聚氨酯／乙烯基酯树脂互穿聚合物网络合成动力学及相容性

以丙烯酸乙酯为乙烯基酯树脂的共聚单体,利用“同步互穿”工艺室温固化制备了一系列聚氨酯／乙烯基酯树脂互穿聚合物网络 (PU/VER IPN).对IPN固化过程的动态跟踪及半定量考察的结果表明：由于两网络不同的聚合机理及体系黏度的影响,PU网络先形成,网络形成得较完善.采用示差扫描量热仪 (DSC)、原子力显微镜 (AFM)及透射电镜 (TEM)定性考察了IPN两网络间的相容性,结果表明：形成的双相连续“同步互穿”体系的相畴尺寸在纳米级范围,当PU 和VER的组成比为80/20和70/30时体系均出现一个玻璃化转变温度 (T_g),较好地改善了PU与常规VER树脂的相容性.进一步通过DSC实测和理论T_g值的计算获得相容因子 (θ),定量考察了两网络间的相容性.     

宽温域高阻尼互穿聚合物网络材料的结构与性能

以环氧丙烯酸酯和甲基丙烯酸丁酯(二者质量比为2/1)混合物为乙烯基酯树脂(VER)。1,4-丁二醇为扩链荆,采用“同步互穿”工艺,室温下与聚氨酯(PU)预聚物固化制备了低温至室温区阻尼温域近70℃、损耗因子(tanδ)大于0．4的PU/VER互穿聚合物网络(IPN)。结果表明,当PU/VER(质量比,下同)为70/30时,IPN的tanδ大于0.7的阻尼温域近40℃。采用傅里叶变换红外光谱仪及原子力显微镜考察了试样的连续相构成及微观结构表明,形成的双相连续“同步互穿”体系的相畴尺寸在纳米级范围,组成比为70/30的IPN较50/50者相容性好。力学性能测试结果表明,随VER用量的增加．试样具有由弹性到脆性的形变规律。     

汽车风挡玻璃用密封胶的结构与性能研究

研究了三种汽车风挡玻璃用单组分PU(聚氨酯)密封胶和SPU(硅烷改性聚氨酯)密封胶。采用红外光谱(FT-IR)、凝胶渗透色谱(GPC)法分析了三种密封胶的结构和相对分子质量,并对其固化行为、粘接性能和力学性能等进行了研究。结果表明:相对湿度越大(或固化温度越高),则三种密封胶的表干时间越短且固化速率越大;在三种密封胶的储存过程中,其表干时间和固化速率变化不大,稳定性较好;SPU密封胶与基材的粘接性能优于PU密封胶;PU密封胶的拉伸强度(≥8.2 MPa)和撕裂强度(19 N/mm)均优于SPU密封胶的拉伸强度(5.8 MPa)和撕裂强度(13 N/mm)。     

受阻酚改性PU/PBMA IPN材料阻尼性能的研究

以聚碳酸酯二醇(PC-2000)、二苯甲烷二异氰酸酯(MDI)为原料合成聚氨酯(PU)预聚体,再以PU预聚体、扩链剂、甲基丙烯酸丁酯(BMA)及引发剂在一定条件下反应制备了聚氨酯/聚甲基丙烯酸正丁酯(PU/PBMA)互穿网络聚合物(IPN)材料,并加入受阻酚AO-80进行功能化改性,分别采用热固化法和室温固化法制备了受阻酚AO-80改性的PU/PBMA IPN材料。讨论了固化方法、PU与PBMA的配比、受阻酚AO-80用量等对IPN材料阻尼性能的影响,通过动态机械热分析、热失重分析以及扫描电子显微镜对IPN材料的阻尼性能、热稳定性和微观形态结构进行表征。结果表明,热固法比室温固化法更有利于制备高性能阻尼材料;受阻酚AO-80的加入可以明显提高IPN材料的阻尼性能,并能够有效地拓宽阻尼温域;当PU与PBMA质量比为60/40、AO-80质量分数为28%时,所制备的IPN材料的阻尼性能最佳。     

