扩链剂在阻燃高回弹聚氨酯泡沫中的应用

分别采用三乙醇胺(TEOA)、二乙醇胺(DEOA)和甘油(GLY)三种扩链剂制备阻燃高回弹聚氨酯(FRHRPU)泡沫塑料.探讨了TEOA,DEOA,GLY对FRHRPU泡沫塑料反应活性、泡孔结构及制品力学性能的影响.结果表明:以DEOA为扩链剂制备的FRHRPU泡孔孔径为200.00 μm、氧指数为28.7％,工艺稳定性及力学性能优于其他两种扩链剂制备的FRHRPU.DEOA可广泛应用于FRHRPU泡沫塑料.     

二醇扩链剂对聚醚聚氨酯弹性体性能的影响

研究了以乙二醇、一缩二乙二醇、1,4-丁二醇和1,6-己二醇作为扩链剂对聚醚聚氨酯弹性体性能的影响。结果表明,扩链剂链长越短,弹性体的微相分离程度和力学性能越好;以BDO扩链为例,随其用量的增加,弹性体的性能提高,达到一定值后再增加用量性能反而下降;混合扩链剂有助于聚氨酯弹性体综合性能的提高。     

水分散有机硅-聚氨酯嵌段共聚物的制备与性能研究

以端羟基聚二甲基硅氧烷（PDMS）和氨烃基硅烷偶联剂（DB-912）为原料,合成了端氨烃基聚二甲基硅氧烷低聚物（NS）,并以此作为扩链剂,制备了水分散有机硅-聚氨酯嵌段共聚物（WPSUR）。考察了NS的摩尔质量与扩链剂类型对乳胶粒粒径、薄膜疏水性与耐热稳定性的影响。结果发现,随着NS摩尔质量的增加,乳液粒径增大;扩链剂类型对乳液及薄膜性能影响较大,采用NS为扩链剂制备的WPSUR,乳液呈现较高的表现黏度,薄膜吸水率较低、对水的表面接触角达103°,疏水性较好;与引入小分子硅烷偶联剂的体系相比,体系中有机硅链段含量大大增加,耐热稳定性良好;水分散液均呈现良好的离心稳定性,乳液具有良好的耐高温性能与冰冻-解冻稳定性。     

PEPA/MDI体系聚氨酯弹性体力学性能的研究

以聚已二酸乙二醇丙二醇酯（PEPA）、4，4＇-二苯基甲烷二异氰酸酯（MDI）为原料，用1，4-丁二醇（BDO）扩链剂或混合扩链剂制备了聚氨酯（PU）弹性体。讨论了预聚体NCO基质量分数、扩链剂和催化剂用量对聚氨酯弹性体力学性能的影响；同时，比较了MDI／BDO体系与2，4-甲基二异氰酸酯／3，3＇-二氯-4，4＇-二胺基二苯甲烷（TDI／MOCA）体系的性能。结果表明，聚氨酯弹性体的硬度、模量和强度随预聚体NCO基含量增加而增加;提高扩链剂的三元醇含量，弹性体力学性能呈下降趋势;MDI／BDO体系的扯断伸长率和撕裂强度比TDI／MOCA体系高。     

PLA/PBAu嵌段共聚物合成工艺优化及降解性能

以端羟基聚乳酸（PLA）、聚己二酸-丁二醇-尿素（PBAu）为预聚物,六亚甲基二异氰酸酯（HDI）为扩链剂,制备出一种新型PLA/PBAu嵌段共聚物。研究了扩链剂用量、扩链温度以及催化剂用量对PLA/PBAu嵌段共聚物分子量的影响,确定了合成PLA/PBAu嵌段共聚物的最佳工艺条件。采用核磁共振、凝胶渗透色谱、差示扫描量热仪、扫描电镜等对共聚物薄膜结构及性能进行表征。结果表明：成功合成了PLA/PBAu嵌段共聚物,分子量可达10×10⁴,玻璃化转变温度约为41℃;并且随着PBAu含量的增加,共聚物的结晶度逐渐增加。以NaOH溶液为模拟液进行加速降解实验发现,当PBAu含量为30%时,可以显著提高嵌段共聚物的降解速率,并且通过调节PLA、PBAu预聚物的含量,可以控制嵌段共聚物的降解速率。     

