鞋用聚氨酯胶粘剂的研究

探讨了研制高性能鞋用聚氨酯胶粘剂的技术路线,并介绍了聚酯多元醇和聚氨酯胶粘剂的合成工艺和方法。以聚己内酯、1,4-丁二醇和MDI等原料合成的鞋用聚氨酯胶粘剂,具有结晶度高、结晶速度快、内聚强度大等特点。讨论了聚酯二元醇、扩链剂、聚氨酯胶粘剂的分子量、异氰酸酯指数等对胶粘剂性能的影响。     

聚氨酯胶粘剂合成条件与结构性能关系的研究

在适当条件下,以PEA、PBA、PHA三种聚酯二醇与MDI反应,用溶液一步法合成了三个系列的线型嵌段聚酯型聚氨酯胶粘剂PEAU、PBAU、PHAU;采用IR,GPC、X射线、DSC和粘度测定等手段对它们进行了表征:研究了聚酯品种、聚酯分子量、聚氨酯分子量、聚氨酯分子中硬软段比例等因素对该类胶粘剂性能的影响。     

热塑性聚氨酯弹性体透明性影响因素研究

研究了采用不同类型的异氰酸酯、多元醇及扩链剂来合成热塑性聚氨酯弹性体（TPU）,讨论了软段多元醇的种类及分子量、硬段异氰酸酯的种类、扩链剂的种类及结构特点、增塑剂和微量水分等对TPU透明性的影响。结果表明,影响TPU透明性的主要因素是软段多元醇的种类及分子量、硬段异氰酸酯的种类。     

橡塑复合软管用聚氨酯胶粘剂

]本文合成了具有低固量、高粘度的橡塑复合软管用聚氨酯胶粘剂，并考察了异氰酸酯指数、扩链剂、聚酯多元醇分子量等因素对该胶粘剂性能的影响。     

软链段结构对聚氨酯弹性体胶粘剂性能的影响

合成了以聚己二酸-乙二醇聚酯二醇、聚己二酸-丁二醇聚酯二醇、聚己二酸-己二醇聚酯二醇为软链段的含羟基的聚氨酯胶粘剂样品。利用DSC和TEM等现代测试手段对聚氨酯胶粘剂的结晶行为和形态结构进行了表征。并探讨了软链段结构对聚氨酯胶粘剂粘接性的影响。     

装饰用聚氨酯胶粘剂的研究

研究了以聚氨酯为主体材料的装饰用胶粘剂的基础配方,考察了聚酯多元醇的分子量、扩链剂的用量、异氰酸酯的种类以及增粘树脂的种类。得出了较好的聚氨酯装饰用胶粘剂的基础配方:选择分子量为2500的PBA和MDI为原料,选择1．4-丁二醇为扩链剂(摩尔比BDO／PBA为0．4),溶剂为低毒混合溶剂,并添加10％左右的叔丁基酚醛树脂。此配方的剥离强度为100N／25mm,终粘强度为2．8MPa。     

MDI体系聚氨酯弹性体的力学性能研究

考察了多元醇种类、扩链交联剂配比及合成工艺等因素对MDI体系聚氨酯弹性体力学性能的影响。结果表明,使用聚酯类多元醇合成的聚氨酯弹性体力学性能较好;使用半预聚物法合成的聚氨酯弹性体较使用两步法合成的聚氨酯弹性体综合性能优异;扩链交联剂种类及硬段含量对聚氨酯弹性体力学性能起重要作用。     

软链段结构对聚酯弹性体胶粘剂性能的影响

合成了以聚已二酸－乙二醇聚酯二醇,聚已二酸－丁二醇聚酯二醇,聚已二酸－已二醇聚酯二醇为软链段的含羟基的聚氨酯胶粘剂样品,利用DSC和TEM等现代测试手段对聚氨酯胶粘剂的结晶行为和形态结构进行了表征,并探讨了软链段结构对聚氨酯胶粘剂粘接性的影响。     

