快速软模浇注成型用聚氨酯树脂

利用二苯基甲烷二异氰酸酯(MDI)、液化MDI、聚醚多元醇及小分子扩链剂、交联扩链剂,分别采用半预聚物法及一步法合成了两类适用于硅胶模真空浇注成型的二组分聚氨酯(PU)树脂。分析了树脂黏度及釜中寿命。对PU试样进行了差示扫描量热分析(DSC)、热重分析(TGA)及力学性能分析。结果表明,PU树脂两组分及其混合物的黏度较小,釜内寿命适中,浇注性能优良;玻璃化温度在110℃以上,热重损失为5%时的热失重温度在260℃以上;具有较高的力学性能。     

PTMG基浇注型PU弹性体的制备与性能研究

以聚四氢呋喃醚二醇(PTMG)、4,4′-二苯基甲烷二异氰酸酯(MDI)和1,4-丁二醇(BDO)为原料,通过预聚体法制得不同异氰酸酯(—NCO)基含量预聚体,用BDO作扩链剂合成浇注型聚氨酯(PU)弹性体。考察了预聚体中—NCO基含量对PU弹性体力学性能的影响,用X射线衍射仪、维卡软化点测定仪和热失重分析仪对材料进行分析表征。结果表明:PU弹性体随预聚体—NCO基含量的增加,硬度、拉伸强度、模量和撕裂强度增大,断裂伸长率和冲击弹性下降。当预聚体—NCO基含量为8.0%时,PU弹性体的综合力学性能最佳,拉伸强度和撕裂强度分别是39.4MPa和142.7kN/m;维卡软化温度达到127.5℃,具有较好的热性能。     

扩链剂对MDI型聚氨酯结构与性能的影响

扩链剂类型对聚氨酯（PU）的结构性能有较大影响。分别采用1,4-丁二醇（BDO）、对苯二酚二羟乙基醚（HQEE）、3,3’-二氯-4,4’-二氨基二苯基甲烷（MOCA）和封端二苯基甲烷二胺（S-MDA）为扩链剂,制备了聚四氢呋喃醚二醇（PTMG）/MDI型PU弹性体。通过红外光谱、差示扫描量热法、动态力学热分析及热重分析等方法,研究了扩链剂结构对PU微相分离及性能的影响。结果表明,胺类扩链剂生成的脲基有利于硬段间形成强氢键,软硬段间微相分离程度更大,提高了硬段结晶度、力学强度和耐热性,降低了软段玻璃化转变温度和损耗因子。     

无有机溶剂法合成水性聚氨酯-聚丙烯酸酯胶粘剂

采用羧酸型亲水扩链剂二羟甲基丁酸(DMBA)以及磺酸型亲水扩链剂2,4-二氨基苯磺酸钠(SDBS),选用乙烯基单体作为聚氨酯(PU)预聚合的连续相,制备了稳定的无挥发性有机溶剂(VOC)水性聚氨酯-聚丙烯酸酯(SPUA)胶粘剂。利用傅里叶变换红外光谱(FT-IR)对改性前后PU的分子结构进行分析对比,并考察了亲水扩链剂用量、聚丙烯酸酯(PA)含量对胶粘剂的耐水性、稳定性和力学性能的影响。结果表明。当SDBS含量为2%(wt,质量含量,下同),DMBA为4.5%,PA为25%时,SPUA胶粘剂的耐水性、稳定性和力学性能最佳,固含量可达43%。透射电镜(TEM)照片表明,SPUA乳胶粒呈圆球状,乳液平均粒径分布均匀。     

含不同扩链剂的聚叠氮缩水甘油醚基含能热塑性弹性体的合成与力学性能EI北大核心CSCD

采用不同碳链长度的小分子二元醇扩链剂乙二醇、丙二醇、丁二醇、戊二醇和己二醇合成了聚叠氮缩水甘油醚(GAP)基含能热塑性弹性体(ETPUE)。通过凝胶渗透色谱、傅里叶变换红外光谱、动态热机械分析测试和力学性能测试研究了不同扩链剂扩链的ETPUE的性能变化规律。结果表明,当碳原子数大于2时,偶数碳扩链剂的ETPUE的氢键化程度较高,力学性能好;奇数碳扩链剂的ETPUE的氢键化程度较低,力学性能较差;碳原子数为2时,由于链段很短,氢键化程度较低,性能较差。己二醇扩链的ETPUE的综合性能最佳。     

含有悬挂链结构的新型聚氨酯阻尼材料的研究

在以甲苯二异氰酸酯(TDI)、六亚甲基二异氰酸酯(HDI)、聚四氢呋喃醚二醇(PTMG)、蓖麻油为原料的聚氨酯(PU)弹性体体系中加入了一种新型含有悬挂链结构的二元醇扩链剂,制得新型阻尼材料;论述了硬段及交联剂的种类和配比对PU阻尼性能的影响。结果表明:悬挂链结构二元醇扩链剂的加入,可有效提高PU弹性体在Tg之后的阻尼因子,显著改善其阻尼性能。     

高黏度聚乙烯醇缩丁醛树脂及薄膜的制备

通过添加适量的扩链剂制备了高黏度的聚乙烯醇缩丁醛(PVB)树脂及薄膜.讨论了扩链剂的加入对PVB树脂及薄膜性能的影响.实验证明,合成树脂时加入相对于正丁醛体积3%左右的扩链剂;加工成膜时,加入相对于PVB树脂质量3%以下的扩链剂,可明显提高PVB的分子量,降低PVB薄膜与玻璃的粘结性能,所得薄膜的拉伸强度可由2～3MPa提高到20MPa左右,而且制得的夹层安全玻璃的耐冲击性能没有受到影响.     

室温固化聚醚型聚氨酯弹性体的制备及研究

以可再生资源蓖麻油为起始剂环氧丙烷开环聚合的聚醚多元醇、聚丙二醇醚多元醇、TDI、MOCA等为主要原料,采用半预聚物法,室温固化制备双组分浇注型聚氨酯弹性体(CPUE).对该新型聚氨酯弹性体进行了红外光谱测试,结果表明其分子结构中含有氨基甲酸酯基、醚键等基团的特征吸收峰;通过力学性能测试,原料中聚醚多元醇的种类、NCO基质量分数的改变都会引起弹性体性能的差异,这些差异存在一定的规律性;DSC差示扫描结果表明,聚氨酯弹性体分子链中硬段含量升高,玻璃化转变温度(Tg)升高;利用热重分析(TG)研究了其耐高温性能,结果表明硬段含量和扩链剂种类都会影响PUE的热稳定性.     

一种基于有序硬段的可生物降解聚氨酯的制备及性能

以聚乙二醇(PEG,Mn=600、1000)为引发剂,L-丙交酯(L-LA)为单体,在辛酸亚锡存在下开环聚合合成了三嵌段预聚物聚丙交酯-聚乙二醇-聚丙交酯(PLA-PEG-PLA),然后以具有有序结构的二氨基甲酸酯基二异氰酸酯(六亚甲基二异氰酸酯-1,4-丁二醇-六亚甲基二异氰酸酯,HBH)扩链制备了一种可生物降解的脂肪族聚氨酯(PU-I、PU-II)。作为对比,以4,4’-二苯基甲烷二异氰酸酯(MDI)作为扩链剂合成了芳香族聚氨酯(PU-III)。通过核磁共振、红外光谱、超高分辨质谱、凝胶渗透色谱等对预聚物、扩链剂、聚氨酯的化学结构进行了表征。通过对PU-I、PU-II和PU-III膜热性能、力学性能和体外降解性能的对比,研究了有序硬段对聚氨酯性能的影响。结果表明,相对于PU-III,PU-I具有更好的力学性能(断裂强度21 MPa,断裂伸长率840%)和较快的体外降解(19d);随着亲水链段PEG含量的增加,PU膜(PUII)的断裂强度降低,断裂伸长率增加,同时体外降解速率变快。该类型的脂肪族聚氨酯具有降解产物无毒、合适的力学性能和降解性能,可替代传统的芳香族聚氨酯,在医疗行业中有更广泛的用途。     

