Disclosed is a preparation method for polylactic acid grafted chitosan nanowhiskers, and belongs to the technical field of materials. The preparation method of the disclosure is that after lactide, a catalyst and chitosan are uniformly mixed, polymerization grafting is performed to prepare PLA-g-CS, and then the PLA-g-CS is dispersed into an alkali liquor to obtain nanowhiskers by a repeated freezing/unfreezing method, with no solvent used in a polymerization grafting process. The method has advantages that the nanowhiskers can be prepared from the PLA-g-CS without a good solvent, and the whole reaction is efficient, clean, and environmentally friendly.

The present invention relates to a method for preparing a polyester carbonate starting from cycloaliphatic diacids and aliphatic diols and to the polyester carbonate prepared by the method. The method according to the invention is a direct synthesis in which all the structural elements that form the subsequent polyester carbonate are already present as monomers in the first step of the method.

The present invention relates to a method for preparing a polyester carbonate starting from cycloaliphatic diacids and aliphatic diols and to the polyester carbonate prepared by the method. The method according to the invention is a direct synthesis in which all the structural elements that form the subsequent polyester carbonate are already present as monomers in the first step of the method.

A method of producing a degradable material includes steps of providing δ-valerolactone 2-ethylidene-6-hepten-5-olide (EVL) or other suitable monomer; combining the EVL or other suitable monomer with a catalyst to form a reaction mixture; and subjecting the reaction mixture to conditions that will allow the EVL or other suitable monomer to react in the presence of the catalyst to thereby form a product composition including a polymer of the EVL or other suitable monomer, where the polymer is hydrolytically degradable.

The present disclosure discloses a liquid crystal polyester (LCP), an LCP composition, and use thereof. The LCP includes a repeating unit of formula (1), a repeating unit of formula (2), and a repeating unit of formula (3): (1) —O—Ar.sup.1—CO—, (2) —CO—Ar.sup.2—CO—, and (3) —O—Ar.sup.3—O—, where Ar.sup.1 is at least one selected from the group consisting of 2,6-naphthylene, 1,4-phenylene, and 4,4′-biphenylene; Ar.sup.2 is selected from the group consisting of 1,4-phenylene, 1,3-phenylene, and 4,4′-biphenylene; and Ar.sup.3 is selected from the group consisting of 2,6-naphthylene, 1,4-phenylene, 1,3-phenylene, and 4,4′-biphenylene; and the LCP has a melting enthalpy of over 1.5 J/g. The LCP and the composition including the LCP of the present disclosure have a high heat deflection temperature (HDT), and exhibit excellent heat resistance and anti-bubbling performance.

The present disclosure discloses a liquid crystal polyester (LCP), an LCP composition, and use thereof. The LCP includes a repeating unit of formula (1), a repeating unit of formula (2), and a repeating unit of formula (3): (1) —O—Ar.sup.1—CO—, (2) —CO—Ar.sup.2—CO—, and (3) —O—Ar.sup.3—O—, where Ar.sup.1 is at least one selected from the group consisting of 2,6-naphthylene, 1,4-phenylene, and 4,4′-biphenylene; Ar.sup.2 is selected from the group consisting of 1,4-phenylene, 1,3-phenylene, and 4,4′-biphenylene; and Ar.sup.3 is selected from the group consisting of 2,6-naphthylene, 1,4-phenylene, 1,3-phenylene, and 4,4′-biphenylene; and the LCP has a melting enthalpy of over 1.5 J/g. The LCP and the composition including the LCP of the present disclosure have a high heat deflection temperature (HDT), and exhibit excellent heat resistance and anti-bubbling performance.

The invention relates to a process for producing a polyester by reacting a H-functional starter substance with a lactone in the presence of a catalyst, wherein the H-functional compound has one or more free carboxyl groups, wherein the lactone is a four-membered ring lactone, and wherein the catalyst is a Brönsted acid or a double metal cyanide (DMC) catalyst. The invention also relates to the polyester that can be obtained by the present invention.

Provided are integrated processes for the conversion of beta propiolactone to acrylic acid. Systems for the production of acrylic acid are also provided.

A method for synthesizing regioregular polyesters, starting from asymmetric diols, may provide the polymer ordered structure and advantageous physical-chemical properties. Such methods can make it is possible to obtain regioregular polyesters having high glass transition temperatures T.sub.g and crystalline properties. In the case in which the asymmetric diols are used in a pure enantiomeric form, with respect to the chiral carbon bound to the secondary hydroxyl, through the above-mentioned method it is possible to obtain regioregular and stereoregular polyesters, which may have thermal and crystalline properties further ameliorative with respect to non-chiral regioregular polymers.

Disclosed is a method for preparing polylactone by ring opening, belonging to the technical fields of organic catalysis and polymer materials. The invention proposes a new catalytic mechanism, wherein an organic alcohol is used as an initiator to initiate ring opening polymerization of a cyclic monomer under the catalysis of an organic catalyst to obtain a polylactone; and the catalyst is a pyridinium salt. The present invention has the advantages of non-toxic reaction, simple conditions and controllable process; further, the invention can obtain a narrow molecular weight distribution in the absence of solution polymerization, and can effectively inhibit the occurrence of the transesterification compared with the catalysis of 4-(N,N-dimethylamino)pyridine.