巻号一覧
2 巻 (1990)
- 6 号 p. 485-
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- 3 号 p. 227-
- 2 号 p. 141-
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2 巻, 3 号
選択された号の論文の3件中1～3を表示しています
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中村 行雄, 米岡 典永, 八川 修一1990 年 2 巻 3 号 p. 227-234
発行日: 1990/06/20
公開日: 2009/11/18
ジャーナル フリーPDF形式でダウンロード (2440K) -
後藤 昌生, 飯田 誠, 宮野 靖, 新保 實1990 年 2 巻 3 号 p. 243-249
発行日: 1990/06/20
公開日: 2009/11/18
ジャーナル フリーThe dependence of impact properties on talc content and molecular weight (M) of polypropylene (PP) were investigated for talc-filled polypropylene (f-PP). The following results were obtained.
(1) For impact, a fracture mode transition from ductile to brittle exists, regardless of the presence of filler. The impact strength (IS) of PP increases rapidly with increasing temperatures above the ductile-brittle transition temperature (Tdb).
(2) The IS of PP depends strongly on molecular weight, but in f-PP, this dependence is decreased with increasing talc content at temperatures above Tdb.
(3) The Tdb of f-PP increases (-20→0°C) with increasing talc content (25→55wt%). The Tdb of PP is almost constant for the molecular weight range of 2.70×104∼6.71×104 despite the different flow properties (MFI=ca. 1∼26g/10min).
(4) The dependence of IS on talc content for f-PP at temperatures above Tdb is mainly controlled by fracture strain ε rather than fracture stress σ.
(5) Increasing the molecular weight of PP is an effective way to increase the impact strength IS. The use of talc filler shifts Tdb to higher temperatures. These results provide the basic concepts for material design for impact strength.抄録全体を表示PDF形式でダウンロード (1136K) -
石橋 達弥, 蒲沢 英喜, 小奈 弘, 吉田 秀敏, 手塚 孝治1990 年 2 巻 3 号 p. 250-259
発行日: 1990/06/20
公開日: 2009/11/18
ジャーナル フリーThis paper describes a convenient method to determine the viscoelastic properties of plastics based on short time relaxation tests after constant strain rate uniaxial compression. This method does not require special testing equipment, can be performed on ordinary material testing machines in the factory, and is based on an extension of the Testing Method for Compressive Properties of Plastics (JIS K 7208). In this paper, we analyze stress relaxation curves obtained from the tests mentioned above and discuss a simple method based on a 6-parameter viscoelastic model (3 parallel Maxwell elements). This model is based on an approximation of stress relaxation to a three story structure and an introduction of two differential coefficients at the initiation of stress relaxation. Furthermore, for wide application to a range of viscoelastic behavior, concrete reducible equations between two equivalent 6-parameter viscoelastic models are shown.抄録全体を表示PDF形式でダウンロード (1140K)
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