一种含有乙烯基具有固-固相变性能的大单体的制备及表征EI

通过分子设计,把具有固-液相变性能的聚乙二醇单甲醚(MPEG)的端羟基改性为具有乙烯基碳碳双键的大单体,形成一种可以与任意含有乙烯基双键的骨架材料进行自由基共聚合的具有高相变焓的固-固相转变单体材料。运用傅立叶变换红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)表征了大单体的结构,采用差示扫描量热法(DSC)、广角X射线散射仪(WAXD)和偏光显微镜(POM)、热失重(TG)表征并分析了MPEG的热性能及其结晶情况。结果表明,这种新型单体具有稳定的分子结构、良好的结晶性能、高相变焓,热稳定性良好。从而为聚乙二醇类的固-液相变材料在固-固相变材料的应用领域中开辟了一条新的途径。     

壳聚糖-g-硬脂酸固-固相变材料制备与表征

采用化学接枝的方法将具有固-液相变性能的硬脂酸接枝到壳聚糖高分子链上,制得一种具有固-固相变性能的新型高分子相变材料:壳聚糖-g-硬脂酸固-固相变材料,并采用傅里叶变换红外光谱(FT-IR)、差示扫描量热仪(DSC)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、偏光热台显微镜(POM)和热失重分析仪(TG)等对接枝产物进行了表征。结果表明,硬脂酸通过化学键连接在壳聚糖分子链上;壳聚糖-g-硬脂酸固-固相变材料呈现出可逆的固-固相转变特性,且具有与硬脂酸相似的结晶结构,吸热焓值为21.33J/g(相变温度为60.5℃),放热焓值为14.03J/g(相变温度为47.11℃),具有良好的热稳定性,热失重拐点温度为233.11℃。     

一种添加蛋白石的固-固相变储能材料的制备及表征

利用天然纳米材料蛋白石(Opal)制备出新型有机-无机体系的聚氨酯/Opal固-固相变储能材料,并通过IR1、H-NMR、DSC、TG、POM、TEM等测试手段对其结构和性能进行表征分析。结果表明,该聚氨酯型相变材料具有较高的相变焓值、适宜的相变温度、热性能稳定和相变过程中不产生液体等特点。同时,加入天然纳米无机材料蛋白石后,结晶性能得到提高。     

聚乙二醇基复合相变材料的制备与热性能研究

利用聚乙二醇(PEG)为相变材料、以羟丙基甲基纤维素为分子骨架,采用4,4-二苯基甲烷二异氰酸酯作为交联剂,用化学接枝法成功合成了一种新型复合相变材料。采用红外光谱、差示扫描量热仪、热重仪、扫描电镜和X射线衍射仪对该复合相变材料的化学结构、相变性能、热稳定性、微观形貌和晶体结构等性能进行了表征。结果表明:该复合相变材料的相变过程表现为固-固相变的性质,其相变温度在309~323.2K范围内,相变焓值在89.8~106.8J/g之间。可见,通过化学接枝法得到的复合相变材料具有较好的相变行为,且克服了聚乙二醇在相变过程中的泄露问题。     

一种MGPM/Opal固-固相变储能材料的相变及结晶行为

采用含有相变单元的单体缩聚法合成了侧链含有聚乙二醇单甲醚（MPEG）的新型固-固相变储能复合材料（相变共聚物缩写名称为（MGPM）/蛋白石（opal））,通过广角X射线衍射（WAXD）、差热扫描量热仪（DSC）和热台偏光显微镜（POM）、热重（TG）等测试手段对其结晶结构、结晶行为、结晶形态和热稳定性进行了研究,结果表...     

聚乙二醇/不饱和聚酯树脂复合相变储热材料的性能

以聚乙二醇(PEG)为相变材料,不饱和聚酯树脂(UPR)为定形载体,采用熔融共混法制备PEG/UPR定形相变材料(PEG/UPR SS-PCMs)。运用差示扫描量热分析、热重分析、X射线衍射、红外光谱手段分别对SS-PCMs的热性能、热稳定性、化学结构、SS-PCMs中各个组分之间的物理化学作用、结晶性能等进行表征。结果表明,SS-PCMs中PEG的端羟基与UPR或其固化物中的C=C双键、端羟基或端羧基分别发生加成反应及分子间脱水反应,生成醚或酯,两者之间的化学作用力较强,束缚着PEG的自由运动,呈现出不同于自由态下的固-固相变行为,故不同PEG掺量的SS-PCMs的相变温度(60℃左右)均较纯PEG的高,相变焓(80.1~133.7 J/g)较理论相变焓低9.1%~17.4%;PEG中间链节为能够自由运动的醚基,且端羟基比例小,故SS-PCMs中PEG链段大部分能够结晶且发挥相变行为,结晶性能稳定;SS-PCMs在温度低于382.6℃时,无热降解现象,热稳定性好。     