尿素对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯（IPDI）、聚醚220、聚酯二元醇为主要原料,二羟甲基丙酸（DMPA）为亲水性扩链剂,并分别用乙二胺和尿素作扩链剂,合成阴离子型水性聚氨酯乳液。对比2种扩链剂对水性聚氨酯乳液黏度、膜吸水性及玻璃化转变温度（Tg）的影响.结果表明,增加乙二胺的用量,能提高聚氨酯乳液黏度,降低其膜的吸水性,增大聚合物Tg．而增加尿素的用量对聚氨酯乳液黏度和聚合物Tg没有明显影响,但提高了膜吸水性。说明尿素没有起到扩链作用,但可以作为封端剂在聚氨酯分子末端引入胺基。     

扩链方式及扩链剂用量对PU/PVC复合树脂性能的影响

首先制备自乳化阴离子水性聚氨酯(PU),然后以此为种子原位接枝共聚氯乙烯制备PU/PVC复合乳液树脂.通过动态激光粒度分析仪、动态力学分析仪(DMA)和TA-2000热分析仪研究了扩链方式以及扩链剂用量对PU粒径及其分布、乳液PU的动态力学性能和PU/PVC复合树脂耐热稳定性的影响.结果表明:分散时扩链所得到的PU乳液粒径较小,且随着扩链剂用量的增加粒径逐渐增大;预聚时扩链,扩链剂用量较高时聚氨酯的玻璃化转变温度较低;预聚时扩链的PU/PVC复合树脂的热稳定性较好,但随着扩链剂用量的增加耐热性下降.     

扩链PBS的微孔发泡行为研究

以聚丁二酸丁二醇酯（PBS）为基体,加入不同含量的扩链剂,通过熔融共混法制备扩链PBS样品。随后以超临界CO₂作为物理发泡剂,通过釜压发泡法在87 ℃下对PBS进行物理发泡。结果表明,随着扩链剂含量的增加,PBS的结晶温度先升高后略微下降,结晶度略微提高,黏弹性改善;随着扩链剂含量的增加,泡孔尺寸和发泡倍率逐渐减小,泡孔密度逐渐增加;当扩链剂含量为8 %（质量分数,下同）时制备的扩链PBS微孔泡沫的泡孔尺寸为9.2 μm,泡孔密度为1.93×10⁹ 个/cm³。     

松香基荧光水性聚氨酯的制备及性能

以异佛尔酮二异氰酸酯（IPDI）、丙烯酸松香加成物与甲基丙烯酸2-羟乙酯酯化物（RAG）为原料,二羟甲基丙酸（DMPA）为亲水扩链剂,5,7-二羟基-4-甲基香豆素（DHMC）为荧光扩链剂,成功制备了稳定性好的松香基荧光水性聚氨酯乳液（FWPU）。采用核磁共振氢谱、红外光谱、紫外光谱等对FWPU进行了结构表征,探讨了DHMC用量、猝灭剂1,4-对苯二酚（HQ）对FWPU荧光性能的影响,测试了聚氨酯膜的紫外防护性能。结果表明,DHMC成功接枝到聚氨酯主链上,随着其用量的增加,FWPU的荧光强度逐渐增大,用量为1%时荧光强度最大（达5002）;相比于DHMC,FWPU的荧光强度明显增大;HQ对FWPU荧光猝灭效果明显。加入DHMC,聚氨酯的紫外线防护系数从6.86增加到12.27,紫外防护性能得到改善,耐水性也有一定的提高。     

磁鼓刮板用聚氨酯弹性体的制备及性能研究

采用低聚物多元醇和二异氰酸酯合成预聚体,以3,5-二甲硫基甲苯二胺（E-300）为扩链剂,加入内掺型抗静电剂制备了磁鼓刮板用聚氨酯弹性体（PUE）。讨论了低聚物多元醇和异氰酸酯类型、预聚体NCO含量、扩链系数（NH,／NCO摩尔比）和抗静电剂加入量对PUE性能的影响。结果表明,当采用聚四氢呋喃醚二醇（PTMG-1000）、甲苯二异氰酸酯（TDI-100）为原料,预聚体NCO质量分数为5．50％、扩链系数为O．95、抗静电剂用量为5％时,制得的PUE具有优良的力学和抗静电性能,能够满足磁鼓刮板的应用要求。     

