不饱和聚酯片状模塑料的研究

采用聚氨酯预聚物作增稠剂对带端羟基的不饱和聚酯进行增稠,制备出一种新型的不饱和聚酯片状模塑料(SMC),并研究了其增稠性能、增韧性能及贮存稳定性。结果表明,增稠剂PU400的用量要控制在8％～10％,否则树脂糊无法正常浸渍玻璃纤维;不饱和聚酯SMC的体积收缩率随PU400加入量的增加而明显变小;当PU400含量为36％,时,不饱和聚酯SMC固化物的拉伸强度、断裂伸长率、冲击强度都维持在一个较高的水平;该不饱和聚酯SMC有良好的贮存稳定性。     

端异氰酸酯基PU增稠端羟基不饱和聚酯SMC的研究

本文以端异氰酸酯基聚氨酯(PU)预聚物为增稠剂对端羟基不饱和聚酯树脂(UPR)进行增稠，通过红外分析和相容性测试对增稠机理进行了研究，在此基础上制备出以PU增稠端羟基不饱和聚酯的片状模塑料(UPR／PU—SMC)，并对其力学性能进行测试。结果表明：PU预聚物的-NCO基与UP树脂上的羟基反应形成高分子量的线形氮基甲酸酯结构而增稠，随着WPU值变化，PU与UPR的相容性有较大变化，而当WPU=36％时，UPR—PU—SMC的各项力学性能都能达到较高值。     

聚氨酯改性不饱和聚酯的徽观结构与性能

利用与天然纤维具有良好亲和性的聚酯聚氨酯(PU)改性不饱和聚酯(UP),通过扫描电镜（SEM）、傅里叶红外光谱（FT-IR）、接触角和力学性能等,研究了改性不饱和聚酯的微观结构、反应程度和主要性能.研究结果表明,引入PU提高了不饱和聚酯树脂的韧性,增加了与天然纤维的界面浸润性,降低了不饱和聚酯树脂的固化收缩率.所得改性不饱和聚酯的冲击断裂截面表现为韧性断裂;与天然纤维的接触角随着聚氨酯添加量的增加而降低,表明改性不饱和聚酯与天然纤维的浸润性增强.力学性能测试表明,当PU含量为5%时,其冲击强度可提高80%,弯曲模量降低小于20%,固化收缩率低于4%.     

SMC中不饱和聚酯的增稠

本文研究了碱土金属氧化物对不饱和聚酯的增稠机理。增稠聚酯的红外吸收光谱表明,增稠是形成中性盐的结果。阐述了增稠剂的选择和使用及对增稠速度的影响,以及增稠时应该注意的问题。     

异氰酸酯与不饱和聚酯的嵌段共聚改性

通过分子结构设计先合成了低平均聚合度端羟基不饱和聚酯(UP),再与异氰酸酯(PU)共聚反应,得到了一种异氰酸酯嵌段改性不饱和聚酯树脂。通过力学性能测试和红外光谱分析研究了UP/PU共聚体各合成反应阶段分子官能团的变化,醇酸比、二元醇种类对UP齐聚物的平均聚合度和粘度的影响,UP/PU共聚体中PU链段对固化后树脂力学性能的影响以及其玻纤复合材料的性能。结果表明,UP/PU浇铸体及玻纤复合材的拉伸强度分别为75MPa,956MPa,弯曲强度分别为116MPa,1220MPa,UP/PU共聚改善了现有不饱和聚酯树脂脆性大、固化收缩率高及与玻璃纤维的粘结性差等缺点。     

不饱和聚酯树脂增稠特性的研究

采用旋转流变仪研究了增稠剂的种类和用量、增稠温度以及填料种类等对不饱和聚酯树脂(uP)增稠体系粘度的影响,分别通过酸值滴定和红外分析等手段探讨了Mgo和MDI的增稠机理,结果表明,四种增稠剂的增稠速度不同,其中MgO最快;增加增稠剂的用量均可加快增稠速度,增稠速度也随增稠温度的增加而加快;填料的加入使得体系的粘度迅速增大.并且不同种类的填料对体系粘度的影响不同,与CaCO3相比,ATH使体系的粘度增加更多.因此工业生产中要综合考虑各方面因素,以获得合适的增稠工艺.     