形态稳定相变材料聚乙二醇/聚酰胺6共混物的制备及性能

以聚醚酯酰胺(PEEA)为相容剂,以溶液共混的方法制备了形态稳定的聚乙二醇(PEG)/聚酰胺6(PA6)相变材料,对材料的形态结构、固-固相变、热性能及相变实质进行了研究。结果表明,制备形态稳定的相变材料(PCM),PEG的最大添加量为80%(质量分数);材料的相变温度及相变焓随PEG质量分数的增加和分子质量的增大而提高;材料在相变温度下发生了固-固相转变,其实质是PEG在相变温度下由结晶态到无定型态的相互转变,材料在循环加热的条件下也能一直保持稳定的形态,无熔化泄漏。     

基于聚丙烯腈和聚乙二醇的侧链型相变材料的制备及表征

以不同分子量聚乙二醇(PEG)、4,4’-二苯基甲烷二异氰酸酯(MDI)、甲基丙烯酸羟乙酯(HEMA)、丙烯腈(AN)为主要原料,采用两步法先合成大分子单体(HMPEG),然后利用水相沉淀法,将大分子单体与丙烯腈(AN)以及第三单体甲基丙烯酸甲酯(MMA)接枝共聚,形成一种以丙烯腈和甲基丙酸甲酯聚合物P(AN-coMMA)为主链,大单体(HMPEG)为侧链的系列接枝型相变材料P(AN-co-MMA)-g-HEPEG。通过傅里叶变换红外光谱(FT-IR)、差示扫描量热(DSC)、热重(TG)和X射线衍射(XRD)对大单体和共聚物的结构、相变行为、热稳定性和晶体结构进行了研究。结果表明,合成的大分子单体及其共聚物是一系列具有稳定的结构、良好的结晶性能、高相变焓及良好热稳定性的相变材料。当PEG分子量为4 000时(m(HMPEG)∶m(AN)=45∶45),接枝型相变材料P(AN-co-MMA)-g-HMPEG4000的熔融峰温度为52℃,结晶峰温度为26℃,热焓为31J/g,在290℃以下热稳定性良好,可用于加工或使用温度较高的环境。     

聚乙二醇/聚丙烯腈共混物的增容机理和蓄热储能性

以丙烯腈(AN)和衣康酸(IA)共聚生成丙烯腈/衣康酸共聚物(P(AN-co-IA))为相容剂,用溶液共混法制备聚丙烯腈/聚乙二醇高分子固-固相变材料,用傅里叶变换红外光谱(FT-IR)、步冷曲线、差热分析(DSC)、X射线衍射(XRD)及偏光显微镜等手段对共混物进行表征,分析讨论了P(AN-co-IA)的增容机理和蓄热储能性。结果表明,P(AN-co-IA)对聚乙二醇/聚丙烯腈(PAN/PEG)共混体系具有良好的增容效果,共混材料的保温性能良好,具有较大的焓值,其相变温度和相变焓随着PEG含量的增加而提高,共混物呈现出"固-固"相变特性。在有限次的循环加热中相变温度及相变焓无明显变化,表明材料的蓄热耐久性良好。     

聚乙二醇基固-固相变材料的制备及其在加热卷烟中的降温效果研究

为解决加热卷烟入口烟气温度过高的问题，采用接枝共聚的方式合成了聚乙二醇基固-固相变材料，研究了反应条件对接枝产物相变行为的影响，并考察了接枝产物对加热卷烟入口烟气温度和关键成分释放量的影响。结果表明：采用接枝共聚合成的醋酸纤维素接枝聚乙二醇单甲醚共聚物(CA-g-mPEG)表现为固-固相变行为，并且具有优异的热稳定性。相变工作单元mPEG的分子量与接枝率对CA-g-mPEG的相变行为有直接影响，优选的CA-g-mPEG₅₀₀₀的相变温度为58.9℃,相变焓为150.2J/g。与IQOS以及未涂覆降温材料的加热卷烟相比，采用涂覆CA-g-mPEG₅₀₀₀降温滤棒的加热卷烟的最高入口烟气温度分别降低9.5℃、11.6℃,说明CA-g-mPEG₅₀₀₀具有优异的烟气降温效果。相对于未涂覆降温材料的加热卷烟，添加CA-g-mPEG后加热卷烟主流烟气的总粒相物、烟碱、丙二醇、丙三醇、水分含量有所降低。     

