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聚氧硫杂蒽树脂固化特性及其动力学的研究 总被引:12,自引:0,他引:12
以DSC、TG等技术手段研究了聚氧硫杂蒽树脂 (POSPF)的固化特性及其动力学 .结果表明 ,用六次甲基四胺 间二氯苄作固化剂 ,加热至 10 5~ 2 2 5℃能使POSPF树脂固化 ,在固化过程树脂中的活性羟甲基和固化剂参与反应生成亚甲基桥从而形成网状体型结构 ;动态DSC曲线上出现宽的固化放热峰 ,用T β外推法确定其凝胶温度Ti=10 0 0℃、固化温度Tp=181 5℃、后固化温度Tf=2 2 5 7℃ .固化后树脂具有优良的耐热性 ,失重 5 %时热分解温度高达 4 0 3℃ . 相似文献
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以呫吨酮为起始原料,经二氯亚砜作用得到9,9-二氯呫吨中间体,继而与苯酚发生取代反应,探索了"一锅、二步"法制备含呫吨结构的双酚单体———9,9-二(4-羟基苯基)呫吨(BHPX)的新方法.在氮气保护下,在K2CO3存在下,以环丁砜为溶剂,将其与1,3-二(4-氟苯甲酰基)苯进行亲核缩聚反应,制得了一种高分子量的(数均分子量为45000,多分散性指数为1.9)新型含呫吨结构的Cardo型聚醚醚酮酮(PEEKK-X),并用FTIR,DSC,TG及WAXD等方法对其进行了分析表征.结果表明,所制得的聚合物(PEEKK-X)为无定形结构,其玻璃化转变温度(Tg)为215℃;在氮气气氛中5%的热失重温度(Td)为558℃,700℃时的残炭率为67%;在常温下易溶于非质子极性溶剂(如NMP、DMF和DMAc)和极性较弱的溶剂如CHCl3中.该聚合物可通过溶液浇铸成膜,所得到的薄膜韧性好,透明且耐折,其拉伸强度为81.5 MPa,杨氏膜量为2.48 GPa,断裂伸长率为16.8%. 相似文献
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以含羧基侧基的聚芳醚酮酮醚酮酮(PEKKEKK-A)树脂为原料,二氯亚砜(SOCl2)、二氯乙烷(DCE)、吡啶为催化溶剂体系,合成带甲酰氯侧基的聚芳醚酮酮醚酮酮(PEKKEKK-C)树脂.PEKKEKK-C与甲醇、乙醇、丁醇、辛醇、苯酚等发生酯化反应,得到5种含羧酸酯侧基的聚芳醚酮酮醚酮酮(PEKKEKK-E)s.用红外光谱(FTIR)、氢核磁谱(1H-NMR)、广角X射线衍射(WAXD)、热失重(TGA)、示差扫描量热(DSC)等技术对其结构与性能进行了分析表征.结果表明,聚合物为非晶聚集态;玻璃化转变温度(Tg)在175.7~236.8℃之间,较PEKK有较大幅度提高;出现两次热失重平台,分别在335~365℃,460~505℃之间,第一次失重可能由于酯分解所致,第二次失重可能是分子主链开始分解;树脂能溶解于DMAc、NMP、二氯甲烷等普通有机溶剂中,溶剂挥发后成膜性良好,可制成透明薄膜;断裂伸长率在6.34%~15.43%之间,拉伸强度在74.68~85.35MPa之间。 相似文献
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In this paper, we are interested in the existence and multiplicity results of solutions for the singular quasilinear elliptic problem with concave–convex nonlinearities (0.1) where is an unbounded exterior domain with smooth boundary ?Ω, 1 < p < N,0 ≤ a < (N ? p) ∕ p,λ > 0,1 < s < p < r < q = pN ∕ (N ? pd),d = a + 1 ? b,a ≤ b < a + 1. By the variational methods, we prove that problem 0.1 admits a sequence of solutions uk under the appropriate assumptions on the weight functions H(x) and H(x). For the critical case, s = q,h(x) = | x | ? bq, we obtain that problem 0.1 has at least a nonnegative solution with p < r < q and a sequence of solutions uk with 1 < r < p < q and J(uk) → 0 as k → ∞ , where J(u) is the energy functional associated to problem 0.1 . Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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A new method is proposed to represent the bipolar states of a neural network. An optoelectronic system based on an inner-product multiplier is suggested to implement the bipolar associative memory which has a larger storage capacity and a higher error-correction capability than those of unipolar one. The experimental results are also given and discussed. 相似文献
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The J_2-integral induced from the interface of bimaterial solids(J_2~(interface))is stud-ied by numerical method.First,the effect on the J_2-integral induced from the interface is verysignificant in bimaterial solids,which is inherently related to that induced from the subinterfacecracks.Moreover,it can be concluded that either the first or the second component of the J_k-vector is always equal to zero when the contour encloses both the cracks and the whole interfacein bimaterial solids.Secondly,it can also be concluded that the interface does produce significanteffect on the J_2-integral induced from the subinterface cracks(J_2~(sub))in bimaterial solids.Thiseffect depends on the geometry of the crack arrangement,which is corresponding to the differentinteraction effect among the cracks and the interface.Moreover,the interface effect on the J_2~(sub)can be neglected when the distance from the crack center to the interface is large enough,whichreveals that the bimaterial solids can be regarded as homogenous solids in fracture analysis whenthe subinterface crack is far enough from the interface.Three examples are given in this paper. 相似文献
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A new monomer, 4,4′‐bis(4‐phenoxybenzoyl)diphenyl(BPOBDP), was synthesized via a two‐step synthetic procedure. A series of novel poly(ether sulfone ether ketone ketone)/poly(ether ketone diphenyl ketone ether ketone ketone) copolymers were prepared by electrophilic Friedel–Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of 4,4′‐diphenoxydiphenylsulfone (DPODPS) and 4,4′‐bis(4‐phenoxybenzoyl)diphenyl (BPOBDP), in the presence of anhydrous aluminum chloride and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The copolymers with 10–50 mol% DPODPS are semicrystalline and have remarkably increased Tgs over commercially available PEEK and PEKK. The copolymers with 40–50 mol% DPODPS had not only high Tgs of 170–172°C, but also moderate Tms of 326–333°C, which are extremely suitable for melt processing. These copolymers have tensile strengths of 96.5–108.1 MPa, Young's moduli of 1.98–3.05 GPa, and elongations at break of 13–26% and exhibit excellent thermal stability and good resistance to acidity, alkali, and common organic solvents. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献