环氧化端羟基聚丁二烯/甲苯二异氰酸酯型聚氨酯的合成

用环氧化端羟基聚丁二烯(EHTPB)与甲苯二异氰酸酯(TDI)合成了聚氨酯,考察了反应时间、TDI用量、环氧值以及扩链剂1,4-丁二醇(BDO)用量对聚氨酯拉伸性能的影响,通过差示扫描量热法(DSC)分析确定了反应温度,并研究了反应的表现活化能(Ea)和反应级数(n).结果表明,在反应温度为70℃、时间为7 d、-NCO/-OH(摩尔比)为1.4、环氧值为0.001 8 mol/g左右时,聚氨酯的拉伸性能较好;适当加入扩链剂BDO可以同时提高聚氨酯的拉伸强度和扯断伸长率,BDO与EHTPB中-OH的最佳摩尔比为1.0;EHTPB与TDI反应的Ea为59.44 kJ/mol,n为1.02,70℃下的反应速率常数为1.2×10-2s-1     

合成环氧化端羟基聚丁二烯的反应动力学

采用过氧乙酸原位法合成不同环氧值的环氧化端羟基聚丁二烯(EHTPB),从合成EHTPB的基本反应式出发,推导了反应动力学方程,讨论了碳碳双键浓度与反应温度和时间的关系.结果表明,用过氧乙酸对端羟基聚丁二烯进行环氧化改性合成EHTPB的反应为二级反应,其反应速率常数为1.868×10-6dm3/(mol·s),活化能为39.39 kJ/mol,而碳碳双键和过氧化氢的反应则为一级反应.     

环氧丁羟增韧环氧树脂应用研究

采用环氧化端羟基聚丁二烯(EHTPB,简称环氧丁羟)作为环氧树脂固化体系的增韧剂,研究了不同EHTPB质量分数对固化体系力学性能、热性能和电性能的影响。结果表明:随EHTPB质量分数的增加,EHTPB增韧环氧树脂灌封胶的冲击强度呈现先增加后减小的趋势;EHTPB质量分数为10%时增韧环氧树脂灌封胶的冲击强度较佳,增韧性能较好。     

用过氧乙酸原位法合成环氧化端羟基聚丁二烯

用过氧乙酸原位法制备了不同环氧值的环氧化端羟基聚丁二烯,研究了反应温度,反应时间,过氧化氢与端羟基聚丁二烯(HTPB)、冰乙酸与HTPB及磺酸催化剂与HTPB质量比等对产物环氧值、羟值及开环率的影响,并用红外光谱对其结构进行了表征.结果表明,用过氧乙酸原位法可有效控制产物的开环率.最佳环氧化反应条件为反应温度50℃、反应时间7 h、过氧化氢与HTPB质量比2.50、冰乙酸与HTPB质量比0.90、磺酸催化剂与HTPB质量比0.15.     

环氧丁羟环氧值测定方法的研究

研究了在盐酸-四氢呋喃介质中,以酚酞-乙醇作指示剂,氢氧化钠溶液返滴法测定环氧丁羟(EHTPB)的环氧值的方法,考察了反应时间、反应温度、反应介质、指示剂对结果的影响.最终确定了在常温下,EHTPB样品在盐酸-四氢呋喃[V(盐酸):V(四氢呋喃)=1:40]介质中搅拌溶解后静置30 min,以10 g/L酚酞-乙醇作指...     

三臂星形端羟基聚丁二烯的阴离子合成及其表征

以叔丁基二甲基硅氧基丙基锂为引发剂,环己烷为溶剂进行阴离子聚合合成三臂星形端羟基聚丁二烯。采用凝胶渗透色谱(GPC)和1H-NMR方法表征了聚合物相对分子质量及其分布、支化度、平均官能度和主链微观结构。研究结果表明,三臂星形端羟基聚丁二烯的相对分子质量分布指数≤1.1,平均官能度和支化度均接近3。     

Characterization of hydroxyl-terminated polybutadiene

A comparison between the molecular structure of conventional and low molecular weight hydroxyl terminated polybutadienes (HTPBs) is presented. The conventional HTPB samples were R45M, R45HT (Atochem). Liquiflex P and H (Petroflex, Brazil), and the low molecular weight ones were R20LM (Atochem) and two laboratory synthesized materials. The structural differences found were attributed to dissimilarities in fabrication processes for each type of HTPB. Some mechanistic pathways for the polymerization are suggested.     