新型PU革添加剂——PU革耐候耐黄新选择

<正>聚氨酯合成革(PU革)是目前世界上代替天然皮革制品最为理想的材料,主要应用于鞋、箱包、服装、家具、汽车、帐篷等领域。革用PU树脂属于弹性体范畴,由硬链段与软链段构成,通常用含羟基的聚酯或聚醚与异氰酸酯反应制得。生产中一般使用聚酯多元醇,其中以己二酸与乙     

1，3-丁二醇对PCL／MDI体系聚氨酯弹性体力学性能的影响

首先以聚己内酯多元醇（PCL）、4,4’-二苯基甲烷二异氰酸酯（MDI）、液化MDI和MDI-50为原料合成聚氨酯（PU）预聚体,再用混合扩链剂制备聚氨酯弹性体。讨论了预聚体异氰酸酯基（NCO）含量、异氰酸酯类型、1,3-丁二醇（1,3-BDO）含量、聚酯软段相对分子质量对聚氨酯弹性体力学性能的影响。结果表明：提高预聚体NC0基含量可使弹性体的硬度、300％定伸应力、拉伸强度和撕裂强度明显提高,拉断伸长率和冲击弹性则下降;纯MDI弹性体综合力学性能最好,液化MDI次之,MDI-50最差;提高1,3-BDO含量可使弹性体的硬度、撕裂强度和冲击弹性明显下降;软段相对分子质量为1000的聚氨酯弹性体的硬度、300％定伸应力、拉伸强度和撕裂强度较高,软段相对分子质量为2000的聚氨酯弹性体的拉断伸长率和冲击弹性较高。     

软段对热塑性聚氨酯弹性体结构及性能的影响

以二苯基甲烷-4,4′-二异氰酸酯(MDI)和扩链剂1,4-丁二醇(BDO)为聚氨酯弹性体硬段(控制硬段质量分数32%),以实验室自制聚己二酸乙二醇酯二醇(PEA)和聚己二酸乙二醇丙二醇酯二醇(PEPA)为软段,经预聚体法合成不同结构的热塑性聚氨酯弹性体(TPU)。研究了弹性体软段部分对其硬度、力学性能和结晶性能的影响。结果表明,控制热塑性聚氨酯弹性体硬段部分不变,改变软段,材料硬度变化不大;软段聚酯二元醇随其相对分子质量的增加,TPU力学性能和结晶性能均增强;研究不同PG含量的软段PEPA-TPU发现,当PG质量分数为10%时,TPU力学性能与结晶性能最好。     

Phase inversion and its effect on the properties of polyester polyurethane cationomers

Polyester polyurethane cationomers are prepared using polyester polyol of molecular weight 2000 as soft segments, N-methyl diethanolamine as chain extender, glycolic acid as quaternization agent, methyl ethyl ketone as solvent, and 4,4'-diphenylenemethylene diisocyanate (MDI) as diisocyanate. Properties of the films cast from solutions and emulsions are studied by infrared spectroscopy, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, and tensile-elongation testing. Ionization can cause phase separation and produces increased cohesion in the hard domains. The dispersion process can be divided into three stages involving a separation of hard segment aggregates due to adsorption of water on their surface, water entering into hard segment microionic lattics, and finally a rearrangement of agglomerates to form microspheres. The dispersion can disrupt the order in the hard domains and an increased phase separation.     

纤维级热塑性聚氨酯合成的研究

以聚己二酸乙二醇聚酯二醇（PFA）、4,4＇-二苯基甲烷二异氰酸酯（MDI）和1,4-丁二醇（BDO）为原料合成纤维级热塑性聚氨酯,研究了低聚物分子质量、硬段含量、反应温度以及物料含水量对热塑性聚氨酯（TPU）性能的影响,得出了三颈瓶法合成纤维级TPU的最佳配方和合适的反应条件。     

The role of diisocyanate structure on microphase separation of solution polymerized polyureas