泡沫稳定剂在阻燃高回弹聚氨酯泡沫塑料中的应用

分别采用L-5 333,Y-10 366和B-8716三种泡沫稳定剂制备阻燃高回弹泡沫塑料;探讨了泡沫稳定剂对阻燃高回弹聚氨酯（FRHRPU）组合料反应活性、泡孔结构及制品力学性能的影响。结果表明：泡沫稳定剂Y-10 366制备的FRHRPU的拉伸强度为171.18 kPa,撕裂强度为3.23 N/cm和回弹性为58.70%,均高于其他两种硅油的,并且当Y-10 366与多元醇的质量比从0.5/100增加到1.2/100时,制品的泡孔孔径先减小后增大,而制品的开孔率从93%降低到35%。     

Structure–properties relations in flexible polyurethane foams containing a novel bio-based crosslinker

The structure, morphology and properties of PU foams containing the novel bio-based crosslinker 3-hydroxy-N,N-bis(2-hydroxyethyl)butanamide (HBHBA) were investigated in comparison with PU foams containing the conventional crosslinker diethanolamine (DEOA). FTIR results indicate that HBHBA increases the degree of microphase separation in the foam and hydrogen bond concentration in the hard domains, suggesting that the incorporation of HBHBA produces better ordering of hard domains as compared with DEOA-crosslinked foam. Uniquely, the tri-functional crosslinker, HBHBA, can act as a chain extender due to the presence of a low reactivity secondary hydroxyl, reducing the crosslink density of the HBHBA foam vs. that of DEOA foam. Concerning foam morphology, the lower reactivity of HBHBA tends to favor larger cell sizes and more complete cell opening as compared to the more reactive DEOA. This behavior may in turn be related to the onset of phase separation and the rate of viscosity build-up. Mechanical properties measurements indicate that the elongation at break and the tensile strength of the HBHBA foam are ∼33% and 41% higher than the DEOA foam, respectively. The HBHBA foam also exhibits 40% greater tear strength and 10% greater compression strength without any loss in resilience. These results indicate that this bio-based crosslinker enhances properties and has clear potential in molded foam applications.     

扩链改性对聚乳酸注塑发泡成型的影响

通过添加不同含量的扩链剂（CE）对2种牌号聚乳酸（PLA）进行改性,对改性PLA进行注塑发泡,研究了扩链剂用量对PLA熔体流变性能、试样的泡孔形态和力学性能等的影响,并比较了不同PLA泡沫的泡孔结构和力学性能的差异。结果表明,PLA的熔体流动速率随着扩链剂的加入明显降低,同时熔体强度得到提高;随着扩链剂含量的增多,注塑级和挤出级PLA的发泡效果和力学性能都逐渐提高,扩链剂含量达到0.8 %（质量分数,下同）时,取得最好的泡孔结构和最优的力学性能;改性注塑级发泡试样较改性挤出级发泡试样有更高的力学性能。     

Reactively Modified Poly(lactic acid): Properties and Foam Processing

Summary: In order to produce modified poly(lactic acid) (PLA) resins for applications requiring high melt viscosity and elasticity (e.g., low‐density foaming, thermoforming), a commercial PLA product has been reactively modified in melt by sequentially adding 1,4‐butanediol and 1,4‐butane diisocyanate as low‐molecular‐weight chain extenders. By varying amounts of the two chain extenders associated to the end group contents of PLA, three resulted samples were obtained. They were then structurally characterized by FTIR spectroscopy and molecular structure analysis. Their thermal, dynamic mechanical thermal properties and melt viscoelastic properties were investigated and compared along with unmodified PLA. The results indicated that chemical modification may be characterized as chain scission, extension, crosslinking, or any combination of the three depending on the chain extender amounts. The increase of PLA molecular weight could be obtained by properly controlling amounts of two chain extenders. The samples with increased molecular weights showed enhanced melt viscosity and elasticity. Such property improvements promised a successful application for modified PLA in a batch foam processing by producing foams with reduced cell size, increased cell density and lowered bulk foam density in comparison with plain PLA foam.