Characterization of hydroxyl-terminated polybutadiene

¹H and ¹³C NMR spectra were used to study the structure of hydroxyl-terminated polybutadiene (HTPB) obtained by using hydrogen peroxide as initiator and an alcohol as solvent. This alcohol was introduced into the polymer chain, forming a hydroxylated end group. The subject has aroused some argument in the literature and is considered further in our discussion of reaction mechanisms. Received: 29 November 1996/Revised: 4 December 1996/Accepted: 9 December 1996     

Characterization of hydroxyl-terminated polybutadiene

Commercial samples of hydroxyl terminated polybutadienes (HTPB) were analysed by ¹H and ¹³C NMR spectroscopy, in regard to hydroxylated end groups. The results were discussed and compared with those reported so far.     

环氧丁羟增韧双酚A环氧树脂固化反应动力学研究

采用动态差示扫描量热法(DSC)确定环氧丁羟(EHTPB)增韧双酚A环氧树脂固化体系的固化温度,利用Kissinger方程和Crane方程对固化反应动力学进行分析,确定了固化体系的动力学参数:表观活化能ΔE=102.40 k J/mol,指前因子A=1.90×1011,反应级数n=0.93。     

Synthesis of terminally functionalized polyolefines

Summary Propylene-ethylene copolymer (PER), atactic polypropylene (PP) and atactic poly- 4-methyl-1-pentene (P4MP1) were prepared with a Cp₂ZrCl₂-methylaluminoxane catalyst system. These polymers containing terminal vinylidene groups were made to react with halogen, sulfuric acid, 9-borabicyclo [3,3,1] nonane (9-BBN) or percarboxylic acid, leading to terminally halogenated, hydrogen-sulfated, hydroxy-(OH)- or epoxy- functionalized polyolefines. Received: 25 January 2002/ Revised version: 29 March 2002/ Accepted: 29 March 2002     

端羟基聚丁二烯改性醇酸树脂的合成与性能研究

利用梓油和桐油以及带端羟基的聚丁二烯(下文简称丁羟)合成了具有快干特征的醇酸树脂。利用该树脂配制的涂料不仅干性好,且涂层光泽高、鲜映性好,保色保光性优异,可用于农业机械、工程机械等涂装。     

Preparation of epoxidized rubber using a reactive processing technique. I. Synthesis and characterization of epoxidized polybutadiene rubber

The epoxidation of high cis‐butadiene rubbers (BR) with monoperoxy phthalic acid was successfully performed in reactive processing equipment of the HAKKE mixer at room temperature. The effects of such reaction conditions as the concentration of peroxy acid and reaction time on the epoxidation level and the efficiency of monoperoxy phthalic acid were investigated. The structure of epoxidized BR was characterized by ¹H NMR and Fourier transform infrared spectrometer. Differential scanning calorimeter analysis revealed that the glass transition temperature of epoxidized BR had a progressive increase with epoxidation level. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2987–2992, 2001     

负离子聚合法合成端羟基聚丁二烯与自由基法端羟基聚丁二烯的性能对比

以硅烷保护羟基的烷基锂为引发剂,采用负离子聚合法合成了端羟基聚丁二烯(HTPB),通过核磁共振氢谱、傅里叶变换红外光谱、凝胶渗透色谱和差示扫描量热法表征了HTPB的微观结构、分子量分布、官能度及玻璃化转变温度(Tg),研究了HTPB胶片的拉伸性能,并与自由基法HTPB进行了对比。结果表明,负离子法HTPB的1,4-结构摩尔分数约为90%,比自由基法HTPB高约12%,分子量分布小于1.1,低于自由基法HTPB,平均官能度比自由基法HTPB更接近理想值2,Tg为-88.3℃,较自由基法HTPB低9.7℃;负离子法HTPB胶片的拉伸强度与自由基法HTPB胶片相近,但扯断伸长率比自由基法HTPB胶片提高约74%。     

The molecular characteristics of hydroxyl-terminated polybutadiene

Three samples of a commercial hydroxyl-terminated polybutadiene, Arco R45M. were characterised with respect to number-average and weight-average molar mass, intrinsic viscosity, number-average hydroxyl functionality and effective functionality for gelation. Two of the samples were fractionated on the basis of solubility in toluene/methanol mixtures, and the fractions were characterised with respect to number-average molar mass, intrinsic viscosity and number-average hydroxyl functionality. For both sets of fractions, the average functionality was practically independent of average molar mass. It is concluded that the functionality distribution is almost identical at all points in the molar mass range of Arco R45M.     

