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2,2-二(溴甲基)-1,3-丙二醇的合成 总被引:4,自引:0,他引:4
以季戊四醇和40%氢溴酸溶液为原料,冰醋酸为催化剂,经取代反应、减压分离、纯化和干燥等步骤合成了具有优良性能的反应型阻燃剂2,2 二(溴甲基) 1,3 丙二醇,以季戊四醇计,产品收率为80.8%。实验确定了氢溴酸与季戊四醇的最佳摩尔比为2.5∶1,最佳反应时间为6~8h,最佳反应温度为回流温度。先用等体积的甲苯和水混合物分离合成产物,再用热水重结晶进行纯化。经元素分析、熔点测定和红外光谱分析予以确证。 相似文献
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以对苯二甲酸(PTA)、乙二醇(EG)和1,4-环己烷二甲醇(CHDM)作为原料,经过酯化缩聚制备聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)。研究CHDM质量含量(0~20%)对PETG共聚酯酯化和缩聚过程的影响,同时利用热失重分析(TGA)、差示扫描量热仪(DSC)等对PETG共聚酯的常规性能、热性能进行分析。结果表明,在等负荷和相同原料醇酸比的条件下,随着CHDM添加量的增加,酯化水馏出量逐渐下降,但酯化速率变化不大;共聚酯的缩聚反应速率在聚合后期呈下降趋势;随着CHDM添加量的增加,二甘醇的含量逐渐减少,玻璃化转变温度上升,熔点降低;氮气氛围下,聚酯的失重量逐渐增大,表明PETG的热稳定性逐渐降低。 相似文献
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《应用化工》2022,(11)
通过共沉淀法制备Ti-Mg复合催化剂,用于合成聚对苯二甲酸1,3-丙二醇酯(PTT)。考察了催化剂焙烧温度、催化剂用量及反应条件对合成PTT产品的影响。结果表明,经550℃焙烧的Ti-Mg复合催化剂具有良好的催化活性,在反应条件:催化剂用量为550 mg/L(基于对苯二甲酸的质量),酯化温度235℃,酯化时间180 min,缩聚反应温度260℃,缩聚时间140 min,磷酸三苯酯用量为150 mg/L(基于对苯二甲酸的质量)时,合成的PTT产品的特性粘度达到0.913 8 dL/g,b值为2.38,端羧基含量为17.24 mmol/kg。分别采用XRD和SEM表征催化剂,发现催化剂表面呈现光滑且规整的六角棒状结构。 相似文献
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《应用化工》2019,(11)
通过共沉淀法制备Ti-Mg复合催化剂,用于合成聚对苯二甲酸1,3-丙二醇酯(PTT)。考察了催化剂焙烧温度、催化剂用量及反应条件对合成PTT产品的影响。结果表明,经550℃焙烧的Ti-Mg复合催化剂具有良好的催化活性,在反应条件:催化剂用量为550 mg/L(基于对苯二甲酸的质量),酯化温度235℃,酯化时间180 min,缩聚反应温度260℃,缩聚时间140 min,磷酸三苯酯用量为150 mg/L(基于对苯二甲酸的质量)时,合成的PTT产品的特性粘度达到0.913 8 dL/g,b值为2.38,端羧基含量为17.24 mmol/kg。分别采用XRD和SEM表征催化剂,发现催化剂表面呈现光滑且规整的六角棒状结构。 相似文献
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研究了不同异山梨醇(ISB)含量的聚(对苯二甲酸乙二醇酯-co-对苯二甲酸异山梨醇酯)(PEIT)共聚酯预结晶及固相聚合工艺。探讨了温度、时间与PEIT共聚酯预结晶温度、固相聚合反应速率之间的关系;利用差式扫描量热仪(DSC)分析研究PEIT共聚固相聚合前后的热性能变化情况。结果表明:随着ISB用量的增加,PEIT共聚酯结晶困难,预结晶时间增加,固相聚合反应速率减慢;随着温度升高,PEIT共聚酯固相聚合反应速率加快,但仍慢于聚对苯二甲酸乙二醇酯(PET);固相增粘后PEIT共聚酯玻璃化转变温度(Tg)与ISB含量呈线性上升关系。 相似文献
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以自制的1,3-丙二醇钛为催化剂,采用对苯二甲酸(PTA)和1,3-丙二醇(PDO)为原料,通过直接酯化法制得聚对苯二甲酸丙二醇酯(PTT);研究了催化剂用量、反应物配比、酯化和缩聚温度、缩聚时间等对反应结果的影响.结果表明:以1,3-丙二醇钛为催化剂制备PTT是可行的;在酯化反应温度为230~235℃,PDO/PTA... 相似文献
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Summary A thermotropic liquid crystal copolyester (CHQ/BP/TA/IA; 40/10/40/10) (LCP), and melt blends of poly (ethylene terephthalate) (PET) with LCP have been studied for thermal transition and crystallization behaviour. The LCP has a mesophase transition (KM) in the temperature range of 295–315°C. The endothermic peak showing mesophase to Isotropic (MI) transition is observed around 420°C. These transitions are supported by hot stage polarizing microscopy. In blends of PET/LCP, the mesomorphic transition is observed at temperature around 314°C, along with the melting transition of PET around 274°C. The dynamic calorimetric measurements reveal that the two polymers are at least partially miscible. 相似文献