Cellular morphology of a modified PLA foam.     

Studying the effects of chain extenders chemical structures on the adhesion and mechanical properties of a polyurethane adhesive

Chain extenders including diethanol amine (DEA) and 2-cyano-N,N-bis-hydroxyethyl acetamide (CNBA) were utilized to enhance the adhesion and mechanical properties of a polyurethane (PU) adhesive. The adhesion and mechanical properties of the adhesives were studied by peel test, tensile test and dynamic thermal analysis (DMTA) respectively. Results revealed that both chain extenders (DEA and CNBA) increased peel test modulus. The cross-linking density and toughness of the adhesive were significantly increased using chain extenders. Results showed that chain extender without side chain (DEA) could improve the adhesion and mechanical properties of the adhesive greater than chain extender with aliphatic side group (CNBA).     

The Effect of Chain Extender Type on the Physical,Mechanical, and Shape Memory Properties of Poly(ε-Caprolactone)-based Polyurethane-ureas

A series of segmented polyurethane-ureas were synthesized, based on poly(ε-caprolactone), hexamethylenediisocyanate, and different chain extenders. The effect of chain extender on physical, mechanical, and shape memory properties of the polyurethane-ureas was examined at constant hard-to–soft–segment molar ratio. Polyurethane-urea from piperazine showed higher degree of phase separation, mechanical characteristics, shape fixity, and shape recovery temperature than polyurethane-ureas from aliphatic chain extenders. Furthermore, the degree of phase separation was decreased by increasing of chain length of aliphatic chain extenders. This was attributed to the dissimilar compatibility and flexibility of the hard segments, resulting from different chain extenders.     

发泡工艺对高回弹聚氨酯泡沫塑料力学性能的影响

采用自制聚合物聚醚多元醇(POP-A)和聚醚多元醇(KGF5020)与异氰酸酯(PM200/TDI)体系制备一种高回弹聚氨酯泡沫塑料。探讨了发泡工艺对其力学性能的影响。确定了最佳发泡工艺:m(H2O)∶m(A-1)∶m(A-33)∶m(多元醇)为(3.0～3.5)∶0.15∶0.30∶100;采用Y-10366为泡沫稳定剂,DEOA为扩链剂。聚醚中KGF5020以及异氰酸酯中TDI的质量分数为50%。异氰酸酯指数大于1.02,模具的温度为65℃,室温下熟化时间为72h。在此条件下制品的力学性能:拉伸强度为171kPa,断裂伸长率为230%,回弹率为58.7%,Tg为47℃,撕裂强度为3.2N/cm,压陷因子为2.3,氧指数为28。     

Influence of diethanolamine (DEOA) on structure–property behavior of molded flexible polyurethane foams

In this study, the viscoelastic and morphological properties of molded foams were investigated to determine the influence of varying the concentration of diethanolamine (DEOA), a commercially utilized crosslinking agent. FTIR and WAXS analyses showed that DEOA had a disrupting effect on the bidentate hydrogen bonding within the hard domains of the polymer. DMS revealed that DEOA softens the foam above the T_g of the soft segment but only causes minor changes in the degree of microphase separation. Annealing treatments were shown to remove the DEOA influence on the microphase separation as well as some of the softening effect. FTIR was used to show that bidentate hydrogen bonding is enhanced through the annealing of DEOA foams. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 202–216, 2000     

高速铁路轨下弹性垫板的研制

通过4,4'-二苯基甲烷二异氰酸酯(MDI)、组合聚醚多元醇、匀泡剂、扩链剂和水反应制备高速铁路轨下弹性垫板(UTPE).探讨了聚醚多元醇相对分子质量、交联剂种类、硬段含量等对UTPE力学性能、静刚度的影响.并结合特别模具和加工工艺研制了高速铁路轨下弹性垫板,经测试得知,它可满足要求.