用量、填料种类和加工次数对体系力学性能的影响。结果表明,增加硫化剂用量可以提高体系的拉伸强度,降低拉伸永久变形和压缩永久变形。碳酸钙和滑石粉对POE/PP体系无明显增强作用,炭黑的增强作用较此二者明显一些,这三种填料加入后都会使体系的扯断伸长率降低而硬度增大。加入石蜡油会使体系的扯断伸长率和压缩永久变形增大、硬度和拉伸强度降低。加工次数对POE/PP体系的力学性能无明显影响,说明体系具有较好的重复加工性能。     

塑化温度和成型温度对增塑PVC及PVC／PNBR弹性体力学性能的影响

当塑化温度分别为135℃和150℃时,通过测定不同成型温度下（145、150、155、160℃）压片制得的增塑PVC和PVC／PNBR共混物的断裂伸长率、拉伸强度、硬度和拉伸永久变形,研究了塑化温度和成型温度对试样力学性能的影响。结果表明：①150℃塑化温度下,物料塑化得更完全,PVC分子链间的作用力增强,试样的拉伸强度、拉伸永久变形、硬度增大;②在成型温度为145-155℃范围内,试样的断裂伸长率、拉伸强度随成型温度的提高都显著增大;③与塑化温度相比,成型温度对试样力学性能的影响更大。