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A series of co[poly(ethylene terephthalate-p-oxybenzoate)] thermotropic copolyesters were prepared by the copolymerization of poly(ethylene terephthalate) (PET) as moiety (II) and p-acetoxybenzoic acid (POB) as moiety (I). The polymeric products obtained were subjected to solid-state polymerization. Characterization of the copolyesters by thermomechanical analysis shows that properties such as the coefficient of thermal expansion, transition temperature, and maximum softening rate temperature varied directly as a function of composition as well as did solid-state polymerization time. All thermomechanical data were found to increase with the solid-state polymerization time due to the increase in the degree of polymerization and the effect of annealing. The coefficient of thermal expansion behaves in a manner that is interpretable by the crystalline state of the copolyester. The relationship between the free-volume fraction and thermodynamic properties is further correlated for a more comprehensive discussion on its molecular arrangements. © 1995 John Wiley & Sons, Inc. 相似文献
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研究了聚对苯二甲酸丙二醇酯 (PTT) ,PET ,CDP在不同温度和时间下的特性粘数和端羧基含量的变化。结果表明 ,一定温度下 ,PTT熔体特性粘数随熔融时间的延长而下降 ,一定时间下 ,随温度的升高而下降。PTT端羧基含量随温度升高而增大 ,PTT的热稳定性较PET明显下降。 相似文献
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High molecular weight phosphorus-containing copolyesters, poly(ethylene terephthalate)-co-poly(ethylene DDP) (PET-co-PEDDP)s, were prepared and characterized with the objective of producing a non-halogen flame retardant system for practical applications. The phosphorus-containing copolyester with 30 wt% phosphorus (P30 copolyester) was blended with PET to evaluate their characteristics and flame retardancy. Higher phosphorus content results in lower crystallinity and higher char formation after thermal degradation. The rheological behavior remains similar to that of PET. The P30/PET blend possesses higher crystallization rate than the corresponding phosphorus-containing copolyester containing equal phosphorus content. Thermal and rheological behaviors of P30/PET blends are similar to PET or the phosphorus-containing copolyesters. The P30/PET blends are miscible or compatible base on single Tgs detected by DSC or DMA. The SEM/EDX phosphorus mapping image of the P30/PET blend shows uniform distribution of the phosphorus moieties within the P30/PET matrix, another indication of a compatible or miscible blend between the phosphorus-containing copolyester P30 and PET. Flame retardancy of the P30/PET blend is identical to that of the phosphorus-containing copolyester with identical phosphorus content. Blending of high phosphorus content copolyester with virgin PET provides a feasible method to obtain a flame resistant PET with LOI greater than 28. 相似文献
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采用生物法1,3-丙二醇(PDO)直接酯化缩聚合成聚对苯二甲酸丙二醇酯(PTT),通过IR、1H NMR、DSC 和TG方法对其进行了表征,并与化学法PDO合成的PTT进行比较。结果表明,生物法PDO合成的产物是PTT;生物法PDO合成的PTT比同一纯度的化学法PDO合成的PTT色泽好、粘度大、摩尔质量高,且随PDO纯度提高,PTT粘度、摩尔质量增大;生物法PDO合成的PTT熔点与化学法PDO合成的PTT相差不大,熔融峰比化学法PDO合成的PTT 尖锐,熔融热大,结晶度高;不同PDO合成的PTT树脂热失重相差不大,表明PDO不同对PTT热分解行为影响不大。 相似文献