SMC/BMC制备中树脂糊的粘度控制

本文研究了在SMC／BMC制作过程中分散剂氧化镁和二异氰酸酯化合物对树脂糊增稠特性的影响，通过树脂糊的粘度变化，考察新型增稠体系的增稠性能和片材的贮存稳定性。本研究对于改进SMC／BMC的成型压力、片材流动、制品质量、模塑料的贮存使用期有一定的指导意义。     

聚合MDI改性BMC研究

以聚合MDI作为增稠剂改性团状模塑料(BMC),考察了聚合MDI用量增稠不饱和聚酯树脂(UP)和聚合MDI增稠不同质量比的不饱和聚酯树脂(UP)/环氧乙烯基树脂(VE)的混杂树脂对BMC物理性能的影响。结果表明,聚合MDI的加入能改善BMC的物理性能,聚合MDI增稠VE时,当质量分数为6%时,BMC的拉伸、弯曲和冲击强度均达到最大,收缩率最小;聚合MDI增稠UP/VE混杂树脂时,UP/VE质量比在25/45到35/35时,能获得最小的收缩率和力学性能。     

联合增稠对不饱和聚酯团状模塑料流变行为的研究

模压流变性能是不饱和聚酯团状模塑料(BMC)在工业压制过程中相当重要的工艺参数。传统的BMC制造工艺,由于模压过程中流变性能较差,需要较大的模压压力及较长的模压时间,这样既增大了模具损耗,也降低了工厂的生产效率。系统讨论了化学增稠剂Ca(OH)_2在模压过程中对BMC流变行为的影响,在此基础上利用结晶性树脂与Ca(OH)_2对BMC进行联合增稠,对联合增稠的BMC的平板流动性能及螺旋流动性能进行分析。结果表明,结晶性树脂与Ca(OH)_2搭配的复合增稠体系不会影响BMC的固化行为,同时可以较好地改善BMC的模压流动性能,实现低压条件下BMC的成型。     

硅灰石在不饱和聚酯树脂中的应用

对针状硅灰石（L：D≥10，325目及800目）提纯后，采用硅烷偶联剂进行表面处理，用活化指数对改性效果进行评价，确定了偶联剂的最佳用量，将硅灰石按不同比例填充于不饱和聚酯树脂体系中，研究了材料的性能，比较了不同粒径硅灰石对材料性能的改善效果。结果表明：改性后的硅灰石可显著改善不饱和聚酯的性能。800目硅灰石比325目硅灰石对不饱和聚酯树脂的性能改善效果更好。当800目硅灰石的添加量在30％－40％之间时，硅灰石填充不饱和聚酯复合体系经基体树脂的拉伸强度增加1．95倍，弯曲强度增加1．47倍。     

低压片状模塑料增稠工艺研究

采用氧化镁为增稠剂、结晶树脂以粉料形式加入而降低片材热模内粘度的工艺，改进了对低压片状模塑料的增稠方法。结果表明：采用此工艺，设备不需要加热，增稠符合传统SMC增稠曲线；片材在模腔内有较低的粘度，适宜于低压成型。     

Preparation of polyurethane wood adhesives by polyols formulated with polyester polyols based on castor oil

The aim of this work was the synthesis of polyester polyols from renewable sources as one of the important compounds of polymeric polyurethane (PU) adhesives. The polyester polyols were synthesized by condensation polymerization of different dicarboxylic acids with castor oil and the reaction conditions were in agreement with green chemistry principles. The preparation of PU wood adhesives was carried out by the reaction of each obtained polyester polyol with 4, 4′-diphenylmethane diisocyanate (MDI). The adhesive performance was improved by mixing the obtained polyester polyols with polypropylene glycol (PPG 400) and butanediol (BD). Different NCO/OH ratios were used to obtain adhesives with appropriate properties. The structures of the synthesized polyesters and adhesives were characterized by FTIR, thermogravimetric analysis (TGA) and lap shear strength values were also determined in various conditions such as cold water, hot water, acid and alkali solutions.     

耐水解聚醚-聚酯型聚氨酯涂饰剂的研制

以聚四氢呋喃醚二醇（PTMG）、聚酯多元醇和二苯基甲烷二异氰酸酯等为主要原料，合成了一种聚醚-聚酯共聚型氨酯树脂，以该聚氨酯树脂、颜料及混合有机溶剂等原料，配制了耐水解聚氨涂饰剂，该聚氨酯涂饰用于聚氨酯合成革的表面涂饰。重点讨论了聚氨酯树脂聚醚含量对树脂物性、耐水解性能的影响，以及树脂的100%模量、粘度及涂饰剂溶剂体系对涂饰加工性能及合成革耐水解性能的影响，制得的聚氨酯涂饰具有良好的耐水解性能。     

Thermo gravimetric analysis and morphological behavior of castor oil based polyurethane–polyester nonwoven fabric composites

Castor oil (CO) based polyurethane (PU)– polyester nonwoven fabric composites were fabricated by impregnating the polyester nonwoven fabric in a reactive composition containing CO and diisocyanate. Composites were fabricated with two different isocyanates such as toluene‐2, 4‐diisocyanate (TDI) and hexamethylene diisocyanate (HMDI). Thermogravimetric analysis (TGA) studies of the composites were performed to establish the thermal stability and their mode of thermal degradation. It was found that degradation of neat PU takes place in two steps and that of polyester nonwoven fabric reinforced PU composites takes place in three steps. From the TGA thermograms, a little improvement in thermal stability incase of polyester nonwoven fabric reinforced PU composites were noticed compared to unreinforced PUs. Degradation kinetic parameters were obtained for the composites using Broido, Coats and Redfern, and Horowitz and Metzger methods. Tensile fractured composite specimens were used to analyze the morphology of the composites by scanning electron microscopic technique. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

蓖麻油改性无溶剂型双组分聚氨酯复膜胶

以蓖麻油、苯酐和二甘醇等为原料,经酯化、缩聚后,合成了蓖麻油改性聚酯多元醇,并以此作为复膜胶的固化剂;以MDI-50(二苯基甲烷二异氰酸酯)、PPG-2000/PPG400(聚醚二元醇)为原料,合成了端-NCO基聚氨酯(PU)预聚体,并以此作为复膜胶的主剂;将主剂和固化剂按一定比例混合后,制得无溶剂型双组分PU复膜胶。研究结果表明:当反应温度为45℃、反应时间为3 h和w(-NCO)=18%时,主剂的黏度、流动性相对最好;当双组分中n(-NCO)∶n(-OH)=1.9∶1、固化温度为50℃、固化时间为24 h和w(蓖麻油)=28.3%时,复膜胶的粘接性能相对最好,并且接近于进口同类产品。     

Analysis of unsaturated polyester-polyurethane interpenetrating polymer networks. I: Reaction kinetics and viscosity model

The reaction kinetics and viscosity behavior during the reaction injection molding (RIM) process of unsaturated polyester (UPE)-Polyurethane (PU) interpenetrating polymer networks (IPNs) were studied. The interaction between the reactants of the component polymers was reflected in the reaction kinetic model. The intermediate reaction products having a certain conversion level were prepared in order to obtain the conversion dependence of viscosity. The composition dependence of blend viscosity was also evaluated for, the oligomeric mixture.     

Method for improving the mechanical performance and thermal stability of unsaturated polyester resin/waste‐printed circuit board nonmetals composites via isocyanate chemistry

To strengthen the interfacial interactions between waste‐printed circuit board (WPCB) nonmetals and unsaturated polyester resin (UPE) and achieve a high performance in UPE composites, a novel type of polyurethane prepolymer (pre‐PU) with dual functions was prepared by the reaction of isophorone diisocyanate with poly(ethylene glycol). We found that pre‐PU was chemically bonded to the surface of the WPCB nonmetals, and a stronger interaction between the WPCB nonmetals and UPE matrix was formed. The mechanical properties and thermal stability of the UPE/pre‐PU–WPCB nonmetal composites showed remarkable improvements compared with those of the UPE/WPCB nonmetals composites, in particular, the impact toughness, which increased threefold. We envision that this promising modification method will not only open up new opportunities for the preparation of high‐performance plastic composites but also provide a guarantee for the practical industrial application of WPCB nonmetals. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45129.     

Degradable polyurethane based on star-shaped polyester polyols (trimethylolpropane and ɛ-caprolactone) for marine antifouling

The star-shaped polyester polyols based on initiators (trimethylolpropane or pentaerythritol) and ɛ-caprolactone were prepared by polycondensation reaction. The degradable polyurethane (PU) films were prepared by mixing star-shaped polyester polyols and crosslinker agent (hexamethylene diisocyanate trimer). The hydrolytic degradation and water absorption experiments demonstrated that the PU films could erode in artificial sea water, which were controlled by varying the ratios of ɛ-caprolactone/trimethylolpropane and the arm number of star-shaped polyester polyols. The mechanical properties of PU films and coatings increased with decreasing the ratios of ɛ-caprolactone/trimethylolpropane and increasing the arm number of star-shaped polyester polyols. The surfaces of PU films and coatings kept eroding, which were revealed by scanning electron microscopy. The copper ion release rates from PU coatings reached steady state at about 31 days. The marine field tests of PU coatings demonstrated that the degradable PU coatings based on star-shaped polyester polyols were effective coatings for marine antifouling.