CRYSTAL STRUCTURE OF POLY-ETA-CAPROLACTONE
CRYSTAL STRUCTURE OF POLY-ETA-CAPROLACTONE
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DOI：
10.1107/s0567740870005198
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发表时间：
1970-01-01
期刊：
影响因子：
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通讯作者：
NIEGISCH, WD
中科院分区：
文献类型：
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作者：
BITTIGER, H;MARCHESSAULT, RH;NIEGISCH, WD
聚ε-己内酯的晶胞为正交晶系，晶胞参数a= 7.496+ 0.002，B= 4.974+ 0 - 001，c= 17.297+ 0-023/~（纤维轴）。空间群为P212121。该晶胞仅与涉及两个单体残基的分子的延伸平面链构象相容，所述两个单体残基在链方向上由双螺旋轴相关。空间群为P212~ 2~，密度为1.146g. cm-3表示晶胞含有两个方向相反的链（“上”和“下”）。强度测量和结构因子计算需要将链的平面围绕其轴旋转到相对于a轴的28 °角;纵向链移位将酯基放置在垂直于c轴的平面中。通过电子显微镜观察到具有柳叶刀状结构的折叠链单晶。引言通过内酯开环聚合制备的聚酯由于新的聚合催化剂而变得突出（Chujo，小林，铃木，Tokyhara &田边，1967; Asahara & Katayama，1964; Alderson，1956; Okamura，Higashimore & Ta-naka，1962）。这类大分子与传统的聚酯有本质上的不同（Fuller & Frosch，1939; Fuller & Erikson，1957），因为链内酯基的均匀取向使链具有方向感。根据链中酯基之间的距离及其相互作用，可以发现链的不同分子内或分子间排列。例如，已经发现聚丙内酯可以以两种不同的多晶型物存在，分别具有延伸构象和螺旋构象（Wasai，Saegusa & Furakawa，1964）。近年来特别感兴趣的是具有连接到主链上的侧基的聚酯。如聚-F1-H。羟基丁酸酯（Okamura & Marches-sault，1967）和聚新戊内酯（Knobloch & Statton，1967），所述羟基丁酸酯作为光学活性天然聚合物存在，所述聚新戊内酯是一种令人感兴趣的合成纤维材料。聚己内酯由ε-己内酯开环聚合而成，具有如下结构：
The unit cell of poly-e-caprolactone was found to be orthorhombic with dimensions a= 7.496+ 0.002, b= 4.974+ 0" 001, c= 17.297+ 0-023/~(fiber axis). The space group is P212121. This unit cell is only compatible with an extended planar chain conformation of the molecule involving two monomer residues related by a twofold screw axis in the chain direction. The P212~ 2~ space group and the density of 1.146 g. cm-3 indicate that the unit cell contains two chains with opposite orientation ('up'and'down'). Intensity measurements and structure factor calculations require the rotation of the plane of the chains about their axis to an angle of 28 with respect to the a axis; longitudinal chain shift places the ester groups in planes perpendicular to the c axis. Folded chain single crystals with a lancet-like structure were observed by electron microscopy.Introduction Polyesters prepared by ring opening polymerization of lactones are coming into prominence as a result of new polymerization catalysts (Chujo, Kobayashi, Suzuki, Tokyhara & Tanabe, 1967; Asahara & Katayama, 1964; Alderson, 1956; Okamura, Higashimore & Ta-naka, 1962). Such macromolecules are intrinsically dif-ferent from conventional polyesters (Fuller & Frosch, 1939; Fuller & Erikson, 1957) in that the chain has a sense of direction by the uniform orientation of the ester groups within the chains. Depending on the dis-tance between the ester groups in the chains and their interactions one can find different intra-or intermole-cular arrangements of the chains. For example, it has been found that polypropiolactone can exist in two dif-ferent polymorphs with an extended and helical con-formation respectively (Wasai, Saegusa & Furakawa, 1964). Of particular interest in recent years have been polyesters with side groups attached to the main chain such. as poly-fl-h. ydroxybutyrate (Okamura & Marches-sault, 1967) which occurs as an optically active natural polymer and polypivalolactone (Knobloch & Statton, 1967) which is an interesting synthetic fiber mate-rial. Poly-e-caprolactone. made by ring opening poly-merization of e-caprolactone has the following struc-ture: