摘要:
A process for the preparation of a polyphenylene layer which comprises the steps of treating a copolycyclohexa-3,4-diene under first conditions to aromatize a portion of the aromatic rings and then under second conditions to aromatize the residual cyclohexadiene rings from the first treatment.
摘要:
A solvent-free preform of a 3-hydroxybutyric acid polymer is subjected to a compression step to reduce its thickness by at least 5% and the compressed preform is then drawn uni- or bi- axially to induce orientation.
摘要:
Degradation of body-waste bags to assist disposal thereof in sewage systems is facilitated by addition of a base to raise the pH of the human fecal waste bag contents to at least about 12. Inter alia, there is provided a package of at least one bag and sufficient base, preferably in prepacked quantities, to treat all the bags in the package.
摘要:
Polymer blends containing (i) 0.2-95% by weight of a high molecular weight .beta.-hydroxybutyric acid homo- or copolymer and (ii) a polymer containing at least 25% by weight of chlorine or nitrile groups, such as chlorinated polyethylene, polyvinyl chloride, or a high acrylonitrile resin.In small quantities the .beta.-hydroxybutyric acid polymer acts as a processing aid for the chlorine or nitrile containing polymer.In larger quantities the properties of the .beta.-hydroxybutyric acid polymer or the chlorine or nitrile containing polymer are improved.
摘要:
Shaped articles can be made by extruding, or injection moulding, a composition containing at least 50% by weight of dried cells of a micro-organism containing a .beta.-hydroxybutyrate polymer. In order to make the composition melt processable the cells are subjected to a cell wall breakage step before or after drying and, if necessary, are mixed with an extracted .beta.-hydroxybutyrate polymer.
摘要:
High molecular weight copolymers containing 3-hydroxybutyrate residue, i.e. units of the formula--O.CH(CH.sub.3).CH.sub.2.CO--and up to 50 mole % of residues of other hydroxy acids, viz units of the formula--O.CR.sup.1 R.sup.2.(CR.sup.3 R.sup.4).sub.n.CO--where n is 0 or an integer and, if n=1 and R.sup.2, R.sup.3, and R.sup.4 =H, R.sup.1 is not methyl.The copolymers are made microbiologically: for part of the cultivation the micro-organism is under conditions such that polymer is accumulated, e.g. by limitation of a nutrient, e.g. nitrogen source, required for growth but not polyester accumulation. For at least part of this period of polymer accumulation the substrate is an acid or a derivative thereof that gives the comonomer units. Proprionic acid, which gives polymers where n=1, R.sup.2 =R.sup.3 =R.sup.4 =H and R.sup.1 =C.sub.2 H.sub.5, is the preferred acid.
摘要:
An improved plasticized polyvinyl chloride interlayer for laminated safety glass, and an improved method of manufacturing a laminated safety glass including such plasticized polyvinyl chloride containing film is disclosed. An improved functional silane adhesion promoter is utilized in such a manner so as to impact energy dissipation is maximized while structural integrity is maintained. The plasticized polyvinyl chloride interlayer is formulated so as to provide improved long term heat stability at service use temperatures.
摘要:
An aqueous suspension of micro-organism cells containing a 3-hydroxybutyrate polymer are subjected to a proteolytic enzyme digestion and/or a surfactant digestion in order to solubilise cell material other than the 3-hydroxybutyrate polymer.Prior to, or during the digestion, but before any proteolytic enzyme digestion step, the suspension is heated to at least 80.degree. C. to denature nucleic acids which otherwise hinder separation of the 3-hydroxybutyrate polymer containing residue from the suspension.
摘要:
3-Hydroxybutyrate polymers are formed into oriented shaped articles by drawing a partially crystallized preform to increase at least one dimension by at least 200%, and then increasing the degree of crystallization while maintaining the drawn preform in the drawn condition.