Three diisocyanates with different symmetry and planarity (2,6-TDI, 2,4-TDI and MDI) were used to synthesize polyureas with the same oligomeric polyetheramine having a molecular weight of ∼1000 g/mol. The influence of diisocyanate symmetry on the phase separated morphology, hydrogen bonding behavior, and molecular dynamics were investigated. Symmetric diisocyanate structures facilitated self-assembly of hard segments into ribbon-like domains, driven by strong bidentate hydrogen bonding. The hard domains for the 2,6-TDI polymer appear to be continuous in AFM images, while the persistence length of the hard domains in the 2,4-TDI and MDI polymers gradually decrease, and fewer hard domains are apparent with decreasing hard segment symmetry. The extent of hard/soft segment demixing, assessed from small-angle X-ray scattering, was very incomplete for all of the polyureas and is significantly influenced by hard segment structure. For the 2,4- and 2,6-TDI polyureas, two segmental relaxations were observed using dielectric relaxation spectroscopy; one arising from relatively unrestricted motion in the soft segment rich phase, and a slower process associated with segments in the soft phase constrained by their attachment to hard domains.     

Thermal stability of polyurethane elastomers before and after UV irradiation

In this work, we investigated the thermal degradation behavior of segmented polyurethane (PUR) elastomers before and after UV irradiation. The thermal degradation of PUR elastomers was studied over the temperature range of 25–600°C in an atmosphere of nitrogen using thermal gravimetric analysis (TGA). Four series of PUR elastomers derived from poly(oxytetramethylene)glycol (PTMO) of 1000 and 2000 molecular weight and poly(caprolactone glycol) (PCL) of 1250 molecular weight, 4,4′‐diphenylmethane diisocyanate (MDI), and 4,4′‐dicyclohexylmethane diisocyanate (H₁₂MDI) and 1,4‐butanediol as an chain extender were synthesized by the prepolymer method. The derivative thermogravimetric (DTG) peaks observed in the experiments indicated that PUR elastomers degraded through two steps. We attributed the first step to degradation of the hard segment. The second degradation step could be ascribed to degradation of the soft segment. We found that the PUR elastomers based on poly(ester polyol) and aromatic diisocyanate exhibit better thermal stability than that of PUR elastomers based on the poly(ether polyol) soft segment in both steps of degradation. The thermal degradation is more prevalent in PUR elastomers based on cycloaliphatic diisocyanate. The higher values of the temperature of initial decomposition (Tⁱ) indicate a higher thermal stability of UV‐exposed elastomers on the beginning of degradation. This may be due to the formation of a crosslinking structure in the presence of UV irradiation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 864–873, 2001     

Properties of polyisobutylene polyurethane block copolymers: 2. Macroglycols produced by the ‘inifer’ technique

The structure-property relationships of a series of 4,4′-diphenylmethane diiscoyanate (MDI) based polyisobutylene (PIB) polyurethanes were investigated. The PIB glycol was synthesized via the ‘inifer’ technique and had a narrow functionality distribution with a number average functionality of 2.0. The use of a PIB glycol with improved functionality and solution polymerization of the polyurethane led to improved mechanical properties compared with previously studied PIB polyurethanes. However, the mechanical properties were still low compared with conventional polyurethanes; the absence of soft segment strain-induced crystallization and compositional heterogeneity due to reactant incompatibility are cited as possible causes of low mechanical properties. Sample compositions were designed for independent investigation of the effects of hard segment content and soft segment molecular weight on the properties of the materials. Increasing hard segment content resulted in improved dynamic and tensile modulus, lower elongation at break, and larger hard segment domains. Increasing soft segment molecular weight led to larger domains and reduced mechanical properties. The degree of phase separation as measured by the soft segment T_g and the amount of interfacial mixing measured by small angle X-ray scattering (SAXS) were unaffected by hard segment content and soft segment molecular weight and were indicative of a high degree of phase separation compared with conventional polyurethanes.     