多官能度松香聚合单体的微波辅助合成与UV光固化性能

松香的菲环骨架结构能够赋予聚合材料优良的热稳性和柔韧性,将松香中特定树脂酸结构直接合成高纯度聚合单体是解决这一问题的有效途径。在前期研究基础上,文中进一步开发了具有三官能度的马来海松酸三烯丙酯聚合单体,首先将松香树脂酸进行Diels-Alder反应得到马来海松酸酐,并经过中和反应得到马来海松酸钠。在微波辅助下,马来海松酸钠与烯丙基氯在相转移催化剂作用下制备得到GC纯度为96.1%的聚合单体——马来海松酸三烯丙酯。反应产物的结构通过红外光谱、气相色谱-质谱联用技术、核磁共振、元素分析等技术表征。UV固化反应的结果表明,具有3种活性官能团的马来海松酸聚合单体有很强的聚合活性,所得聚合物具有较好的热稳定性,分解温度达到300℃,玻璃化转变温度为49.57℃。     

氧化降解程度对接枝共聚改性淀粉性能的影响

以玉米淀粉为原料,(NH4)2S2O8为氧化剂,采用一步氧化法对淀粉氧化降解,进而与乙烯基类单体接枝共聚,制备了乙烯基类单体接枝共聚改性淀粉,并应用于蓝湿革复鞣工艺。结果表明,当(NH4)2S2O8用量为7.5%、降解温度为95℃、降解时间为30min时,共聚物的接枝率、接枝效率和单体转化率较高,且共聚物对坯革具有一定的复鞣填充和捕获游离甲醛的作用。FT-IR、XRD和TGA结果表明乙烯基类单体已成功接枝于氧化降解淀粉分子上。     

Biodegradation of poly(vinylalcohol-co-ethylene) with the fungus phanerochaete chrysosporium

Under appropriate conditions for lignine peroxidase production in a culture medium that contains spores of Phanerochaete Chrysosporium fungus, the biodegradation of ethylene vinyl alcohol (EVOH) pellets with 27% mole of ethylene content was observed after 30 days. The oxidative degradation was detected by Fourier Transform Infrared Spectroscopy (FTIR) through the formation of hydroperoxides containing chains which were broken with degradation time. Differential Scanning Calorimetry (DSC) initially showed only one melting peak and after 30 days two peaks appeared on the thermogram, one due to the remaining copolymer that did not change with degradation time and the other due to the polymer degradation sequence. When EVOH film with a similar amount of ethylene was used, the initial melting temperature (T_m) decreased during degradation and a second crystalline sequence with a lower T_m was produced, indicating that both copolymer sequences were degraded. Observed differences in the biodegradative behavior between EVOH pellets and EVOH film were mainly due to the changes in crystallinity of the copolymer induced by film processing. The initial EVOH film showed a lower crystallinity and the presence of double bonds, which favors the degradative process. Received: 18 September 2000 / Reviewed and accepted: 20 September 2000     

VAc-BA乳液共聚实验及Monte Carlo模拟

改变加料速率作了４组ＶＡｃ－ＢＡ半连续乳液共聚的实验，测定了动力学并建立了简化的动力学模型，用ＭｏｎｔｅＣａｒｌｏ方法模拟了反应过程中共聚物链段组成的分布，模拟了同种单体的最长链段长度，它可惟作为微观相分离程度，微区尺寸大小的判据，模拟结果和文献报道进行了对照，对玻璃化温度这一聚合物溶混性的判断标准进行了补充和说明。     

丙烯酸2-乙基己酯与醋酸乙烯酯共聚合成高吸油性树脂的研究

以丙烯酸2－乙基己酯与醋酸乙烯酯为单体，采用悬浮聚合法，以单体自交联制得高吸油性树脂。对影响其吸油性能的多种因素，如单体配比、引发剂、油水相比的用量等，进行了系统的研究，得到的高吸油性树脂吸苯最高达16．1g/g，吸甲苯为14．8g/g，吸环己烷为13．3g/g，吸煤油为12．5g/g，可用于河面、海洋浮油的回收及工厂废水处理等领域.     