聚氨酯弹性体隔振性能分析

采用TDI和MDI通过预聚物法进行浇注型聚氨酯弹性体的合成。分析预聚物中异氰酸酯基含量和扩链剂的种类对聚氨酯弹性体力学性能的影响。浇注型聚氨酯隔振器与橡胶隔振器相比，具有更低的固有频率、更好的动态性能和更高的承载能力。疲劳试验结果表明聚氨酯隔振器具有优良的抗疲劳性能。     

预聚法制备聚氨酯/分子筛复合材料及表征

采用预聚法制备了聚氨酯(PU)/沸石分子筛(zeo lite 13X)复合材料,并利用XRD、DSC和TG等手段表征了复合材料的晶态、硬链段的结晶及熔融温度、材料的耐热性能。结果表明,随着沸石分子筛在体系中加入量的增大,PU/13X复合材料的硬链段结晶度减小,而硬链段和软链段之间的混乱度增大,硬链段的结晶形态发生改变,晶面间距增大。力学性能测试表明,分子筛添加量小于7%时,拉伸强度和撕裂强度明显提高。     

多交联型聚氨酯材料的制备与性能

以聚酯多元醇(PEA)、2,4-甲苯二异氰酸酯(TDI-100)为原料,采用预聚法制备预聚体,将预聚体分成两部分分别以不同的扩链系数与扩链剂3,5-二甲硫基甲苯二胺(E-300)混合反应,再将两种配料不同的预反应物混合后浇铸成型,即为多交联体系聚氨酯材料。利用差示扫描量热(DSC)、耐溶剂性和力学测试考察其性能并与均一体系聚氨酯(PU)材料的性能进行比较。力学性能测试表明,多交联体系聚氨酯材料的耐撕裂性能明显提高,拉伸性能略微降低;多交联体系聚氨酯材料的耐溶剂性能也明显提高;DSC测定结果表明,多交联体系材料的微相分离更好。     

Synthesis and characterization of biodegradable polyurethane based on poly(?-caprolactone) and L-lysine ethyl ester diisocyanate

A biocompatible diisocyanate, lysine ethyl ester diisocyanate, was prepared. Afterwards, biodegradable polyurethane (PU) was synthesized by the step-growth polymerization of this diisocyanate with hydroxyl terminated poly(?-caprolactone) in the presence of 1,4-butanediol as a chain-extender. The resulting PU was characterized by GPC, IR and DSC measurements. Its mechanical strength was found to increase with increasing the hard segment content. The PU microfiber meshes with high porosity were obtained by solution electrospinning technique. Their degradation behavior in the PBS and enzymatic solution was also investigated.     

Synthesis and characterization of biodegradable polyurethane based on poly(ε-caprolactone) and L-lysine ethyl ester diisocyanate

A biocompatible diisocyanate, lysine ethyl ester diisocyanate, was prepared. Afterwards, biodegradable polyurethane (PU) was synthesized by the stepgrowth polymerization of this diisocyanate with hydroxyl terminated poly(ε-caprolactone) in the presence of 1,4-butanediol as a chain-extender. The resulting PU was characterized by GPC, IR and DSC measurements. Its mechanical strength was found to increase with increasing the hard segment content. The PU microfiber meshes with high porosity were obtained by solution electrospinning technique. Their degradation behavior in the PBS and enzymatic solution was also investigated.     