固化动力学对PU/VER同步互穿网络聚合物性能的影响

互穿网络聚合物(IPNs)是一种特殊的交联聚合物合金.本研究以聚氨酯(PU)和乙烯基酯(VER)预聚物为原料,在室温下合成了互穿网络聚合物.采用傅立叶红外光谱法跟踪了网络形成的动力学过程并进行半定量分析,研究了固化体系对互穿纲络聚合物的摩擦学性能、力学性能及光学性能等的影响.结果显示,两种预聚物在固化过程中虽遵循不同的聚合机理,却相互影响制约.通过改变引发剂和催化剂的配比得到的样品显示出不同特性.当VER引发剂的用量为0.75%,PU催化剂的用量为0.6%时,两网络可基本实现同步互穿;同步互穿网络聚合物显示出良好的耐磨性,在实验条件下涂层寿命可达28.81 min,且力学性能优异,在可见光波长范围内具有良好的透光性, 450 nm处的透光率可达85%.     

2003年中国聚氨酯研究与应用论文题录(六)

PU/VER IPN材料阻尼性能的研究/秦川丽,蔡俊,唐冬雁 等(哈尔滨工业大学)//材料工程一2003,(7)一36~39转 42 聚氨醋一丙烯酸醋乳液的制备与性能/蒋欣,刘治猛,刘煌平 等(东莞理工学院高分子材料与环境工程研究中心)//石油 化工一2003,32(7)一604一607 聚氨酉拿环氧树脂互穿网络硬     

端羟基液体丁腈橡胶对聚氨酯泡沫塑料性能的影响

采用一步法制备聚氨酯硬质泡沫塑料(RPUF)。考察了端羟基液体丁腈橡胶(HTBN)对聚氨酯硬质泡沫塑料表观密度、吸水性能、力学性能等的影响。结果表明:随着HTBN含量的增加,硬泡PU制品的密度逐渐降低,压缩强度、弯曲强度呈降低趋势,吸水率增加。     

聚氨酯预聚体接枝环氧树脂的制备及固化性能研究

采用分步法合成了聚氨酯(PU)预聚体/环氧树脂(E-51)接枝共聚物(g-PU/EP),以自制二聚酸聚酰胺为固化剂,对固化体系的固化性能进行了研究。结果说明:当PU预聚体/E-51质量比为20∶100时,固化体系的剪切强度(铝-铝)最大为14.1 MPa;SEM分析结果表明,接枝后固化物呈典型韧性断裂;TG分析表明,接枝改性对固化物耐热性的影响较小。     

聚氨酯预聚体接枝环氧树脂的制备及固化性能研究

采用分步法合成了聚氨酯(PU)预聚体/环氧树脂(E-51)接枝共聚物(g-PU/EP),以自制二聚酸聚酰胺为固化剂,对固化体系的固化性能进行了研究。结果说明:当PU预聚体/E-51质量比为20∶100时,固化体系的剪切强度(铝-铝)最大为14.1 MPa;SEM分析结果表明,接枝后固化物呈典型韧性断裂;TG分析表明,接枝改性对固化物耐热性的影响较小。     

耐高温环氧树脂增韧体系的研究

使用双酚A型环氧乙烯基酯树脂(VER)与双酚F型环氧树脂(EP)同步固化的方法，对环氧树脂进行增韧；采用DSC研究了混合体系的固化反应过程，对固化材料的力学性能和热机械性能进行了测试，并用扫描电子显微镜(SEM)表征其形态结构。结果表明，当m(VER)：m(EP)=90：10时，固化材料的的玻璃化转变温度达到207．3℃，分别比纯环氧树脂和纯VER树脂高25℃和75℃；当m(VER)：m(EP)=50：50时，材料的冲击强度达到了8．08kJ／m2，体系具有最好的综合机械性能和较好的耐热性。     

聚氨酯／乙烯基酯树脂互穿聚合物网络的力学性能研究

研究了适用于反应注射成型的乙烯基酯树脂（ＶＥＲ）与聚氨酯（ＰＵ）形成互穿聚合物网络（ＩＰＶ）时，ＶＥＲ中的羟基与异氰酸酯的反应对材料力学性能的影响。实验结果表明，若异氰酸酯的化学计量忽略ＶＥＲ中的羟基，则对所合成的ＰＵ／ＶＥＲＩＰＮ而言，ＰＵ对ＶＥＲ的增韧效果较差；若异氰酸酯的用量考虑ＶＥＲ中的羟基含量，则用碳化二亚胺改性二苯基甲烷二异氰酸合成的ＰＵ／ＶＥＲ（组成比５０／５０）ＩＰＮ的拉伸或冲击强度分别比纯ｐｕ或纯ＶＥＲ网络要高得多，可获得兼具刚性与韧性的材料。在这类ＩＰＮ中添加少量聚醚接枝的ＶＥＲ，可有效地提高材料的拉伸强度。     