Quality improvement of paper‐sheets by radiation‐induced graftcopolymerization of vinyl monomers onto paper‐cellulose

Abstract

Gamma radiation‐induced graftcopolymerization of serveral vinyl monomers onto paper‐cellulose has been investigated by using four kinds of domestic paper‐sheets. Among the vinyl monomers the ethyleneglycol dimethacrylate‐acryl amide (EGDMA‐A.Amide) system was found to give the best flexibility and the strongest tensile‐strength.

The in situ copolymerization‐rate and the grafting‐rate of the monomer system of EGDMA‐A.Amide were found to be proportional to the 0.46th power and 1.0–1.2th power of the gamma does‐rate respectively. The grafted copolymer‐chains of the EGDMA‐A.Amide System were confirmed by the infrared absorption spectra in which the characteristic absorption bonds of 5.8μ (ester group) and 6.06μ (amide group) were displayed.

The tensile strength of the EGDMA—A.Amide copolymer grafted papers prepared through the gamma dose up to 1.29 Mrad was found to be 1–2.83 times (dry state) and 1.16–3 times (wet state) the sizes of the corresponding original papers under the same state of testing.     

氯乙烯与硅氧烷类单体共聚树脂的研究

详细叙述了氯乙烯与硅氧烷类单体的聚合工艺和配方 ,并指出了硅氧烷类单体的选择范围。提供了共聚物氧气透过性的测试方法。     

Graft copolymers of propylene with styrene and methylmethacrylate: Structure,crystallization and thermal behaviour

Nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), wide and small angle X-ray scattering (WAXS and SAXS) investigation have been used in order to achieve a molecular, thermal and structural characterization of a sample of propylene-butadiene copolymer containing 3% (wt/wt) of butadiene (uPP) and of uPP samples modified by grafting polymethylmethacrylate (upp-g-PMMA) and polystyrene (uPP-g-PS). The uPP copolymer was synthesized by Himont according to method patented by Himont [1], that allows, by means of the use of a proper catalyst system, co-polymers of propylene with diene having conjugated double bonds in which at least 20% of the unsaturations is of the vinyl type to be obtained. The influence of concentration, distribution and type of the uncrystallizable comonomer units on the thermal behaviour of such co-polymers and on the kinetic, morphologic and thermodynamic parameters related to crystallization process from melt have been also investigated.     

MMA/MPEOMA/VSA copolymer as a novel blood-compatible material: ex vivo platelet adhesion study

MMA/MPEOMA/VSA copolymers with both pendant polyethylene oxide (PEO) side chains and negatively chargeable side groups were synthesized by random copolymerization of methyl methacrylate (MMA), methoxy PEO monomethacrylate (MPEOMA; PEO mol. wt, 1000), and vinyl sulfonic acid sodium salt (VSA) monomers with different monomer composition to evaluate their blood compatibility. MMA/MPEOMA copolymer (with PEO side chains) and MMA/VSA copolymer (with negatively chargeable side groups) were also synthesized for the comparison purpose. The synthesized copolymers were coated onto polyurethane (PU) tubes (inner diameter, 4.6 mm) by a spin coating. The platelet adhesion of the MMA/MPEOMA/VSA copolymer-coated tube surfaces was compared with that of tube surface coated with MMA/MPEOMA or MMA/VSA copolymer with similar MPEOMA or VSA composition, using an ex vivo canine arterio-artery shunt method. The platelet adhesion was evaluated by radioactivity counting of technetium (99mTc)-labeled platelets adhered on the surfaces after 30 and 120 min of blood circulation. The MMA/MPEOMA/VSA copolymer (monomer molar ratio 9/0.5/0.5 or 8/1/1) was better in preventing platelet adhesion on the surface than the MMA/MPEOMA or MMA/VSA copolymer with similar MPEOMA or VSA composition, probably owing to the combined effects of highly mobile, hydrophilic PEO side chains and negatively charged VSA side groups.