The abnormal joining of anatomic structures after abdominal and pelvic surgery can lead to such major complications as bowel obstruction or infertility. Poly(vinyl alcohol) (PVA) membranes and hydrogels were placed over the injured tissue to act as a physical barrier and prevent such adhesions from occurring in a rabbit sidewall model. The membranes were sutured into place to prevent their slipping or curling on the moist tissue. Various in vitro experiments (including testing for swelling and mechanical strength) were conducted in order to better understand the behavior of these membranes in the wound. The results showed that both the PVA membranes and PVA hydrogels significantly reduced the number and severity of adhesions in the rabbit sidewall model, and even indicated a distinct improvement over SEPRAFILM as antiadhesion barriers. Contact-angle measurements were taken in order to evaluate the surface properties of the membranes and hydrogels. Three approaches were taken to render the membranes more bioadhesive, and forego the need for future additional suturing: imprinting a texture onto the membrane, coating the membrane with carboxy methyl cellulose (CMC), and producing bi-layered, porous PVA membranes through a process of lyophilization. Though the surface of the PVA hydrogels is more hydrophilic than the surface of the PVA membranes, neither would adhere untreated to moist tissue. However, all three approaches aimed at improving their bioadhesion yielded excellent results and demonstrated that PVA could indeed be considered a viable method of adhesion prevention.

The pendant drop apparatus is used in order to study the surface tension of ethene-1butene random copolymer melts over the whole range of compositions, including poly(1-butene) (P-1-B) and at different temperatures. Furthermore, the surface tensions of isotactic polypropene (i-PP) and syndiotactic polypropene (s-PP) are measured. The surface tension of the melt of random copolymers decreases as a function of copolymer composition from pure polyethene (PE) to pure P-1-B in a nearly exponential manner, and the surface tensions of copolymers with a P-1-B content in the range of approximately 40 wt % match the surface tension of i-PP and s-PP. This indicates the possible existence of a window of miscibility. This result is verified by the calculation of the solubility parameters from additional sessile drop measurements on solid copolymers at room temperature and from pressurevolume-temperature data of the melts applying the Flory-Orwoll-Vrij equation-of-state theory. Also, the theory of the conformational parameter β (Bates and Fredrickson) leads to the same conclusion. All results are consistent with microscopic observations discussed in the literature.

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The surface tension of molten LDPE can be determined with the help of the pendent drop method, depending on the temperature and on the surfactant added. The critical micelle concentration was reached on addition of 1% of the surfactant. A four‐component mixture consisting of HDPE, LDPE, PVC, and PS, whose composition corresponded to that of collected waste plastics, was used to study the effects of the addition of surfactants on the applicational properties.