4,4’-二氨基二苯醚扩链的聚氨酯应力松弛行为

以不同相对分子质量(Mn)的聚四氢呋喃二元醇为软段、4,4’-二苯甲烷二异氰酸酯和扩链剂4,4’-二氨基二苯醚为硬段,合成了一系列聚氨酯(PU)样品.从唯象的角度,利用标准线性粘弹(SLV)模型研究了其应力松弛特性,根据SLV模型的本构方程,计算出PU的两个松弛时间τ1和τ2,分析了软段Mn与硬段含量对其松弛行为的影响...     

Photostability of polyetherurethaneureas

Polyetherurethaneureas (PEUUs) were synthesised from polyethylene-glycols (PEGs) of molecular weight 400, 600 and 1000, 4,4′-diphenylmethanediisocyanate (MDI) and aliphatic diamine chain extenders, 1,3-propanediamine (PDA) and 1,6-hexanediamine (HDA). Polymer films were irradiated with 365 nm light at 293 K and the effects of polyether soft segment length and urea hard segment on photo-oxidative stability were studied by following the variation in weight-average molecular weight (M _w), gel formation and stress-strain properties. Changes in ultraviolet and infrared spectroscopy were monitored on photo-oxidation and hydroperoxide content determined. The soft segment length was increased by increasing the molecular weight of PEG from 400 to 1000 and hard segment structure was changed by variation of diamine. It was noted that the structure of urea and polyether soft segment length plays an important role in photostability of PEUUs. PDA chain extended PEUUs were more stable than HDA chain extended PEUUs.     

Inelastic response of copolyurethane elastomers with varying soft segment molecular weights and preparation procedure

A family of thermoplastic polyurethane elastomers (TPUs) based on the soft segment poly(oxytetramethylene) (PTMO₂₀₀₀ and PTMO₁₀₀₀) were synthesized by the one‐shot and prepolymer methods. Two hard segments were chosen, 4,4′‐methylenebis(phenyl isocyanate) (MDI) (non‐crystallizable) and 4,4′‐dibenzyl diisocyanate (DBDI) (crystallizable). Microphase separation and crystallinity were investigated using small‐angle X‐ray scattering and wide‐angle X‐ray scattering, and dynamic viscoelastic properties were also determined. An increased hard phase degree of crystallinity was primarily achieved by use of DBDI instead of MDI, regardless of the preparation procedure and soft segment molecular weight. An increase of the molecular weight leads to an increase in phase separation and to a decrease in hysteresis. For the DBDI based polymers, a lower soft segment molecular weight resulted in an increase in crystallinity. The DBDI series of TPUs obtained by the one‐shot and prepolymer methods showed higher hysteresis and residual elongations compared with the corresponding materials achieved with MDI. Although the materials varied widely in response to first loading, regardless of the preparation procedure, they displayed remarkable reproducibility and commonality in cyclic responses within the maximum strain envelope. The thermomechanical experiments revealed a better thermal behavior with increase of the soft segment molecular weight from PTMO₁₀₀₀ to PTMO₂₀₀₀.© 2013 Society of Chemical Industry     

Thermosetting polyurethanes with water‐swollen and shape memory properties

A series of shape memory polyurethanes (SPU) with different component ratio of PEG, MDI, BDO, and crosslinker DEA were synthesized by stepwise polymerization in DMF. WAXD, SAXS, DMTA, and DTA were used to study the microphase structure of SPU. No obvious phase‐separation and crystalline evidence of the PEG soft segment and hard segment were obtained in this work. The water‐swollen ratio increases with both the increasing molecular weight of PEG soft segment and the decreasing density of the chemical crossbonding. All the samples show good thermally stimulated shape memory properties. When the molar ratio of soft segment to hard segment is close, the shape recovery time reduces along with the increasing density of the chemical crossbonding. When the densities of the chemical crossbonding are similar, the shape recovery time reduces with the increasing molecular weight of the PEG soft segment. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1504–1512, 2002; DOI 10.1002/app.10357