聚氨酯/乙烯基酯树脂互穿聚合物网络结构与性能的研究

通过同步法制备了一系列聚氨酯／乙烯基酯树脂互穿聚合物（ＰＵ／ＶＥＲ－ＩＰＮ）,研究了ＰＵ／ＶＥＲＩＰＮ性能的影响因素。结果表明：随着ＰＵ含量的增加,ＩＰＮ的热稳定性能有一定程度的提高;而ＶＥＲ的含量增加,ＰＵ／ＶＥＲ－ＩＰＮ的剪切强度提高。实验还发现：当ＰＵ／ＶＥＲ－ＩＰＮ为部分相容的多相微区结构时,对增加ＩＰＮ的力学损耗更有利     

聚氨酯/环氧树脂互穿网络聚合物硬质泡沫机械性能研究

采用同步法合成了聚氨酯/环氧树脂互穿网络聚合物(PU/EP IPN)硬质泡沫,对机械性能进行了研究。结果表明,与纯聚氨酯硬质泡沫相比,PU/EP IPN硬质泡沫的压缩强度和弯曲强度明显提高,在PU/EP IPN硬质泡沫中,随环氧树脂含量增加,PU/EP IPN硬质泡沫压缩强度和弯曲强度随之增大,当E-39D质量分数增加到24.2%时,PU/EP IPN硬质泡沫压缩强度和弯曲强度出现最大值;PU/EP IPN硬质泡沫机械强度随材料密度的增大而增加;随着环氧树脂中环氧值的增加,PU/EP IPN硬质泡沫的压缩强度、弯曲强度和拉伸强度均呈逐渐升高的趋势。     

Acoustical,damping and thermal properties of polyurethane/poly(methyl methacrylate)-based semi-interpenetrating polymer network foams

In the present study, the interpenetrated polymer networks (IPN) foams of polyurethane (PU) and poly(methyl methacrylate) (PMMA) with different ratio of PU/PMMA (i.e. 85/15, 75/25 and 65/35) were prepared using the polymerisation process. The acoustical, damping and thermal properties of synthesised IPN foams with regard to different compositions were studied. As indicators of effective damping capability, viscoelastic parameters including loss factor (tan δ), glass transition temperature (T_g) and effective damping interval (tan δ?>?0.3) were also determined. The results show that the T_g shifted to higher temperature ranges, and the damping temperature range (tan δ?>?0.3) increased when the IPN was formed. The sound absorption coefficient results show that because of the formation of IPN, the sound-absorbing capacity of prepared samples increased at a certain frequency, and the resonance frequency shifted to lower frequencies by increasing the PMMA content in IPN foams.     

网络间的化学键效应对聚氨酯／乙烯基酯树脂IPN形态与力学性能的影响

本文通过环氧树脂（Ｅ—５１）与甲基丙烯酸合成了大分子链中含有羟基或羟基被封闭的乙烯基酯树脂（分别称为ＶＥＲＨ与ＶＥＲＡ），并用它们与聚氨酯（ＰＵ）合成了不同组成的ＰＵ／ＶＥＲ互穿网络（ＩＰＮ），用扫描电子显微镜考察了这些ＩＰＮ材料的形态，发现网络间的化学键对ＩＰＮ的形态有很大影响，它们抑制了两个网络间的分相以及ＰＵ硬段局部有序结构的形成。对这些材料的力学性能进行了测定，结果表明网络间的化学键能较大幅度地提高材料的力学性能。     

Structure and properties of semiinterpenetrating polymer networks based on polyurethane and nitrochitosan