Functionality distribution and crosslink density of hydroxyl-terminated polybutadiene

A novel approach is proposed for estimating the average molecular weight between crosslinks (M?_c) from the functionality distribution of hydroxyl-terminated polybutadiene ( HTPB ). The functionality distribution of four free-radically polymerised HTPB prepolymers of varying hydroxyl content and molecular weight was determined by a combination of preparative and analytical gel permeation chromatography. The gumstock properties of the samples cured with stoichiometric amounts of toluene diisocyanate were not correlatable with the relative amounts of difunctional chain extender and multifunctional crosslinker present, unlike the case of HTPB with similar hydroxyl content and molecular weight. However, the mechanical properties and sol content could be correlated with the average molecular weight between crosslink sites, M?_c, of the cured polymer. The M?_c values derived by our method compare well with those of classical methods, and the observed differences are attributed to segmental entanglement. These M?_c values give consistently good correlation with all the gumstock properties, confirming the validity of our approach and the soundness of the techniques developed for the determination of the functionality distribution of HTPB .     

端胺基聚丁二烯的合成与表征

采用阴离子聚合法合成了端羟基聚丁二烯,通过端基转化法将羟基转化成胺基,从而合成了端胺基聚丁二烯,通过红外光谱（IR）、核磁共振（1H-NMR）、凝胶渗透色谱（GPC）等对其进行了表征。结果表明,所合成的端胺基聚丁二烯相对分子质量分布较窄（≤1.10）,平均官能度接近2,且微观结构可调;通过羟基值与胺基值的测定表明,端基转化率大于98%。     

端羟基聚丁二烯增韧环氧树脂的性能和微观形貌

以不同数均分子量（珚Mn）的端羟基聚丁二烯（HTPB）为增韧剂,4,4-二氨基二苯甲烷为固化剂,考察了HTPB的珚Mn及用量对环氧树脂的冲击强度、拉伸性能、热稳定性及微观形貌的影响。结果表明,在胺类固化体系中,当HTPB的珚Mn为2 300--3 500且质量分数为1%~3%时,其对环氧树脂具有较佳的增韧效果,且不会对热稳定性产生太大的影响;随着HTPB用量的增加,改性环氧树脂中大尺寸橡胶粒子增多,且HTPB的珚Mn越大,改性环氧树脂中橡胶粒径越大,断裂面由光滑的脆性断裂特性变为粗糙、存在大量应力纹及应力发白区域的韧性断裂特性,再到平滑断裂和大尺度的橡胶颗粒两相分布的低韧性特性。     

端羟基聚异戊二烯及其共聚物的合成与表征

以仲丁基锂为引发剂,引发异戊二烯本体负离子聚合,再用环氧丙烷甲醇终止法合成了端羟基聚异戊二烯;然后利用端羟基聚异戊二烯的活性端羟基,引发丙交酯的开环聚合制备了聚乳酸一聚异戊二烯共聚物,并采用IR、^1H—NMR、TG等测试手段对产品进行了表征。结果表明,通过改变仲丁基锂及环氧丙烷的用量,可合成相对分子质量及羟基含量可控的且1,4-结构质量分数超过87．5％的端羟基聚异戊二烯。     

线型及星形端羟基聚丁二烯的合成与表征

以叔丁基二甲基硅氧基丙基锂为引发剂,丁二烯为单体,环己烷为溶剂,甲基三氯硅烷为偶联剂,采用活性负离子聚合法合成了线型端羟基聚丁二烯(L-HTPB)和星形端羟基聚丁二烯(S-HTPB),并用凝胶渗透色谱和核磁共振氢谱对其结构进行了表征。结果表明,采用该方法合成的2种聚丁二烯,其1,4-结构摩尔分数均接近90.00%,L-HTPB的平均官能度接近2.00,S-HTPB的平均官能度接近3.00,与分子设计值基本相符。