不同硬段含量的PU及其纳米复合材料

制备了不同硬段含量的聚氨酯(PU)及其PU/有机蒙脱土(OMMT)纳米复合材料。研究结果表明,随着PU分子链中硬段含量的增加,PU分子链的刚性提高,进入硅酸盐片层间的位阻增大,使插层变得困难,从而导致进入该硅酸盐片层间的PU分子链减少。OMMT对PU有增强增韧作用,但随着PU分子链中的硬段含量增加,OMMT的增强效果下降。PU及其PU/OMMT纳米复合材料的热稳定性均随着PU分子链中的硬段含量增加而下降。     

聚甲基乙撑碳酸酯产品中聚醚多元醇的提取及用于聚氨酯的合成

探讨了聚甲基乙撑碳酸酯(PPC)中副产物聚醚的提取方法,对其结构进行了红外光谱(FT-IR),核磁共振谱(1H-NMR)和凝胶渗透色谱(GPC)的表征,并进行了用其合成聚氨酯(PU)的应用研究。通过拉伸测试、邵氏硬度测试和热重分析(TG)考察了不同硬段比例、-NCO与-OH比例对所合成的PU的力学性能及热性能的影响。结果表明,当NCO∶OH略大于1时,随着硬段含量的增加,合成的聚氨酯的力学性能和邵氏硬度随之增加,T-5%、软硬段分解温度及玻璃化转变温度(Tg)无较大变化;当-NCO∶-OH值较低时,聚氨酯的力学性能、硬度及热性能均有降低的趋势。     

Evaluation on biocompatibility of biomedical polyurethanes with different hard segment contents

In this paper, polyurethane (PU) materials with different contents of hard segment (20%, 25%, 30%) were prepared based on hexamethylene diisocyanate and polycarbonate diols by solution polymerization. The obtained polycarbonate-urethane (PCU) elastomers were characterized by very good hydrophobic property and excellent resistance to hydrolysis. Hemolysis, recalification time and platelet-rich plasma adhesion were used to evaluate the blood compatibility of the materials. L929 cells cultured with leach?liquor of these PU membranes were selected to perform the cytotoxicity experiments. The results indicate that the hemolysis rates of PU membranes are all less than 5%, which can meet the requirement of the national standards for biomaterials. However, compared with 20% and 30% groups, the recalification time of the sample containing 25% hard segment is longer, while the number of platelet adhesion is less. Additionally, cells cultured in the leach liquor of PU membranes with 25% hard segment proliferated relatively more thriving, meaning that this proportion of the material has the lowest cytotoxicity.     

催化剂对异佛尔酮二异氰酸酯制备的脂肪族聚氨酯弹性体结构和性能的影响

采用一步法通过异佛尔酮二异氰酸酯与聚丙二醇和1,4-丁二醇反应合成了脂肪族聚氨酯（PU）弹性体。考察了催化剂的种类和含量对PU弹性体结构和性能的影响。结果表明,以辛酸亚锡为催化剂时,PU弹性体的软段相和硬段相间的相分离程度最明显且分子量最低,导致其力学性能最差;以辛酸铋为催化剂时,PU弹性体软段相和硬段相的相容性较好且...     

Thermal and tensile properties of HTPB-based PU with PVC blends

Blends of HTPB (hydroxyl-terminated polybutadiene)-based polyurethane (PU) and polyvinyl chloride (PVC) membranes with various relative weight percentages were prepared by solution process. Different equivalent ratios of HTPB, 4,4′-dicyclohexyl methane diiscyanate (H₁₂MDI), and 1,4-butane diol were used to synthesize PU solution by two-stage process. The intermolecular bonding between N-H, CO groups of PU and C-Cl group of PVC was determined via FTIR analysis by the relative absorbance of the two N-H groups and was correlated to thermal/mechanical properties. Larger part of PVC has been found to disperse in the hard domain of PU resulting in the shift in IR frequency. Thermal property, tensile strength and intermolecular bonding of membranes were function of the contents of PVC and PU's hard segment. One-year aged butadiene-containing PUs and blends still exhibit higher tensile strength than that of as-prepared ones. Hence, it is promising to replace the plasticizer, such as DOP, in PVC by these HTPB-based PU for the prevention of PVC migration as well as the enhancement of mechanical and thermal properties of blends.