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The objective of this study is to use the copolymerization method to improve the thermal shrinkage property of poly(ethylene terephthalate) (PET), so that the resultant copolyester can be used for the application of thermal shrinkage packing materials. The poly(ethylene isophthalate terephthalate) (PEIT) copolyester films were prepared and studied. The thermal shrinkage rate of PET films and the thermal shrinkage rate of the copolyester films were measured by using a thermomechanical analyzer (TMA). The thermal shrinkage of copolyester was found to be dependent on such factors as composition, molecular weight, and draw temperature. The highest thermal shrinkage was obtained when the copolymer contained 40 mol % of ethylene isophthalate. Its shrinkage ratio and shrinkage rate were consistently 1.3 and 2.4 times those of PET. The increase of molecular weight and decrease of drawing temperature resulted in the increase of the thermal shrinkage. The best drawing temperature range was between glass transition temperature and soft temperature of the copolymer. The relationship of shrinkage rate and temperature indicate that the shrinkage mechanism of the copolyester belongs to two-step thermal shrinkage. 相似文献
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K NalampangA.F Johnson 《Polymer》2003,44(19):6103-6109
The kinetics of the individual key reactions involved in the formation of unsaturated polyester resins have been studied using the very reactive glycol, 2-methyl-1,3-propanediol (MPD). This diol has been reacted in turn with maleic anhydride (MA), phthalic anhydride (PA) and isophthalic acid (IA) under isothermal conditions in the temperature range 180-210 °C and the kinetic constants for the following reactions have been obtained MA+MPD, PA+MPD, IA+MPD, MA+PA+MPD and MA+IA+MPD. The relative reactivities of MPD with MA and PA measured by monitoring the loss of carboxyl groups at 180 and 200 °C were found to be 2.26 and 1.70, respectively. At 200 °C PA is more reactive than IA (ratio approximately 1.31) in homopolyesterification. In the copolyesterifications involving PA and IA where cross catalysis can occur, the PA reacted approximately 1.25 times faster than IA at 200 °C. The differences in reactivity might be expected to have a significant effect on the coreactant sequence lengths in prepolymers formed by the concurrent reaction of PA, IA and MPD particularly at low conversions thus on the final properties of the cured resins in which they are employed. The properties of the products are not examined in this paper. 相似文献
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以甘油为原料经氯代、环化、加氢反应3步合成了1,3-丙二醇。较优的反应条件为:氯代反应在醋酸(质量分数为6%)为催化剂、温度90℃反应3.5 h;环化反应在n(3-氯-1,2-丙二醇)∶n(氢氧化钠)=1∶1、氢氧化钠的质量分数为40%、温度为0℃反应1.5 h;加氢反应在钴-氧化镁/硅胶作催化剂、n(氢气)∶n(环氧丙醇)=10∶1、环氧丙醇的质量分数为20%、温度为100~150℃反应4 h;1,3丙二醇的总产率可达58.6%。 相似文献