Two semiinterpenetrating polymer networks (semi‐IPNs) based on trihydroxyl methylpropane–polyurethane (T‐PU) or castor oil–polyurethane (C‐PU) were prepared by curing the mixed solution of the polyurethane prepolymer and nitrochitosan (NCH). During the curing process, crosslinking and grafting reaction between the molecules of the PU prepolymer and NCH occurred, because of the high reactivity of remaining hydroxyl groups in the NCH with ? NCO groups of PU. The structure of the original semi‐IPN sheets and the sheets treated with acetone were studied by infrared, ¹³C‐NMR, scanning electron microscopy, and dynamic mechanical analysis, showing interpenetration of NCH molecules into the PU networks. When nitrochitosan content (C_NCH) was lower than 10 wt %, the semi‐IPN sheets T‐PU and C‐PU had higher density and tensile strength (σ_b) than the systems with C_NCH more than 20%. The trihydroxymethyl propane‐based PU reacted more readily with nitrochitosan to form the semi‐IPNs than castor oil‐based PU. The semi‐IPN coatings T‐PU and C‐PU were used to coat cellophane, resulting in intimate interfacial bonding. The mechanical strength and water resistivity of the cellophane coated with T‐PU coating were improved remarkably. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3109–3117, 2001     

双丙酮丙烯酰胺在固体推进剂粘合体系中的应用

用互穿聚合物网络技术(IPN),将双丙酮丙烯酰胺(DAAM)用于PU粘合剂的改性,考察了固化参数、组分比、引发剂用量对PDAAM/PU互穿网络体系力学性能及微观形态的影响。结果表明,PDAAM质量分数为40%,固化参数为1.4,引发剂过氧化苯甲酰(BPO)的质量分数在0.8%~1%时,拉伸强度最高可达1.028 MPa,比相同条件下制备的纯PU的拉伸强度(0.238 MPa)提高了332%;断裂伸长率达到327.35%,比相同条件下制备的纯PU的断裂伸长率(49.02%)提高了568%。组成比、固化催化剂、引发剂用量对PDAAM/PU IPN的微观形态也有影响。PDAAM质量分数较大时,两相界面模糊,互穿较好。三苯基铋(TPB)作为固化催化剂或塑料相的引发剂浓度较低,两相反应速度相近时,相畴较小。     

Static and dynamic mechanical properties of modified bismaleimide and cyanate ester interpenetrating polymer networks

Interpenetrating polymer networks (IPNs) based on different ratios of modified bismaleimide (BMI) resin [BMI/2,2′‐diallylbisphenol A (DBA)] and cyanate ester (CE) (b10) have been synthesized via prepolymerization followed by thermal curing. A systematic study of both static and dynamic mechanical properties of the cured BMI/DBA–CE IPN resin systems was conducted through flexural, impact testing, and dynamic mechanical analysis (DMA). The static mechanical investigation shows that the flexural strength, flexural strain at break, and impact strength of the cured BMI/DBA–CE IPN resin systems are relatively lower than that calculated by rule of mixture of two individuals: BMI/DBA and b10. However, the flexural moduli of the IPN resin systems have more consistent features compared to that calculated by rule of mixture. Single damping peaks are detected for the cured BMI/DBA–CE IPN resin systems, which suggests a substantial degree of interpenetration between two networks. The damping peaks of the cured BMI/DBA–CE IPN resin systems do tend to become broader with increasing concentration of BMI/DBA, whereas the intensity of damping peaks of the IPN resin systems decreases. The obtained results not only provide insight information about the characteristic structures of these BMI/DBA‐–CE IPN resin systems, but also give guidelines for their applications. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2000–2006, 2003     

High internal phase emulsion foams: Copolymers and interpenetrating polymer networks

High internal phase emulsion (HIPE) copolymer and interpenetrating network foams were prepared from 2‐ethylhexyl acrylate (EHA), styrene (S) and divinylbenzene (DVB) using a unique process. The morphologies, thermal properties and dynamic and static mechanical properties of these foams were investigated. The glass transition temperatures and damping properties of the EHA/S copolymer foams vary with its composition. IPN foams with very broad tan 5 peaks were obtained. The damping properties of IPN foams were tailored through changing copolymer composition and monomer composition. The IPN foams based on a copolymer foam and styrene had a broader tan δ peak, a higher glass transition temperature and a higher modulus than tne copolymer foams of similar overall styrene contents. It is therefore possible to prepare novel damping foams based on polyHIPE foams through the synthesis of interpenetrating polymer networks.